JP4881674B2 - Developing device and image forming apparatus - Google Patents

Description

  The present invention relates to a developing device in an image forming apparatus such as a copying machine, a printer, and a facsimile.

JP 2002-229318 A

  A developing device in which a toner cartridge is detachably provided in the developing device main body is well known, for example, from Patent Document 1. Further, the applicant of the present application has previously proposed a developing device and an image forming apparatus that prevent the toner from dropping and improve the operability when the cartridge is attached and detached.

  13 and 14 show an unpublished developing device previously proposed by the applicant of the present application. FIG. 13 shows the developing device main body 131, and FIG. 14 shows the developing device main body 131. A toner cartridge 137 that supplies toner to 131 is shown.

  As shown in FIG. 13, a toner supply port 39a provided in the developing device main body 131 is provided with a shutter mechanism 90 that opens and closes the toner supply port 39a. The shutter mechanism 90 includes a slide plate 91 and an elastic member 92, and the elastic member 92 is attached to one surface of the slide plate 91. The shutter mechanism 90 is slidably mounted on the inner side surface of the developing device main body 131 provided with the toner supply port 39a.

  On the other hand, as shown in FIG. 14, the toner cartridge 137 also has a toner supply port 39b on the side surface of the cartridge, and includes a shutter mechanism 100 that opens and closes the toner supply port 39b. The shutter mechanism 100 includes an elastic member 94 attached to the side surface of the cartridge so as to cover the periphery of the toner supply port 39b, a slide plate 95 that is slidably supported outside the elastic member 94, and the slide plate. 95, and a fixed seal 96 disposed on the outer side.

  By inserting and setting the toner cartridge 137 into the main body of the developing device 131 and opening the shutter mechanisms 90 and 100, the cartridge and the toner supply ports 39b and 39a on the main body side communicate with each other. When the toner cartridge 137 is set in the developing device main body 131, gears (not shown) provided on the main body side and the cartridge side mesh with each other, and an agitator (not shown) provided in the toner cartridge 137 is rotationally driven. Thus, toner is supplied from the cartridge 137 to the developing device main body 131 through the toner supply ports 39b and 39a.

  In the above-described configuration, in the shutter mechanism 100 provided in the toner cartridge 137, the order of the members with respect to the side surface of the cartridge is the order of the elastic member 94, the slide plate 95, and the fixed seal 96 from the inside. Even when the toner cartridge 137 is removed from the developing device main body 131, the toner is present in the opening 94a of the elastic member 94 (the toner is placed on the member thickness of the opening or the toner is clogged in the opening). The toner is prevented from leaking to the outside by the outer slide plate 95 and the fixed seal 96 (the toner plate is prevented from leaking by the displacement of the openings 95a and 96a of the slide plate 95 and the fixed seal 96 when the shutter is closed). ).

  However, since the shutter mechanism 90 on the developing device main body 131 side has no seal member or the like outside the elastic member 92, the toner in the opening 92a of the elastic member 92 is affected by the impact when the cartridge is attached / detached. The cartridge may fall into the cartridge setting unit 40. The toner dropped on the set unit 40 is gradually scraped toward the cartridge insertion / removal port by further attachment / detachment of the cartridge, and may eventually fall out of the developing device.

  As described above, in the developing device in which the toner cartridge is detachably provided in the developing device main body, even when both the toner replenishing port portions are provided with the shutter mechanism, the toner dropped from the shutter mechanism portion to the cartridge setting portion is finally There has been a problem that it may leak out of the developing device.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a developing device and an image forming apparatus that solve the above-described problems in a conventional developing device in which a toner cartridge is detachably provided, and can prevent contamination due to toner dropping with a simple configuration. To do.

According to the present invention, the toner cartridge is detachably provided in the developing device main body, and the toner is replenished from the toner replenishing port provided in the toner cartridge through the toner replenishing port provided in the developing device main body. In the developing device having a shutter mechanism in each of the toner replenishing port of the toner cartridge and the toner replenishing port of the developing device main body, the falling toner is received at a lower position of the shutter mechanism of the developing device main body. A toner receiving portion is provided , the toner receiving portion includes a plurality of receiving portions, and the toner receiving portion including the plurality of receiving portions includes a toner receiving portion positioned at an end portion on the toner cartridge outlet side. This is solved by providing a seal member that is in sliding contact with the bottom surface of the cartridge .

Further, it is preferable that the toner receiving portion is formed as a concave portion in which a part of the unit case of the developing device main body is recessed.
Further, it is preferable that the toner receiving portion is formed by closing a bottom portion of a through hole provided through a part of a unit case of the developing device main body with another member.

The seal member is preferably an elastic member.
The seal member is preferably a flocking member.
Further, it is preferable that the shutter mechanism of the developing device main body is provided with an elastic member on the outermost side.

The shutter mechanism of the toner cartridge is preferably provided with a sheet-like member having excellent slidability on the outermost side.
In addition, according to the present invention, the above problem is solved by an image forming apparatus including the developing device according to any one of claims 1 to 7 .

  According to the developing device and the image forming apparatus of the present invention, since the toner receiving portion for receiving and storing the dropped toner is provided at the lower position of the shutter mechanism of the developing device main body, even when the toner falls from the shutter mechanism, The falling toner can be received and stored at the receiving portion, and the falling toner can be prevented from leaking outside the developing device. In the present invention, toner leakage to the outside of the developing device can be prevented with a simple configuration by receiving and storing the toner dropped from the shutter portion by the toner receiving portion, regardless of the configuration of the shutter mechanism.

  According to the configuration of the second aspect, since the toner receiving portion is formed as a concave portion in which a part of the unit case of the developing device main body is recessed, the configuration for preventing toner leakage is simplified and the configuration of the device is complicated. And there is no increase in cost and weight.

  According to the third aspect of the present invention, the toner receiving portion is formed by closing the bottom portion of the through hole provided through a part of the unit case of the developing device main body with another member. It is possible to prevent the leakage of the falling toner.

According to the configuration of the fourth aspect , since the sealing member is an elastic member, the sealing member can be easily configured at low cost.
According to the configuration of the fifth aspect , since the sealing member is a flocking member, each fiber of the flocking member can be wiped following the shape of the back surface of the cartridge, and the wiping property can be improved.

According to the sixth aspect of the present invention, since the elastic member is disposed on the outermost side of the shutter mechanism of the developing device main body, it is possible to improve the sealing performance of the shutter mechanism and reliably prevent toner leakage from the developing device main body.

According to the configuration of the seventh aspect , since the sheet-like member having excellent slidability is disposed on the outermost side of the shutter mechanism of the toner cartridge, the slidability with respect to the elastic member of the main body side shutter mechanism is ensured, and the cartridge is attached / detached Can be improved.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a cross-sectional view showing a schematic configuration of a color copying apparatus which is an example of an image forming apparatus to which the present invention is applied. The overall configuration and operation of this color copying apparatus will be described later, and the developing apparatus that is the gist of the present invention will be described first.

  As shown in FIG. 2, each developing device 31M, C, Y, K of the developing unit 30 has a developing sleeve 32 that rotates while carrying toner on the surface in order to develop an electrostatic latent image on the surface of the photoreceptor belt 11. And a developing first unit 35 including a toner paddle 33 that rotates to pump up and stir the toner, a toner replenishing roller 34, and a doctor roller 36, and a developing second unit 37 that is a toner cartridge that contains toner. It consists of The reason why the development first unit 35 is divided into two units in this manner is that the development first unit 35 has durability that can withstand even when the development second unit 37 is replaced. In the developing second unit (toner cartridge) 37, biaxial agitators 38, 38 are provided.

  The toner is supplied from the toner cartridge 37 as the second developing unit to the first developing unit 35 through the toner supply port 39. The agitator 38 provided in the toner cartridge 37 rotates to draw up the toner, and the toner is supplied to each developing first unit 35 from the supply port 39.

  FIG. 3 is a perspective view showing the first developing unit 35 that is the main body of the developing device 31 with the toner cartridge 37 removed. FIG. 4 is a perspective view of the toner cartridge 37 as the second developing unit. The developing device main body 31 (developing first unit 35) and the toner cartridge 37 (developing second unit) of this example have the same basic configuration as the developing device main body 131 and the toner cartridge 137 described with reference to FIGS. The same or equivalent parts are denoted by the same reference numerals.

  As shown in FIGS. 3 and 4, the developing device 31 is provided with a toner replenishing port 39 a on the side surface (the surface facing the toner cartridge 37) of the first developing unit 35. The toner replenishing port 39a is provided corresponding to almost the entire width of the image forming width, and includes a plurality of openings. A shutter mounting portion is provided on the inner surface of the first unit provided with the toner supply port 39a, and the shutter mechanism 90 is slidably mounted as shown by an arrow in FIG. The shutter mechanism 90 includes a slide plate 91 and an elastic member 92, and the elastic member 92 is attached to one surface of the slide plate 91. The slide plate 91 and the elastic member 92 are provided with a plurality of openings (only the opening 92a of the elastic member 92 is shown) corresponding to the toner supply port 39a. The plurality of openings provided in the slide plate 91 and the elastic member 92 are provided in the same shape and in the same position as the toner supply port 39a, and the shutter mechanism 90 is slid to move the shutter side opening 92a (and the slide plate 91). The toner supply port is opened when the opening (not shown) coincides with the toner supply port 39a on the main body side, and the toner supply port is closed when both openings are displaced. A receiving portion 93 into which a protrusion provided on the slide plate 95 of the shutter mechanism on the toner cartridge side is fitted is formed at the rear side (obliquely upper left in FIG. 3) end portion of the slide plate 91.

  As shown in FIG. 5, guide members 22 and 23 made of a member having excellent slidability such as Mylar (trade name) film are attached to the upper and lower sides of the shutter mounting portion. As can be seen from FIG. 3, the shutter mounting portion is formed in a concave shape on the inner side surface of the unit. The shutter mechanism 90 is fitted into the recessed portion, and the upper and lower portions of the shutter mechanism 90 are guided by the guide members 22 and 23. As a result, the shutter mechanism 90 can move in the direction of the arrow at the shutter mounting portion.

  FIG. 6 is a schematic view showing a state in which the shutter mechanism provided in the toner cartridge 37 is disassembled. The toner cartridge 37 has a side surface on one side of the toner cartridge 37 so as to correspond to the toner replenishing port 39a of the first developing unit 35 (facing the first developing unit 35 when the toner cartridge 37 is set in the developing device 31). Toner replenishing port 39b is provided on the surface to be treated. The toner replenishing port 39b is composed of the same number of openings as the toner replenishing port 39a on the main body side of the developing device 31, and the shape and position thereof are provided so as to coincide with the toner replenishing port 39a on the main body side.

  The shutter mechanism 100 of the toner cartridge 37 includes an elastic member 94 attached to the side surface of the cartridge so as to cover the periphery of the toner supply port 39b, a slide plate 95 supported slidably outside the elastic member 94, It is composed of a fixed seal 96 disposed further outside the slide plate 95.

  The elastic member 94 is provided with a plurality of openings 94a corresponding to the toner supply ports 39b, and the number, shape, and position of the openings are provided so as to coincide with the toner supply ports 39b. The slide plate 95 is provided with a plurality of openings 95a corresponding to the toner supply port 39b and the openings 94a of the elastic member 94. The opening 95a of the slide plate 95 is also provided so that the number, shape, and position of the openings coincide with the toner supply port 39b and the opening 94a of the elastic member 94.

  The fixed seal 96 is a rigid member. The fixed seal 96 is fixed to the toner cartridge 37 and remains fixed even when the slide plate 95 moves. The fixed seal 96 is provided with a plurality of openings 96a corresponding to the toner supply port 39b, the openings 94a of the elastic member 94, and the openings 95a of the slide plate 95. The openings 96a are also provided so that the number, shape, and position of the openings coincide with the toner supply port 39b, the opening 94a of the elastic member 94, and the opening 95a of the slide plate 95.

  The slide plate 95 of the shutter mechanism 100 slides and its opening 95a coincides with the toner supply port 39b of the cartridge, the opening 94a of the elastic member 94, and the opening 96a of the fixed seal 96, whereby the toner supply port of the toner cartridge 37 is opened. In addition, the toner replenishing port is closed by shifting both the openings (opening 95a, toner replenishing port 39b, opening 94a, and opening 96a).

  Further, a projection 95b is formed at one end of the slide plate 95 (the end on the back side when the toner cartridge 37 is inserted into the developing device 31). When the toner cartridge 37 is set in the developing device 31, the protruding portion 95 b is fitted into a receiving portion 93 provided on the slide plate 91 of the shutter mechanism 90 on the developing device 31 body side.

  A locking portion 95c is formed at the end of the slide plate 95 on the side opposite to the protruding portion 95b. As shown in FIG. 4, when the slide plate 95 is supported so as to be slidable on the side surface of the cartridge, the movement range of the slide plate 95 is the locking portion 95c (opening) on the front side in the cartridge insertion direction (arrow S direction). The upper and lower oblique sides (which are formed wider than the intermediate portion provided with 95a) are restricted by contacting the upper and lower contact portions 37a and 37a provided on the cartridge 37. On the rear side in the cartridge insertion direction, the rear end portion of the locking portion 95c is regulated by coming into contact with a protrusion 97 (FIG. 6) provided on the cartridge 37.

  When the slide plate 95 moves to the maximum front side with respect to the cartridge 37, that is, when the protrusion 95 b protrudes most from the cartridge 37, the opening 95 a of the slide plate 95 is the toner supply port 39 b and the opening 94 a of the elastic member 94. In addition, the shutter mechanism 100 is closed because it does not coincide with the opening 96a of the fixed seal 96 (the opening 95a is shifted from the other openings).

  On the other hand, when the slide plate 95 is moved to the maximum rear side with respect to the cartridge 37, that is, when the rear end portion of the locking portion 95c comes into contact with the protrusion 97, the opening 95a of the slide plate 95 is a toner supply port. 39b and the opening 94a of the elastic member 94 and the opening 96a of the fixed seal 96 coincide with the opening 96a, and the shutter mechanism 100 is opened.

  The slide plate 95 is attached to the cartridge from the outside of the elastic member 94, and the slide plate 95 presses the elastic member 94 to elastically deform it, eliminating a gap between the slide plate 95 and the elastic member 94, and dropping the toner from the toner cartridge 37. To prevent. Further, since the fixed seal 96 is provided outside the slide plate 95, the opening 95a of the slide plate 95 and the opening 96a of the fixed seal 96 are displaced when the shutter mechanism 100 is closed, so that the opening 95a of the slide plate 95 is also fixed. The toner 96 that is blocked by the seal 96 (non-opening portion thereof) and remains in the opening 95a portion of the slide plate 95 is also prevented. Therefore, in the toner cartridge 37 of this example, when the cartridge is removed from the main body of the developing device 31, the toner from the cartridge is strictly prevented by the shutter mechanism 100.

  Although a detailed description of the operation of the shutter mechanism when the toner cartridge 37 is set to and removed from the developing device 31 main body is omitted, in this example, the toner cartridge 37 is set to the developing device 31 main body (developing first unit 35). As a result, the shutter mechanism 90 and the shutter mechanism 100 are automatically opened, and the toner supply port 39a on the main body side and the toner supply port 39b on the cartridge side communicate with each other. Further, when the toner cartridge 37 is removed from the main body of the developing device 31, the shutter plate 90 and the slide plate 91 and the slide plate 95 of the shutter mechanism 100 are moved in the direction opposite to the insertion direction by the operation of pulling out the cartridge 37 from the main body. The mechanism 90 and the shutter mechanism 100 are automatically closed.

  In a state where the toner cartridge 37 is set in the main body of the developing device 31, the elastic member 92 of the shutter mechanism 90 on the main body side is pressed and elastically deformed by the shutter mechanism 100 on the toner cartridge side, and a gap is formed between the fixed seal 96 and the elastic member 92. Is prevented, toner leakage at the joint portion between the toner cartridge 37 and the developing device 31 main body is prevented, and toner drop from the developing portion is prevented.

  Further, in this example, the toner mechanism 37 and the shutter mechanism 100 are automatically closed by pulling out the toner cartridge 37 from the main body of the developing device 31. Therefore, the main body of the developing device 31 (developing first unit 35) and the toner cartridge are closed. Toner leakage from 37 is prevented.

  In this example, the toner replenishing ports 39a and 39b are provided corresponding to almost the entire image forming width, so that new toner supplied from the toner cartridge 37 is imaged in the developing first unit 35 of the developing device 31 main body. Since the new toner and the toner in the first developing unit 35 are mixed appropriately because the width is mixed over almost the entire width, it is possible to effectively prevent the occurrence of image unevenness and background contamination.

  A guide rib 41 is provided in the cartridge setting section 40 of the first developing unit 35 in which the toner cartridge 37 is set. Correspondingly, a guide groove 43 that can be fitted to the guide rib 41 is formed on the bottom surface of the toner cartridge 37.

  As shown in FIGS. 3 and 5, a recess 42 is formed in the front portion of the shutter mounting portion (the portion where the shutter mechanism 90 is mounted and supported) of the developing device main body 31 (developing first unit 35). As shown in FIG. 7, the concave portion 42 is provided by partially denting the bottom surface 44 of the cartridge setting portion 40 of the developing device main body 31. When the toner clogged in the holes (openings) of the elastic members 92 and 94 of the shutter mechanisms 90 and 100 leaks from the shutter mechanism due to an impact when the cartridge is attached / detached, the dropped toner is provided in front of the shutter mounting portion. It falls into the recess 42 and is accommodated in the recess. The dropped toner accommodated in the recess 42 is not transported to the outside of the recess 42 by the attaching / detaching operation of the toner cartridge 37 to / from the cartridge setting unit 40, and the toner is prevented from leaking to the outside of the developing device. Reference numeral 45 denotes a reinforcing rib.

  Further, as shown in FIG. 8, a front portion of the shutter mounting portion is provided as a through hole 46, and the through hole 46 is formed by a thin closing member 47 such as a Mylar (trade name) film bonded to the lower surface of the developing device body 31. A closed configuration may be used. According to this configuration, the storage space for falling toner is increased, and toner leakage can be prevented for a longer period.

  By the way, as shown in FIGS. 7 and 8, the strength of the bottom surface 44 can be increased by providing a reinforcing rib 45 on the bottom surface 44 of the cartridge set portion 40 of the developing device main body 31. Reinforcing ribs cannot be provided in the recess 42 or the through hole 46. Therefore, as shown in FIG. 9, the falling toner receiving portion is constituted by a plurality of concave portions 48, whereby the boundary portions 49 between the concave portions and the concave portions serve as reinforcing ribs. Strength can be increased. In addition, it is good also as a structure (structure corresponding to FIG. 8) which makes each recessed part 48 of FIG. 9 a through-hole, and closes the bottom part with a Mylar (brand name) etc.

  FIG. 10 is a configuration example showing still another example of the falling toner receiving portion. In this figure, two concave portions 50 and 50 extending in the shutter moving direction are provided as falling toner receiving portions, and a boundary portion 51 between the two functions as a reinforcing rib. In this configuration, since the boundary portion 51 extends in the attaching / detaching direction of the toner cartridge 37, when the cartridge is attached / detached, the bottom surface portion of the cartridge does not enter the concave portion 50 of the falling toner receiving portion, and attachment / detachment workability is improved. There is no loss. In addition, it is good also as a structure which provides the recessed parts 50 and 50 as a through-hole, and closes the bottom part with a mylar (brand name) etc.

  Further, as shown in FIGS. 11 and 12, it is preferable that a seal member 52 or 53 is attached to the exit side (exit side when the toner cartridge 37 is removed) end of the recess 42 which is a falling toner receiving portion. The seal member 52 is an elastic member such as a sponge, and the seal member 53 is a flocking seal. The seal members 52 and 53 are mounted such that the upper ends thereof protrude upward from the upper ends of the recesses 42 (into the toner cartridge setting unit 40) by an appropriate amount. As described above, the seal member 52 or 53 is attached to the outlet side end portion of the concave portion 42 that is the falling toner receiving portion, so that even when the toner dropped in the concave portion 42 adheres to the bottom surface of the toner cartridge 37, the cartridge is removed when the cartridge is removed. The bottom surface is wiped off by the seal member 52 or 53, and the toner adhering to the bottom surface of the cartridge is prevented from leaking out of the developing device. In the case of the sealing member 53 by the flocking seal, each fiber is wiped off following the shape of the back surface of the toner cartridge 37, so that the wiping property is more excellent.

  11 and 12, the falling toner receiving portion has been described with the concave portion 42 in FIGS. 5 and 7. However, the falling toner receiving portion is also dropped in the through hole 46 in FIG. 8, the concave portion 50 in FIG. By attaching the seal member 52 or 53 to the outlet side end of the toner receiving portion, the same effect of preventing toner leakage can be obtained. As shown in FIG. 9, when the falling toner receiving portion is constituted by a plurality of concave portions 48 (or through holes), the sealing member 52 or 53 may be attached to the falling toner receiving portion located at the most outlet side end portion.

  Finally, the overall configuration and operation of the color copying apparatus 1 shown in FIG. 1 will be described. In the color copying apparatus 1 shown in this figure, the scanner unit 3 is disposed at the top of the apparatus, and a paper discharge unit 66 is provided in the apparatus body between the printer unit 2.

  The scanner unit 3 is provided with scanning means below the contact glass so as to be able to travel. The scanner unit 3 guides reflected light from the original illuminated by the light source to the CCD via a mirror lens or the like, and reads the original image. .

  The printer unit 2 includes a photosensitive belt unit 10, a writing optical unit 4, a developing unit 30, an intermediate transfer unit 20, a secondary transfer unit 60, a fixing unit 70, and the like. Then, black: black (hereinafter referred to as “Bk”), Cyan: cyan (hereinafter referred to as “C”), magenta: magenta (hereinafter referred to as “M”), yellow: yellow (hereinafter referred to as “Y”) are displayed on the photosensitive unit 10. The image is successively visualized on the photosensitive belt 11, and these are superposed to form a final four-color full-color image.

  The photosensitive belt 11 rotates in the clockwise direction in the figure, and around the photosensitive belt cleaning device 12, the charging roller 13, the photosensitive drum waste toner tank 17, the selected developing device of the developing unit 30, and the intermediate transfer unit 20. The intermediate transfer belt 21 is disposed. As shown in FIG. 2, the photosensitive belt 11 is stretched between a driving roller 14, a primary transfer counter roller 15, and a stretching roller 16, and is rotated by a driving motor (not shown). When the photosensitive belt 11 having a joint is used, a joint mark is provided in a non-image forming area at the end of the photosensitive belt 11 and detection is performed by a sensor (not shown) to perform image formation while avoiding the joint.

  The writing optical unit 4 converts color image data into an optical signal, performs optical writing corresponding to each color image, and forms an electrostatic latent image on the photosensitive belt 11. The writing optical unit 4 includes a semiconductor laser as a light source, a laser light emission drive control unit, a polygon mirror, a reflection mirror, and the like.

  Further, the developing unit 30 moves the developing devices 31B, 31Y, 31C, 31C, 31M, 31M, and 31M in the horizontal direction in FIG. It is comprised by the contact-and-separation mechanism etc. which are not shown in figure which perform. In the illustrated example, a Bk developing unit 31K containing black toner, a Y developing unit 31Y containing yellow toner, a C developing unit 31C containing cyan toner, and an M developing unit 31M containing magenta toner, in order from the upper side of the apparatus main body. It has become. Each developing unit 31K, Y, C, and M pumps up the developing sleeves 32K, Y, C, and M that rotate while carrying the toner on the surface in order to develop the electrostatic latent image on the surface of the photoreceptor belt 11. Development first units 35K, Y, C, and M including toner paddles 33K, Y, C, and M that rotate to stir and development second units of toner cartridges 34K, Y, C, and M that contain toner It consists of two units.

  The toner in each developing device 31K, Y, C, M is charged to a predetermined polarity, and a developing bias is applied to each developing sleeve 32K, Y, C, M by a developing bias power source (not shown), and the developing sleeve 32K, Y, C, and M are biased to a predetermined potential with respect to the photosensitive belt 11. In addition, when the electromagnetic clutch (not shown) for transmitting the drive from the motor (not shown) to each developing device 31K, Y, C, M is turned on, the contact / separation mechanism is driven by the driving force of each developing device 31K, Y, C, M is moved to the photosensitive belt 11 side (right side in the figure). At the time of development, any one selected from the developing devices 31K, Y, C, and M moves and contacts the photosensitive belt 11. On the other hand, when the electromagnetic clutch is turned off and the drive transmission is released, the developing unit that is in contact with the photosensitive belt 11 moves in a direction away from the photosensitive belt 11 (left side in the figure).

  In the standby state of the main body of the color copying apparatus, the developing unit 30 is set at a position separated from the photosensitive belt 11 in any of the developing units 31K, Y, C, and M, and when the printing operation is started, the scanner unit 3 Based on the image data read in step 1 or image data from an external device such as a personal computer, optical writing with a laser beam and formation of an electrostatic latent image are started.

  The intermediate transfer unit 20 includes an intermediate transfer belt 21, a belt cleaning device 22, a position detection sensor, and the like. The intermediate transfer belt 21 is stretched around a drive roller, a primary transfer roller, a secondary transfer counter roller 26, a cleaning counter roller, and a tension roller, and is driven and controlled in a counterclockwise direction in the drawing by a drive motor (not shown).

  In addition, transfer paper is stored in the transfer paper cassettes 80 a and 80 b of the color printer 1, sent out by a paper feed roller 81, and conveyed to a registration roller 83 via a conveyance roller 82.

  Further, the secondary transfer unit 60 includes a secondary transfer roller 61 and a swinging mechanism (not shown) including a clutch for bringing the secondary transfer roller 61 into and out of contact with the intermediate transfer belt 21. ing. The secondary transfer roller 61 swings about the rotation axis of the swing mechanism in accordance with the timing when the transfer paper reaches the transfer position. The secondary transfer roller 61 and the secondary transfer counter roller 26 bring the transfer paper and the intermediate transfer belt 21 into contact with each other at a constant pressure. The secondary transfer roller 61 maintains the positional accuracy of the parallelism with the secondary transfer counter roller 26 by a positioning member (not shown) provided in the intermediate transfer unit 20. Further, the contact pressure of the secondary transfer roller 61 with respect to the intermediate transfer belt 21 is made constant by a positioning roller (not shown) provided on the secondary transfer roller 61. At the same time when the secondary transfer roller 61 is brought into contact with the intermediate transfer belt 21, a transfer bias having a polarity opposite to that of the toner is applied to the secondary transfer roller 61, and the superimposed toner images on the intermediate transfer belt 21 are collectively transferred onto the transfer paper.

  Each unit can be easily detached from the apparatus. For example, in FIG. 1, when the intermediate transfer unit 20 is removed, it can be easily removed by opening a front cover (not shown) and sliding the unit from the back side to the front side of the paper.

  In the color copying apparatus 1 configured as described above, when the image forming cycle is started, first, the photosensitive belt 11 is rotated clockwise in the figure and the intermediate transfer belt 21 is rotated counterclockwise in the figure by a drive motor (not shown). M toner image formation, C toner image formation, Y toner image formation, and Bk toner image formation are performed on the photosensitive belt 11, and finally the toner is superimposed on the intermediate transfer belt 21 in the order of M, C, Y, and Bk. An image is formed. At this time, the bias applied to the primary transfer roller 25 generally increases the voltage sequentially, but differs depending on the resistance characteristics of the intermediate transfer belt 21 and the like.

  The M toner image formation is performed as follows. The charging roller 13 uniformly charges the photosensitive belt 11 by an applied voltage of a power source (not shown). Then, the laser beam LD for writing is exposed based on the M color image signal. When this exposure is performed, the charge proportional to the exposure light amount disappears in the exposed portion of the photosensitive belt 11 that is initially uniformly charged, and an M electrostatic latent image is formed. Then, when the M toner on the M developing sleeve 32M comes into contact with the M electrostatic latent image, the toner does not adhere to the remaining portion of the photosensitive belt 11, and the exposed portion, that is, the exposed portion is exposed. M toner is attracted to the portion, and an M toner image similar to the electrostatic latent image is formed. The M toner image formed on the photoreceptor belt 11 contacts the intermediate transfer belt 21 at the primary transfer position. At the primary transfer position, a nip is formed between the intermediate transfer belt 21 and the photosensitive belt 11 by the primary transfer roller and the counter roller 15, and a bias having a polarity opposite to that of the M toner image is applied to the primary transfer roller. Is applied to transfer the M toner image to the intermediate transfer belt 21.

  Some untransferred residual toner on the photoreceptor belt 11 is cleaned by the photoreceptor cleaning device 12 in preparation for reuse of the photoreceptor belt 11. The toner collected here is stored in the waste toner tank 17 via a collection pipe.

  On the photosensitive belt 11 side, the process proceeds to the C image forming process after the M image forming process, and writing with the laser light LD by the C image data is performed to form a C electrostatic latent image. Then, after the rear end portion of the previous M electrostatic latent image has passed and before the front end portion of the C electrostatic latent image has arrived, the M developing device is retracted from the developing position, and the C developing device C is moved to the developing position. The C electrostatic latent image is developed with C toner. Thereafter, the development of the C electrostatic latent image area is continued, but when the rear end of the C electrostatic latent image passes, the C developer is retracted from the development position as in the case of the previous M developer. Then, the next Y developing device is moved to the developing position. This is also completed before the leading edge of the next Bk electrostatic latent image reaches the developing position. The Y and Bk image forming steps are the same as the above-described M and C steps, respectively, because the electrostatic latent image forming and developing operations are the same as those described above.

  On the intermediate transfer belt 21, toner images of M, C, Y, and Bk that are sequentially formed on the photosensitive belt 11 are sequentially aligned on the same surface to form a four-color superimposed toner image. In the next transfer step, the toner images of these four colors are collectively transferred onto the transfer paper.

  At the time when the image forming operation is started, the transfer paper is fed from one of the transfer paper cassettes 80 a and 80 b and is waiting at the nip of the registration roller 83. Then, when the leading edge of the four-color superimposed toner image on the intermediate transfer belt 21 approaches the secondary transfer roller 61, the registration roller pair 83 is driven so that the leading edge of the transfer paper coincides with the leading edge of the toner image. The transfer paper and the toner image are aligned. Then, the transfer paper is superimposed on the toner image on the intermediate transfer belt 21 and passes through the secondary transfer position. At this time, the transfer paper is charged by the transfer bias by the secondary transfer roller 61, and most of the toner image is transferred onto the transfer paper.

  Then, the transfer paper onto which the four-color superimposed toner images are collectively transferred from the intermediate transfer belt 21 is conveyed to the fixing unit 70, and the toner image is melted and fixed at the nip portion between the fixing belt and the pressure roller controlled to a predetermined temperature. The paper is discharged to the in-body paper discharge unit 66 and stacked face down on the paper discharge tray 67 to obtain a full color copy.

  On the other hand, the surface of the photoreceptor belt 11 after the primary transfer is cleaned by the photoreceptor cleaning device 12 and is uniformly neutralized by a neutralization lamp (not shown). Further, the surface of the intermediate transfer belt 21 after the toner image is transferred onto the transfer paper is cleaned by pressing the cleaning brush of the belt cleaning device 22 with the contact / separation mechanism. The toner cleaned from the intermediate transfer belt 21 is stored in a waste toner tank 29.

As mentioned above, although this invention was demonstrated by the example of illustration, this invention is not limited to this.
For example, the position, size, shape, number, etc., of the recesses and through-holes (those whose bottoms are closed) as falling toner receiving parts can be changed according to the shape and configuration of the developing device main body and the toner cartridge. is there. Moreover, the depth of the recess and the through hole is also arbitrary.

  Furthermore, the configuration of each part of the image forming apparatus is also arbitrary. Needless to say, the present invention can also be applied to a monochrome apparatus having a single developing unit. The image forming apparatus is not limited to a copying apparatus, but may be a printer, a facsimile machine, or a multi-function machine having a plurality of functions.

1 is a cross-sectional view illustrating a schematic configuration of a color copying apparatus which is an example of an image forming apparatus to which the present invention is applied. FIG. 2 is an enlarged view showing a developing unit and a photosensitive belt unit of the color copying apparatus. FIG. 4 is a perspective view showing the developing device with the toner cartridge removed. FIG. 3 is a perspective view of a toner cartridge. FIG. 6 is a partial perspective view showing a shutter mounting portion of the developing device main body. FIG. 4 is a schematic diagram illustrating a state where a shutter mechanism of the toner cartridge is disassembled. 2 is a partial cross-sectional view of a developing device main body. FIG. 6 is a partial cross-sectional view of a developing device main body provided with a through hole as a falling toner receiver. FIG. 10 is a partial perspective view illustrating another example of a falling toner receiving portion provided in the developing device main body. FIG. 12 is a partial perspective view showing still another example of a falling toner receiving portion provided in the developing device main body. FIG. 10 is a partial perspective view illustrating a configuration example in which a sealing member is provided in a falling toner receiving portion. FIG. 6 is a partial perspective view illustrating a configuration example in which a different toner seal member is provided in a falling toner receiving portion. It is a perspective view which shows the developing device main body in an example of the conventional developing device. FIG. 10 is a perspective view of a toner cartridge in an example of a conventional developing device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Color copying apparatus 30 Developing unit 31 Developing device main body 35 Developing first unit 37 Toner cartridge (developing second unit)
39a Developer toner replenishment port 39b Toner cartridge toner replenishment port 40 Cartridge set part 42, 50 Recess (falling toner receiving part)
46 Through hole (falling toner receiving part)
47 Closing member 48 Multiple recesses (falling toner receiver)
49,51 boundary (reinforcing rib)
52 Sealing member (elastic member)
53 Seal member (flocking member)
90, 100 Shutter mechanism 92, 94 Elastic member

Claims (8)

A developing device that removably provides a toner cartridge to the developing device main body and replenishes toner from a toner replenishing port provided in the toner cartridge through a toner replenishing port provided in the developing device main body,
In the developing device having a shutter mechanism in each of the toner replenishing port of the toner cartridge and the toner replenishing port of the developing device main body,
A toner receiving portion for receiving and storing the dropped toner at a lower position of the shutter mechanism of the developing device body;
The toner receiving portion comprises a plurality of receiving portions,
A developing device, wherein a seal member that is in sliding contact with a bottom surface of the toner cartridge is provided at a receiving portion located at an end portion on the toner cartridge outlet side among the toner receiving portions including the plurality of receiving portions. The developing device according to claim 1, wherein the toner receiving portion is formed as a concave portion in which a part of a unit case of the developing device main body is recessed. The developing device according to claim 1, wherein the toner receiving portion is formed by closing a bottom portion of a through hole provided through a part of a unit case of the developing device main body with another member. The developing device according to claim 1 , wherein the seal member is an elastic member. The developing device according to claim 1 , wherein the seal member is a flocking member. The developing device according to claim 1, wherein the shutter mechanism of the developing device main body has an elastic member disposed on the outermost side. The developing device according to claim 6 , wherein the shutter mechanism of the toner cartridge has a sheet-like member having excellent slidability disposed on the outermost side. An image forming apparatus comprising: a developing device according to any one of claims 1-7.

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