JP6079189B2 - Development device - Google Patents

Description

  The present invention relates to a developing device including a developing roller.

  2. Description of the Related Art Conventionally, there has been known a developing device including a housing having a developer storage chamber and having an opening and a developing roller provided so as to face the opening.

  In such a developing device, it is necessary to suppress toner leakage from the gap between the lower side of the developing roller and the housing.

  Thus, for example, Patent Document 1 discloses a developing device including a seal member for suppressing toner leakage from between the lower side of the developing roller and the housing (see Patent Document 1).

  Specifically, the seal member is disposed in a storage chamber in which the developing roller and the supply roller are disposed, and is formed in an elongated shape that is long in the axial direction of the developing roller. The seal member includes an elastic member attached to the housing and a sheet member supported by the elastic member and in contact with the developing roller.

JP-A-11-265119

  However, the conventional configuration has the following problems.

  The developing device may be accidentally dropped during, for example, attachment / detachment work with respect to the image forming apparatus or shipping / shipping of the developing device. In such a case, when the developing device falls from the side surface side of the housing, the developer in the storage chamber is biased toward the side surface side downstream in the gravity direction due to gravity.

  Further, when the developing device comes into contact with the floor surface or the like, the elastic member and the housing are bent by the impact, so that a slight gap may be formed between the developing roller and the elastic member. At this time, since the developer is biased toward the side surface of the housing, the developer may enter the gap. As described above, if the developer enters the gap widened by the impact, the developer in the gap is pressed by the elastic member when the elastic member tries to return to the original shape, and the pressing force There is a possibility that a problem such as leakage from the developing cartridge may occur.

  Accordingly, an object of the present invention is to provide a developing device capable of suppressing the leakage of the developer even when the developing device is accidentally dropped.

In order to achieve the above object, a developing device of the present invention includes a frame having a developer accommodating portion configured to accommodate a developer, and a developing roller that is rotatable about a rotation axis with respect to the frame. , A supply roller configured to contact the developing roller and supply the developer to the developing roller, and the developer roller is disposed between the developing roller and the frame. A seal for suppressing leakage, and a first film that is disposed between the seal and the supply roller in an orthogonal direction orthogonal to the rotation axis and is in contact with the peripheral surface of the supply roller.

  According to such a configuration, the first film regulates the developer that is biased toward the side surface of the frame as it is dropped so as not to move toward the seal.

  Therefore, it is possible to suppress the developer from entering the gap between the seal and the developing roller.

As a result, even if the developing device is accidentally dropped, the developer can be prevented from leaking. Further, the frame is a wall disposed downstream of the seal in the rotation direction of the developing roller. The wall includes a first surface that comes into contact with the seal, and a second surface closer to the developer accommodating portion than the first surface, and the first film may be disposed on the second surface.

  According to such a structure, when attaching a 1st film, a seal | sticker does not become obstructive.

  As a result, the first film can be easily attached.

  The frame extends in a crossing direction intersecting with the rotation axis and the orthogonal direction, and has a guide groove for guiding the developing roller. The seal has a first film in the mounting direction in which the developing roller is mounted on the frame. It may be arranged on the upstream side in the mounting direction.

  According to such a configuration, when the developing roller is mounted on the frame, the developing roller can be reliably brought into contact with the seal, and the developer can be prevented from leaking from between the developing roller and the seal. .

  As a result, the developer can be further prevented from leaking from the developing device.

  Further, the first film may protrude toward the guide groove rather than the seal when the developing roller is not attached to the frame.

According to such a configuration, when the developing roller is mounted on the frame, when the seal is elastically deformed downstream in the mounting direction, the tip of the first film does not contact the elastically deformed seal portion. In other words, the leading edge of the first film does not pierce the elastically deformed portion of the first seal. As a result, the developer can be further prevented from leaking from the developing device.

  Further, the first film may contact the developing roller.

  According to such a configuration, the space formed by the supply roller, the developing roller, and the frame can be further narrowed.

  As a result, the first film can suppress the developer from entering the gap between the seal and the developing roller.

  Moreover, the 1st film may have the one side film arrange | positioned at the one side in a rotating shaft line, and the other side film arrange | positioned at the other side in a rotating shaft line.

  According to such a configuration, the one side film can be arranged on the basis of one side and the other side film can be arranged on the basis of the other side, and the first film is formed in one long shape. In comparison, the positioning accuracy for arranging the first film can be improved.

  As a result, the developer can be further prevented from leaking from the developing device.

  The seal may include a second film that contacts the developing roller, and a sponge that presses the second film toward the developing roller.

  According to such a configuration, the second film can be reliably pressed toward the developing roller by the sponge.

  As a result, the developer can be further prevented from leaking from the developing device.

  Further, the seal may be held by being sandwiched between the developing roller and the frame.

  With such a configuration, the seal can be attached to the frame simply by sandwiching the seal between the developing roller and the frame.

  As a result, the seal can be easily attached to the frame without using double-sided tape.

  The first film may be urethane rubber.

  With such a configuration, it is possible to suppress contamination of the developing roller even when it is in contact with the developing roller for a long time.

  According to the developing device of the present invention, it is possible to prevent the developer from leaking even when the developing device is accidentally dropped.

FIG. 3 is a perspective view of an embodiment of the developing cartridge as viewed from the upper right side. FIG. 2 is a perspective view of a state where a developing roller, a supply roller, and a lower seal of the developing cartridge shown in FIG. FIG. 2 is a side sectional view of the developing cartridge shown in FIG. 1. FIG. 4 is an enlarged view of a main part in a state where a developing roller of the developing cartridge shown in FIG. FIG. 4 is an explanatory diagram for explaining a state where the developer cartridge shown in FIG. 3 is dropped from the right side surface thereof.

1. Configuration of Developing Cartridge A developing cartridge 1 as an example of a developing device is configured to be detachable from an image forming apparatus (not shown) such as a laser printer. The image forming apparatus includes a photosensitive member such as a photosensitive drum on which an electrostatic latent image is formed, and the developing cartridge 1 supplies a developer to the electrostatic latent image formed on the photosensitive drum, thereby developing the electrostatic latent image. Develop. The image forming apparatus transfers a developed electrostatic latent image, specifically, a toner image from a photosensitive drum to a sheet, and then fixes the image to form an image on the sheet.

  As shown in FIG. 1, the developing cartridge 1 includes a developing frame 2 as an example of a frame. The development frame 2 is formed in a substantially box shape, and an opening is formed along the longitudinal direction (left-right direction).

  In addition, when referring to the direction with respect to the developing cartridge 1, the direction when it is placed in the horizontal direction is used as a reference, and specifically, the direction of the arrow shown in each drawing is used as a reference. Specifically, the side on which the opening is formed is the rear side, the opposite side is the front side, and the front-rear direction is an example of the orthogonal direction. Also, the left and right reference is when the developing cartridge 1 is viewed from the front side.

(1) Development Frame The development frame 2 is composed of an upper frame 3 and a lower frame 4 as shown in FIG.

  The upper frame 3 is formed in a substantially flat plate shape that is substantially rectangular in plan view and extends in the left-right direction. The upper frame 3 has a blade support portion that supports the layer thickness regulating blade 93 on the rear side.

  As shown in FIGS. 1 and 3, the lower frame 4 is formed in a substantially flat plate shape that is substantially rectangular in a bottom view extending in the left-right direction. The lower frame 4 includes a pair of side walls 41, a front wall 44, and a lower wall 5.

  The pair of side walls 41 includes a support portion 42 that supports the developing roller 91.

  As shown in FIGS. 2 and 4, the support portion 42 supports both ends of the developing roller shaft 91 a of the developing roller 91 via bearings (not shown). Moreover, the support part 42 has the guide groove 43 as an example of a guide groove.

  The guide groove 43 is formed on the rear side of the support portion 42, extends in the rear upper direction intersecting with the left-right direction, and is formed in a substantially U shape in side view that opens to the rear upper side.

  As a result, the rotation shaft of the developing roller 91 is inserted from the outside of the developing frame 2 along the guide groove 43 in the front and lower direction as an example of the mounting direction and the crossing direction. The support part 42 is guided from the outside of the frame 2.

  The front wall 44 is continuous from the front end portion of the lower wall 5 and is integrally constructed between the front end portions of the pair of side walls 41.

  The lower wall 5 is formed in a substantially flat plate shape extending in the left-right direction, as shown in FIG. The lower wall 5 includes a partition wall 6 and a lower seal installation groove 7.

  The partition wall 6 is formed integrally with the lower wall 5 at a substantially central portion in the front-rear direction of the lower wall 5. Further, the lower wall 5 is integrally constructed between the lower ends of the pair of side walls 41. Further, the lower wall 5 is integrally formed with a lower seal installation groove 7 on the rear side of the partition wall 6.

  The lower seal installation groove 7 includes a bottom wall 71, a first wall 72 as an example of a wall, and a second wall 73.

  The bottom wall 71 is formed in a substantially flat plate shape having a substantially rectangular shape in a side sectional view extending rearward.

The first wall 72 is formed in a substantially flat plate shape that is substantially rectangular in a side sectional view and protrudes upward so as to be substantially perpendicular to the bottom wall 71. Further, the first wall 72 is disposed downstream of the lower seal 94 described later in the rotation direction of the developing roller 91 (clockwise direction in FIG. 3).

  More specifically, the first wall 72 protrudes upward by 1.5 mm from the bottom wall 71. Further, the first wall 72 has a contact surface 72 a on the front side of the first wall 72, which is in contact with a lower seal 94 as an example of the first surface. A pasting surface 72b is formed on the rear side of the first wall 72 to which a regulation film 95 described later as an example of the second surface is pasted.

  The second wall 73 is formed in a substantially flat plate shape that is substantially rectangular in a side sectional view and extends upward from the bottom wall 71 so as to be substantially perpendicular to the bottom wall 71.

  Further, when the upper frame 3 and the lower frame 4 are combined in the developing frame 2, a toner containing chamber 8 as an example of a developer containing portion that contains toner is divided in front of the dividing wall 6, and the dividing wall is divided. On the rear side of FIG. 6, the developing chamber 9 is defined. Further, on the rear side of the toner storage chamber 8, a communication port that connects the toner storage chamber 8 and the development chamber 9 is formed.

(2) Toner Storage Chamber The toner storage chamber 8 stores toner as an example of a developer, and is provided with an agitator 81. The agitator 81 is rotatably supported by a pair of side walls 41 corresponding to the toner storage chamber 8.

(3) Developing chamber The developing chamber 9 is provided with a developing roller 91, a supply roller 92, a layer thickness regulating member 93, a lower seal 94 as an example of a seal, and a regulating film 95 as an example of a first film. It has been.

(3-1) Developing Roller The developing roller 91 includes a developing roller shaft 91a and a rubber roller 91b.

  The developing roller shaft 91a is made of metal and has a substantially cylindrical shape extending in the left-right direction.

  The rubber roller 91b covers the developing roller shaft 91a so as to expose each of the left end portion and the right end portion of the developing roller shaft 91a.

  The developing roller shaft 91 a is supported by the support 42 so that the developing roller 91 is centered on the developing roller shaft 91 a with respect to the developing frame 2.

(3-2) Supply Roller The supply roller 92 includes a supply roller shaft 92a and a sponge roller 92b.

  The supply roller shaft 92a is formed in a substantially cylindrical shape extending in the left-right direction.

  The sponge roller 92b covers the supply roller shaft 92a so that the left and right ends of the supply roller shaft 92a are exposed.

The supply roller 92 is disposed so that the sponge roller 92b is in pressure contact with the rubber roller 91b of the developing roller 91, and both ends of the supply roller shaft 92a pass through the pair of side walls 41, and a supply roller shaft 92a (not shown) is provided. It is supported by the developing frame 2 by being rotatably supported in the support hole.

(3-3) Layer Thickness Restricting Member The layer thickness restricting member 93 is supported by the developing frame 2 so that the plate-shaped blade contacts the rubber roller 91b of the developing roller 91 from above.

(3-4) Lower Seal The lower seal 94 is a member that suppresses toner leakage from between the lower side of the outer peripheral surface of the developing roller 91 and the lower frame 4. The lower seal 94 is composed of a base 94b made of urethane sponge and a film 94a that is provided on the surface of the base 94b on the developing roller side and contacts the outer peripheral surface of the developing roller 91. The lower seal 94 is held between the developing roller 91 and the lower frame 4 of the developing frame 2 in a state where the lower seal 94 is simply placed in the lower seal installation groove 7 without using a double-sided tape or the like.

  More specifically, after the lower seal 94 is placed in the lower seal installation groove 7, the developing roller 91 is assembled to the lower frame 4 of the developing frame 2 so that the lower seal 94 is adjacent to the first wall 72. 91 and the lower frame of the developing frame 2 are held.

  Further, when the developing roller 91 rotates, the lower seal 94 tends to move downstream by receiving a force from the developing roller 91 toward the downstream side in the rotational direction. However, the movement is restricted by the first wall 72. In other words, the lower seal 94 is in close contact with the first wall. As a result, the lower seal 94 is held between the developing roller 91 and the developing frame 2 without using a double-sided tape or the like.

  The base 94b is formed in a rectangular parallelepiped shape extending in the left-right direction, and is provided between the film 94a and the developing frame 2.

  More specifically, the base material 94b is configured to press the film 94a toward the developing roller 91 by compressive deformation. Further, the base 94b is, for example, a length of the base 94b in the horizontal direction of 223.9 mm to 224.7 mm and a length of the base 94b in the vertical direction before the base 94b is assembled to the development frame 2. Is 3.8 mm to 4.2 mm, and the length of the base 94b in the front-rear direction is 4.8 mm to 5.2 mm.

  The film 94a is a sheet-like member made of polyethylene terephthalate, extends along the axial direction of the developing roller 91, and is in sliding contact with substantially the entire rubber roller 91b of the developing roller 91.

(3-5) Restriction Film As shown in FIG. 2, the restriction film 95 includes a right restriction film 95 a as an example of one side film and a left restriction film 95 b as an example of the other side film.

  The right side regulation film 95a and the left side regulation film 95b are arranged at an interval in the left-right direction.

  In addition, since the left side regulation film 95b and the right side regulation film 95a are the same structures, only the right side regulation film 95a is demonstrated here.

The right regulation film 95a is a sheet-like member made of urethane rubber and formed in a plate shape that is long in the left-right direction. Then, one end side of the left regulating film 95b is affixed to the affixing surface 72b on the rear side of the first wall 72 of the developing frame 2 with a double-sided tape. Further, as shown in FIG. 2, the right regulation film 95a is pasted with a space from the left regulation film 95b in the left-right direction.

  More specifically, the left regulating film 95b is, for example, such that the left regulating film 95b has a horizontal length of 99.4 mm to 100.6 mm and a vertical length of 6.7 mm to 7.9 mm. It is configured. Then, a portion of 2.7 mm to 3.3 mm from one end of the left regulating film 95b is stuck to the pasting surface 72b, and the tip of the left regulating film 95b (the other end side of the left regulating film 95b) can swing. Yes. Further, as shown in FIG. 4, in a state before the developing roller 91 is assembled to the developing frame 2, the left regulating film 95b is arranged to protrude upward by 1.8 mm from the upper surface of the film 94a of the lower seal 94. ing.

  As shown in FIG. 3, in the state where the developing roller 91 is assembled to the developing frame 2, the left regulating film 95 b bends to the rear side of the left regulating film 95 b, and the leading side is the sponge roller 92 b of the supply roller 92. The outer peripheral surface of the rear side and the lower outer peripheral surface of the rubber roller 91b of the developing roller 91 are contacted.

3. Toner movement when developer cartridge falls
Next, the movement of the toner when dropped from the right side surface of the developing cartridge 1 will be described. In the following, the case of falling from the right side surface will be described. However, when falling from the left side surface, the movement of the toner in the developing chamber 9 can be regulated by the left side regulation film 95b in the same manner as the right side regulation film 95a. it can.

  First, when the developing cartridge 1 falls from the right side surface of the developing cartridge 1, as shown in FIG. 5, the water level of the toner in the developing chamber 9 rises compared to FIG. This is because the toner on the left side of the developing chamber 9 is biased to the right side of the developing chamber 9 due to gravity.

  Thereafter, the water level T2 of the toner on the right side of the developing chamber 9 rises to the right regulating film 95a.

  On the other hand, since the leading end side of the right regulating film 95a is in contact with the sponge roller 92b of the supply roller 92 and the rubber roller 91b of the developing roller 91, the toner level T2 is prevented from further rising. In other words, the toner between the lower wall 5 of the developing frame 2 and the supply roller 92 causes the outer peripheral surface of the sponge roller 92b of the supply roller 92, the outer peripheral surface of the rubber roller 91b of the developing roller 91, and the leading end side of the left regulating film 95b. It does not enter the space S surrounded by.

  Further, when the developing cartridge 1 comes into contact with the floor surface or the like, the impact is transmitted to the pair of side walls 41, the lower wall 5, and further to the base material 94b. At this time, the base 94b is elastically deformed and the lower wall 5 is bent, so that a slight gap may be formed between the developing roller 91 and the film 94a of the lower seal 94. The biased toner is prevented from entering the gap because movement to the rear side is regulated by the right regulation film 95a.

4). Effects (1) In the developing cartridge 1, the regulation film 95 is disposed between the supply roller 92 and the lower seal 94 in the front-rear direction. Further, the leading end side of the regulating film 95 is in contact with the rear outer peripheral surface of the sponge roller 92 b of the supply roller 92.

  For this reason, the regulating film 95 regulates the toner that is biased to one side of the developing chamber 9 as it falls, so that the toner does not move toward the lower seal 94. Therefore, the toner is placed in the gap between the lower seal 94 and the developing roller 91. It can suppress entering.

  As a result, it is possible to prevent the toner from leaking out of the developing cartridge 1 even if the developing cartridge 1 is accidentally dropped.

  (2) Further, the regulating film 95 is disposed on the first wall sticking surface 72b different from the first wall contact surface 72a in the first wall disposed downstream of the lower seal 94 in the rotation direction of the developing roller 91. Has been.

  Therefore, the lower seal 94 does not get in the way when the restriction film 95 is attached.

  As a result, the restriction film 95 can be easily attached to the first wall.

  (3) The pair of side walls 41 of the developing frame 2 is formed with guide grooves 43, and the lower seal 94 is disposed upstream of the regulating film 95 in the mounting direction of the developing roller 91.

  Therefore, when the developing roller 91 is assembled to the developing frame 2, the developing roller 91 can be reliably brought into contact with the lower seal 94, and toner leakage from between the developing roller 91 and the lower seal 94 can be suppressed. .

  As a result, more toner can be prevented from leaking from the developing cartridge 1.

  (4) Moreover, the regulation film 95 protrudes upward from the film 94a of the lower seal 94.

Therefore, when the developing roller 91 is assembled to the developing frame 2, if the base 94b of the lower seal 94 is elastically deformed downstream in the mounting direction, the tip of the regulation film 95 contacts the elastically deformed part of the base 94b. do not do. In other words, the leading end of the regulation film 95 does not pierce into the elastically deformed portion of the base 94b. As a result, the regulation film 95 can be reliably brought into contact with the supply roller 92.

  (5) The regulation film 95 is also in contact with the outer peripheral surface of the rubber roller 91b of the developing roller 91.

  Therefore, the space formed by the supply roller 92, the developing roller 91, and the first wall can be further narrowed, and the toner can be prevented from entering the gap between the lower seal 94 and the developing roller 91.

  As a result, more toner can be prevented from leaking from the developing cartridge 1.

  (6) The regulation film 95 includes a right regulation film 95a and a left regulation film 95b.

  Therefore, the left regulation film 95b can be arranged on the first wall with the left side as a reference, and the right regulation film 95a can be arranged on the first wall with the right side as a reference, compared to the case where the regulation film 95 is formed in one long shape. The positioning accuracy for disposing the regulating film 95 can be improved.

  As a result, more toner can be prevented from leaking from the developing cartridge 1.

  (7) The lower seal 94 includes a film 94a and a base 94b formed of sponge.

  Therefore, the film 94a can be reliably pressed toward the developing roller 91 by the base 94b.

  As a result, more toner can be prevented from leaking from the developing cartridge 1.

  (8) Further, the lower seal 94 is sandwiched and held between the developing roller 91 and the developing frame 2.

  Therefore, the lower seal 94 can be attached to the developing frame 2 simply by sandwiching the lower seal 94 between the developing roller 91 and the lower frame 7 of the developing frame 2.

  As a result, the lower seal 94 can be easily attached to the developing frame 2 without using a double-sided tape.

  (9) Further, the regulation film 95 is made of urethane rubber.

  Therefore, even when the regulation film 95 is in contact with the developing roller 91 for a long time, it is possible to prevent the developing roller 91 from being contaminated.

5. In the above embodiment, the restriction film 95 is urethane rubber, but may be a resin such as polyethylene terephthalate.

  Even in such a configuration, it is possible to prevent the toner from leaking out of the developing cartridge even when the developing cartridge is accidentally dropped.

  In the above embodiment, the lower seal 94 has a urethane sponge, but other sponges may be used, for example.

  Even in such a configuration, it is possible to prevent the toner from leaking out of the developing cartridge even when the developing cartridge is accidentally dropped.

  Moreover, in the said embodiment, although the film 94a was polyethylene terephthalate, other resin etc. may be sufficient.

  Even in such a configuration, it is possible to prevent the toner from leaking out of the developing cartridge even when the developing cartridge is accidentally dropped.

  In the above-described embodiment, the developing cartridge that can be mounted on the image forming apparatus having the photosensitive member is illustrated. However, for example, the developing cartridge that can be mounted on the drum cartridge having the photosensitive member, the drum unit having the photosensitive member, and the developing cartridge May be an integral cartridge.

DESCRIPTION OF SYMBOLS 1 ... Development cartridge, 2 ... Development frame, 43 ... Guide groove, 7 ... Lower seal installation groove, 72 ... 1st wall, 72a ... Contact surface, 72b ... Pasting surface 8 ... Toner storage chamber, 9 ... Development chamber, 91 ... Development roller, 92 ... Supply roller, 94 ... Lower seal, 94a ... Film, 94b ... Base material, 95 ... Regulation film, 95a ... Right side regulation film, 95b ... Left side regulation film

Claims (8)

A frame having a developer accommodating portion configured to accommodate the developer;
A developing roller rotatable about a rotation axis with respect to the frame;
A supply roller configured to contact the developing roller and supply developer to the developing roller;
A seal that is disposed between the developing roller and the frame, and prevents the developer from leaking from between the developing roller and the frame due to compression deformation;
A first film disposed between the seal and the supply roller in an orthogonal direction orthogonal to the rotation axis, and in contact with a peripheral surface of the supply roller ;
It said first film is a developing device according to claim features and to Rukoto that abuts against the developing roller. The frame has a wall disposed downstream of the seal in the rotation direction of the developing roller,
The wall includes a first surface in contact with the seal, and a second surface closer to the developer accommodating portion than the first surface,
The developing device according to claim 1, wherein the first film is disposed on the second surface. The frame has a guide groove that extends in an intersecting direction intersecting the rotation axis and the orthogonal direction and is configured to guide the developing roller;
3. The seal according to claim 1, wherein the seal is disposed upstream of the first film in the mounting direction in which the developing roller is mounted on the frame in the intersecting direction. The developing device according to 1.   The developing device according to claim 3, wherein the first film protrudes toward the guide groove rather than the seal when the developing roller is not attached to the frame. The first film is the one the side film disposed on one side of the axis of rotation of claims 1 to 4, characterized in that it has a second side film disposed on the other side in the rotation axis The developing device according to any one of the above. The said seal | sticker is provided with the 2nd film which contacts the said developing roller, and the sponge for pressing a 2nd film toward the said developing roller, The any one of Claim 1 thru | or 5 characterized by the above-mentioned. The developing device according to one item. The seal is a developing device according to any one of claims 1 to 6, characterized in that it is held sandwiched between the said and the developing roller frame. The first film developing device according to any one of claims 1 to 7, characterized in that a urethane rubber.