JP2008033124A - Developing device and image forming apparatus using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To effectively remove residual toner getting into an inclined groove after development in a developing roller having the regular inclined groove. <P>SOLUTION: A groove overlap part 20c for grooves 22a and 22b formed in the different inclined directions each other is formed in the center area in a shaft direction of an all-groove forming part, and first and second inclined groove singly forming parts 20d and 20e comprising the inclined grooves 22a and 22b advancing toward either of both ends of the developing roller 20 relative to the rotating direction α of the developing roller 20 are respectively formed in both end areas of the all-groove forming part. The tips of the bristles 19b<SB>1</SB>of the brush of the toner supply ball member 19b of a toner supply roller 19 are made to reach the groove non-forming parts 20f and 20g of the developing roller 20. The toner left after development getting into the first and the second grooves 22a and 22b is effectively removed by the bristles 19b<SB>1</SB>of the brush. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a technical field of a developing device that develops an electrostatic latent image on an image carrier with toner conveyed by a developing roller, and an image forming apparatus using the same, such as a printer, an electrophotographic device, and a facsimile. The present invention relates to a technical field of a developing device including at least a developing roller having a regular inclined groove formed on an outer peripheral surface and a toner supply roller including a brush roller that supplies toner to the developing roller, and an image forming apparatus using the developing device.

  In a conventional electrophotographic image forming apparatus, in a developing device that develops an electrostatic latent image on an image carrier with nonmagnetic one-component toner, toner T is supplied by a toner supply roller a as shown in FIG. Electric charge is applied to the toner T by supplying the toner T onto the developing roller b and frictionally charging the toner T on the developing roller b (see, for example, Patent Document 1). In that case, in order to make the toner T rub well with the developing roller b, a surface having a predetermined surface roughness formed by, for example, blasting or the like is formed on the outer surface of the developing roller b. A predetermined width is formed in the direction.

  By the way, when the number of times of image formation increases, the outer peripheral surface of the developing roller b is scraped, and the surface roughness is reduced. As described above, when the surface roughness of the outer peripheral surface of the developing roller b is reduced, the friction state of the toner T by the developing roller b becomes less favorable than the initial state. For this reason, the developing roller b cannot effectively frictionally charge the toner T, and the life of the developing roller b, that is, the life of the developing device is reached. The reason why the surface of the developing roller b is shaved is that the external additive silica to be externally added to the toner base particles has a very high hardness. Therefore, in the image forming apparatus described in Patent Document 1, in order to extend the life of the developing roller b, the surface of the developing roller b is hardly scraped by performing a plating process on the surface of the developing roller b. However, the life of the developing roller b is not sufficient if the surface of the developing roller b is simply plated.

  As another method for extending the life of the developing roller b, it has been proposed to form a concavo-convex pattern including regular grooves on the surface of the developing roller b (see, for example, Patent Document 2). As shown in FIG. 9B, the regular grooves c described in Patent Document 2 are inclined with respect to the axial direction (or circumferential direction) of the developing roller b and are formed with a predetermined width in the axial direction. ing. In that case, the regular grooves c are provided as a predetermined number of inclined grooves d and e in two types of inclination directions that are inclined in different opposite directions. According to the developing roller b having a surface on which these regular inclined grooves d and e are formed, scraping due to an external additive such as silica is suppressed compared to the developing roller b having an irregular surface roughness due to blasting. As a result, it has been confirmed that the durability is excellent and the life of the developing roller b is effectively extended.

By the way, as described above, the toner T is supplied onto the developing roller b by the toner supply roller a. At this time, the toner T is rotated on the developing roller b rotating in the rotation direction α in the same rotational direction as the developing roller b. The toner is supplied while being rubbed by a toner supply roller a rotating to α. At this time, in the developing roller b having the regular groove c described in Patent Document 2, the toner particles T on the developing roller b are transferred to the toner supply roller when the developing roller b rotates as shown in FIG. 9C. The force F ₁ is applied in a direction orthogonal to the axial direction of the developing roller b by a and a force F ₂ is applied by the inclined grooves d and e. Therefore, since the resultant force F in the direction substantially along one of the inclined directions of the inclined grooves d and e is applied to the toner particle T, the toner particle T moves substantially along one of the inclined grooves d and e. It becomes like this. That is, the toner particles T move toward one of both ends of the developing roller b by this movement.

However, in the developing roller b in which only one inclined groove d or inclined groove e in the inclined direction is formed, the toner particles T move along the inclined groove d (e) and only on one axial side of the developing roller b. There is a risk that toner will collect and toner will leak out from the end of the developing roller b.
However, in the case where two inclined grooves d and e having different inclination directions are provided, the toner that has moved along one of the inclined grooves d when it comes to the next intersection of the two inclined grooves d and e. The particles T collide with the toner particles T that have moved along the other inclined groove e. Then, the toner particles T that have moved along the one inclined groove d tend to move along the other inclined groove e, and the toner particles T that have moved along the other inclined groove e become one inclined groove e. The toner particles T that have moved along the grooves c and d tend to move in opposite directions. Thus, the toner particles T are prevented from collecting only on one side in the axial direction of the developing roller b, and the toner is prevented from leaking outside from the end of the developing roller b.
JP 2001-66876 A. JP 2000-56558 A.

  Incidentally, since the developing roller b described in Patent Document 1 has an irregular surface roughness due to blasting, the toner T supplied by the toner supply roller a is in contrast to the developing roller b. It moves in a direction substantially orthogonal to the axial direction of Therefore, in the developing roller b having an irregular surface roughness, the toner T supplied by the toner supply roller a is further moved from the both axial ends of the irregular surface roughness to the both ends of the developing roller b. There is little to move to.

  Further, since the developing roller b described in Patent Document 2 has a surface on which regular inclined grooves d and e are formed, as described above, the toner particles T are in contact with the inclined grooves d and e, and The toner supply roller a moves in the axial direction of the developing roller b. At this time, in the central region of the surface where the regular inclined grooves d and e having two different inclination directions are formed, the toner particles T are developed by the inclined grooves d and e while their axial movements are offset. It moves within a predetermined range in the axial direction of the roller b.

  However, when the regular inclined grooves d and e are provided in the developing roller b as described above, the toner particles T that have entered the inclined grooves d and e may not be reset. That is, the toner particles T on the developing roller b are not developed on the image carrier j, and the undeveloped toner particles T remain on the developing roller b. When the undeveloped toner particles T return to the toner supply roller along with the rotation of the developing roller b, they are scraped off from the developing roller b, and new toner is supplied to the developing roller b. The roller b is reset. However, if the developing roller b is not reset satisfactorily, the same toner always remains on the developing roller b, resulting in toner overcharging, toner deterioration, and developing roller filming.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide an inclined groove after development even when toner is supplied by a toner supply roller onto a developing roller having a regular inclined groove. It is an object of the present invention to provide a developing device that can effectively remove residual toner that has entered, and an image forming apparatus using the developing device.

  In order to solve the above-mentioned problem, a developing device according to the invention of claim 1 includes a developing roller that transports toner and a toner supply member that abuts against the developing roller and supplies toner to the developing roller. At least a roller, and at a predetermined position in the axial center of the outer peripheral surface of the developing roller is inclined with respect to the axial direction of the developing roller, and other from one end side of the developing roller with respect to the rotational direction of the developing roller A predetermined number of first inclined grooves proceeding to the end side and the other end of the developing roller inclined in the direction opposite to the first inclined groove with respect to the axial direction of the developing roller and the rotation direction of the developing roller In the developing device in which a groove overlapping portion made up of a predetermined number of second inclined grooves proceeding from the side to one end side is formed, the developing roller on the other end side of the developing roller with respect to the rotation direction of the developing roller A first inclined groove single forming portion is formed in which a predetermined number of third inclined grooves that advance from the axial center toward the other end of the developing roller are formed adjacent to the other end of the groove overlapping portion. In addition, a predetermined number of fourth inclined grooves proceeding from one axial center side of the developing roller toward one end side of the developing roller with respect to the rotation direction of the developing roller are provided on one end side of the developing roller. A second inclined groove single forming portion formed adjacent to the other end of the overlapping portion is formed, and the toner supply member of the toner supply roller is composed of a plurality of elastically bent hairs, and the toner The width of the supply member in the axial direction is set to be shorter than the width of the groove overlapping portion in the axial direction, and when the toner supply member is brought into contact with the image carrier, predetermined widths at both ends of the toner supply member are set. A number of hairs are said first and It is characterized in that it is in an elastically deflectable so than second inclined grooves alone forming section reaches the groove-free portion near both ends of the developing roller.

  In the developing device according to the second aspect of the present invention, the first inclined groove in the groove overlapping portion and the third inclined groove in the first inclined groove independent forming portion are formed as a continuous groove. In addition, the second inclined groove in the groove overlapping portion and the fourth inclined groove in the second inclined groove independent forming portion are formed as continuous grooves.

Further, the developing device according to the invention of claim 3 is characterized in that each of the first to fourth inclined grooves is formed of a spiral groove.
Furthermore, the developing device according to a fourth aspect of the invention is characterized in that the first and second inclined grooves are both formed continuously or intermittently.

  Further, in the developing device according to the fifth aspect of the present invention, the predetermined number of third inclined grooves and fourth inclined grooves respectively formed in the first and second inclined groove independent forming portions respectively have predetermined pitch intervals. The axial widths of the first and second inclined groove single forming portions are set larger than the pitch intervals of the third inclined groove and the fourth inclined groove, respectively. Yes.

  Furthermore, an image forming apparatus according to a sixth aspect of the invention includes an image carrier on which at least an electrostatic latent image is formed, a developing roller that supplies toner for developing the electrostatic latent image to the image carrier, and the development A developing device including at least a toner supply roller that supplies toner to the roller and a regulating blade that contacts the developing roller and regulates the amount of toner on the developing roller; and the electrostatic latent image on the image carrier is developed. An image forming apparatus comprising at least a transfer device that transfers the toner image to a transfer medium, wherein the developing device is the developing device according to any one of claims 1 to 5.

  According to the developing device according to the first to fifth aspects of the present invention, the other end of the developing roller from the one end side with respect to the rotation direction of the developing roller is placed at a predetermined position in the axial center of the outer peripheral surface of the developing roller. A groove overlapping portion composed of a predetermined number of first inclined grooves extending toward the end side and a predetermined number of second inclined grooves extending from the other end side of the developing roller to the one end side, and adjacent to the other end of the groove overlapping portion. A first inclined groove single forming portion formed with a third inclined groove that advances from the axial center side of the developing roller toward the other end side of the developing roller with respect to the rotation direction of the developing roller, and a groove overlapping portion Adjacent to the other end is a second inclined groove single forming portion formed with a fourth inclined groove that advances from the axial center of the developing roller toward the one end side of the developing roller with respect to the rotation direction of the developing roller. Many formed and elastically bent the toner supply member of the toner supply roller When the toner supply member is set to be shorter than the axial width of the groove overlapping portion and the toner supply member comes into contact with the image carrier, the toner supply Since a predetermined number of bristles at both end portions of the member can be elastically bent so as to reach the groove non-forming portion near both ends of the developing roller from the first and second inclined groove single forming portions, development is performed after development. When the residual toner remaining on the roller is returned to the toner supply roller, the toner can be reliably scraped off from the developing roller with a predetermined number of bristles of the brush.

  In addition, the toner in the first and second inclined grooves alone is positively applied to the toner in the first and second inclined grooves by the cooperative action of the first and second inclined grooves and the brush bristles. It can be swept out to both ends of the developing roller. In this case, the residual toner particles that have entered the first and second inclined grooves of the first and second inclined groove forming portions of the developing roller are also positively and actively removed from the first and second inclined grooves by the bristles of the brush. Can be dug and swept out effectively. Thus, the developing roller can be reliably reset by supplying new toner to the developing roller. Therefore, it is possible to obtain a favorable resetting property of the developing roller, and it is possible to suppress the occurrence of excessive charging of the toner, toner deterioration, filming of the developing roller, and the like.

  Further, since the width of the toner supply member of the toner supply roller is made shorter than the width of the groove overlapping portion, the amount of brush bristles contacting the first and second inclined groove independent forming portions should be set to an appropriate value. Can do. As a result, the bristles of the brush that are in contact with the first and second inclined groove single forming portions can be sufficiently elastically bent, so that the toner particles that have entered the first and second inclined grooves can be removed. It can be effectively scraped off and removed by the elasticity of.

  In particular, according to the developing device of the second aspect of the present invention, the first inclined groove in the groove overlapping portion and the third inclined groove in the first inclined groove independent forming portion are continuously formed as one common inclined groove. Since the second inclined groove in the groove overlapping portion and the fourth inclined groove in the second inclined groove single forming portion are formed as one continuous inclined groove, the first and second inclined grooves are formed. The toner particles that have moved to the single groove forming portion can be smoothly moved toward both ends of the developing roller.

In the developing device according to the third aspect of the present invention, since the first to fourth inclined grooves are all formed as spiral grooves, groove processing by the pressure roller is facilitated.
Further, according to the developing device of the fourth aspect of the present invention, the first and second inclined grooves are both formed continuously, so that the movement of the toner particles is further smoothed, and the developing roller by the toner particles is used. Therefore, the durability of the developing roller can be improved, and the life of the developing device can be extended accordingly. Further, by intermittently forming both the first and second inclined grooves, the toner can be favorably frictionally charged on the developing roller.

  Furthermore, according to the developing device of the invention of claim 5, the axial width of the first inclined groove single forming portion is set larger than the pitch interval of the third inclined grooves in the first inclined groove single forming portion, Further, since the axial width of the second inclined groove single forming portion is set larger than the pitch interval of the fourth inclined grooves in the second inclined groove single forming portion, the first and second inclined groove single forming portions are formed. The third and fourth inclined grooves can be arranged at any position in the circumferential direction over the entire circumference. Therefore, the above-mentioned cooperative action of the first and second inclined grooves and the bristles of the brush can be performed more effectively, and the toner in the first and second inclined grooves can be more reliably secured to both end sides of the developing roller. Can be swept out.

  Further, according to the image forming apparatus of the invention of the sixth aspect, the developing roller can be prevented from being scraped by the toner particles to which the external additive is added, and the developing roller can have excellent durability. Thus, the toner can be effectively frictionally charged on the developing roller over a long period of time, and toner leakage can be prevented. Therefore, good image formation can be performed for a long time, and contamination in the developing device due to toner leakage can be prevented for a long time.

The best mode for carrying out the present invention will be described below with reference to the drawings.
FIG. 1 is a cross-sectional view schematically showing an example of an embodiment of an image forming apparatus according to the present invention, and FIG. 2 schematically shows a developing device common to each developing device used in the image forming apparatus of this example. FIG.

  As shown in FIG. 1, the image forming apparatus 1 of this example is formed as a tandem type image forming apparatus and has a housing body 2. In the housing main body 2, an image forming unit 3, an intermediate transfer unit (hereinafter also referred to as a primary transfer unit) 4, a paper feed unit 5, a secondary transfer unit 6, a fixing unit 7, and a recording medium conveying unit 8 are respectively provided. It is arranged. Consumables in the image forming unit 3 and the paper feeding unit 5 are configured to be detachable from the housing main body 2, and these can be removed and repaired or exchanged including the primary transfer unit 4.

  The image forming unit 3 has a plurality of different colors (in this example, four colors, but for example, two or three of the four colors may be used; hereinafter, described as four colors), that is, yellow (Y) A yellow image forming station 9Y, a magenta image forming station 9M, a cyan image forming station 9C, and a black image forming station 9K that respectively form magenta (M), cyan (C), and black (K) images. I have. In this case, in this example, the arrangement order of the image forming stations 9Y, 9M, 9C, and 9K for the respective colors Y, M, C, and K is linearly arranged in this order in the diagonally lower right direction in FIG. . The arrangement order of the image forming stations 9Y, 9M, 9C, and 9K for each color is not limited to this, and can be arbitrarily set.

  These image forming stations 9Y, 9M, 9C, and 9K are respectively provided around the image carriers 10Y, 10M, 10C, and 10K including photosensitive drums, and the image carriers 10Y, 10M, 10C, and 10K. The charging devices 11Y, 11M, 11C, and 11K that charge the image carriers 10Y, 10M, 10C, and 10K, and the image writing device 12Y that writes a latent image on the image carriers 10Y, 10M, 10C, and 10K. , 12M, 12C, 12K, developing devices 13Y, 13M, 13C, 13K for developing the latent images on the image carriers 10Y, 10M, 10C, 10K, and static eliminating for the image carriers 10Y, 10M, 10C, 10K The devices 14Y, 14M, 14C, and 14K, and the cleaners 15Y, 15M, 15C, and 15K for cleaning the image carriers 10Y, 10M, 10C, and 10K are provided.

  Image carriers 10Y, 10M, 10C, and 10K for image forming stations 9Y, 9M, 9C, and 9K for each color, charging devices 11Y, 11M, 11C, and 11K, image writing devices 12Y, 12M, 12C, and 12K, and developing devices 13Y, The configurations of 13M, 13C, and 13K, the static eliminators 14Y, 14M, 14C, and 14K, and the cleaners 15Y, 15M, 15C, and 15K are all the same regardless of the colors Y, M, C, and K.

  Each charging device 11Y, 11M, 11C, 11K includes a charging roller composed of a conductive rubber roller connected to a high voltage generation source, and the surface of each image carrier 10Y, 10M, 10C, 10K corresponding to each charging roller. Is uniformly charged.

  Each of the image writing devices 12Y, 12M, 12C, and 12K uses an LED line head in which LED lamps are arranged in a line in the axial direction of the image carriers 10Y, 10M, 10C, and 10K. Since the LED line head has a shorter optical path length than the laser scanning optical system and is more compact, the LED line head can be disposed close to the image carriers 10Y, 10M, 10C, and 10K, and the apparatus main body can be downsized. Have.

  As shown in FIG. 2, the developing devices 13Y, 13M, 13C, and 13K are formed in the developing device housings 16Y, 16M, 16C, and 16K, and the developing device housings 16Y, 16M, 16C, and 16K, respectively. The toner storage units 17Y, 17M, 17C, and 17K that store the toners TY, TM, TC, and TK, and the toner storage units 17Y, 17M, 17C, and 17K, respectively, are provided with the toners TY, TM, TC, and TK. The toner agitating members 18Y, 18M, 18C, and 18K to be agitated and the developing device housings 16Y, 16M, 16C, and 16K are provided in the toner storage portions 17Y, 17M, 17C, and 17K, respectively. The toner supply rollers 19Y, 19M, 19C, and 19K supplied from 17K and the toner supply rollers provided in the developing device housings 16Y, 16M, 16C, and 16K, respectively. Developing rollers 20Y, 20M, 20C, and 20K that transport the toners TY, TM, TC, and TK supplied from 19Y, 19M, 19C, and 19K to the image carriers 10Y, 10M, 10C, and 10K, and the developing rollers 20Y, respectively. , 20M, 20C, and 20K are provided with regulating blades 21Y, 21M, 21C, and 21K that regulate the thicknesses of the toner layers of the toners TY, TM, TC, and TK, respectively.

  The developing rollers 20Y, 20M, 20C, and 20K and the toner supply rollers 19Y, 19M, 19C, and 19K have the same rotation direction, and are opposite to the rotation directions of the image carriers 10Y, 10M, 10C, and 10K. It is rotationally driven in the clockwise rotation direction α. The toners TY, TM, TC, and TK of the respective colors that are stirred by the toner stirring members 18Y, 18M, 18C, and 18K in the toner storage portions 17Y, 17M, 17C, and 17K are respectively supplied to the toner supply rollers 19Y, 19M, 19C, and 19K is supplied to the surface of each developing roller 20Y, 20M, 20C, 20K. The toners TY, TM, TC, and TK supplied to the developing rollers 20Y, 20M, 20C, and 20K are regulated to a predetermined thin thickness by the regulating blades 21Y, 21M, 21C, and 21K, respectively. The toners TY, TM, TC, TK thinned by the above are conveyed to the image carriers 10Y, 10M, 10C, 10K. Then, the electrostatic latent images of the respective colors of the image carriers 10Y, 10M, 10C, and 10K are developed by the toners TY, TM, TC, and TK conveyed by the developing rollers 20Y, 20M, 20C, and 20K, respectively. .

By the way, in each of the developing devices 13Y, 13M, 13C, and 13K of the image forming apparatus 1 of this example, the outer peripheral surface of each of the developing rollers 20Y, 20M, 20C, and 20K is the same as the developing roller described in Patent Document 2 described above. An uneven pattern is formed on the surface.
FIG. 3 is a diagram schematically showing the developing roller of this example together with the toner supply roller. In the following description with reference to FIGS. 3 to 8, since the colors Y, M, C, and K are common, the description will be made with the Y, M, C, and K codes deleted from the respective codes.

As shown in FIG. 3, in the developing roller 20 of the developing device 13 of this example, a spiral groove 22 is formed at a predetermined position on the outer peripheral surface as the uneven pattern. In that case, the spiral groove 22 is formed with a predetermined pitch interval p in the axial direction and a predetermined width W ₁ in the axial direction, and when the developing roller 20 rotates in the rotational direction α, that is, the rotational direction of the developing roller 20. 3, a predetermined predetermined number of first inclinations formed of spiral grooves formed continuously from the right end side (one end side) of the developing roller 20 in FIG. 3 toward the left end side (the other end side). Grooves 22a are formed in the axial direction with the same pitch interval p as the first inclined grooves 22a and in the axial direction with the same width W ₂ (W ₂ = W ₁ ) as the first inclined grooves 22a. When rotating to α, that is, with respect to the rotation direction α of the developing roller 20, in FIG. 3, the spiral shape formed continuously from the left end side (the other end side) of the developing roller 20 toward the right end side (one end side). The same number of regular second inclinations as the first inclined grooves 22a made of grooves. It consists of a slanting groove 22b. In other words, the regular spiral groove 22 in this example has first and second inclined grooves 22a in two kinds of inclination directions inclined in opposite directions different from each other with respect to the axial direction (or circumferential direction) of the developing roller 20. , 22b.

  Note that the pitch interval p and the number of the second inclined grooves 22b are not necessarily the same as those of the first inclined grooves 22a and may be different. Further, the number of the first and second inclined grooves 22a and 22b can be one or more and an arbitrary number.

The first inclined groove 22a is formed from the left end position 22a ₁ from the left end 20a by a predetermined distance in the axial center of the developing roller 20 to the right end position 22a ₂ having a predetermined width W ₁ to the right, and the second The inclined groove 22b is formed from the right end 20b of the developing roller 20 to the left end position 22b _{2 having} a predetermined width W ₁ from the right end position 22b ₁ on the axial center side by a predetermined distance. Thereby, the formation region of the first inclined groove 22a is slightly leftward in the axial direction from the axial center position of the developing roller 20, and the formation region of the second inclined groove 22b is slightly slightly axially from the axial center position of the developing roller 20. It is on the right side. The left end position 22a ₁ of the first inclined groove 22a and the right end position 22b ₁ of the second inclined groove 22b, and the right end position 22a ₂ of the first inclined groove 22a and the left end position 22b ₂ of the second inclined groove 22b are respectively the developing roller 20. It is set symmetrically with respect to the axial center.

Thus, the first and second inclined grooves 22a, 22b has a width W of the axial region from the left end position 22b ₂ to the right edge position 22a ₂ of the first inclined groove 22a of the second inclined groove 22b overlap intersect one another ₃ groove overlapping portions 20c. The groove overlapping portion 20c is adapted to face the image forming area of the image carrier. Further, adjacent to the left end of the groove overlap portion 20c of the developing roller 20, the axial direction of the region from the left end position 22a ₁ to the left end position 22b ₂ of the second inclined groove 22b of the first inclined groove 22a is, the grooves overlap portion 20c there is a first inclined groove alone forming portion 20d of the axial width W ₄ of the first inclined groove 22a continuously in the left end is formed. Furthermore, adjacent to the right end of the groove overlap portion 20c of the developing roller 20, the axial direction of the region from the right end position 22a ₂ to the right end position 22b ₁ of the second inclined groove 22b of the first inclined groove 22a is, the grooves overlap portion 20c there is a second inclined groove alone forming portion 20e of the axial width W ₅ of the second inclined groove 22b in succession to the right end is formed. In that case, the widths W ₄ and W ₅ of the first and second inclined groove single forming portions 22d and 20e are both set to be larger than the pitch interval p between the corresponding first and second inclined grooves 22a and 22b. .

Furthermore, with the outer peripheral surface of the developing roller 20 between the left end position 22a ₁ of the left end 20a and the first inclined groove 22a is a left side of the groove-free portion 20f of the developing roller 20, and the right end 20b of the developing roller 20 first The outer peripheral surface of the developing roller 20 between the right end position 22b ₁ of the two inclined grooves 22b is the right groove non-forming portion 20g. Therefore, the total groove forming portion of the first inclined groove 22a in the axial direction of the region width W ₆ of the left end position 22a developing roller 20 from ₁ to the right end position 22b ₁ of the second inclined groove 22b (20c, 20d, 20e) and It has become.

  In the developing device 13 of this example, of the first inclined grooves 22a, the first inclined groove 22a formed in the groove overlapping portion 20c constitutes the first inclined groove of the present invention, and the second inclined groove. 22b, the second inclined groove 22b formed in the groove overlapping portion 20c constitutes the second inclined groove of the present invention, and further, in the first inclined groove 22a, formed in the first inclined groove independent forming portion 20d. The first inclined groove 22a formed constitutes the third inclined groove of the present invention, and the second inclined groove 22b formed in the second inclined groove independent forming portion 20e of the second inclined groove 22b is the present invention. This constitutes a fourth inclined groove. Therefore, the first inclined groove and the third inclined groove in the present invention are constituted by one continuous first inclined groove 22a, and the second inclined groove and the fourth inclined groove in the present invention are continuous. It is constituted by one common second inclined groove 22b. In FIG. Reference numerals 20 h and 20 i are rotation axes of the developing roller 20.

Next, the groove processing method of the developing roller 20 in this example will be described.
As the groove processing method of the developing roller 20 in this example, for example, a conventionally known groove processing method including the groove processing method described in Patent Document 2 can be adopted. 4A to 4C are diagrams for simply explaining an example of a groove processing method of the developing roller 20.

  In the groove processing method of the developing roller 20 in this example, as shown in FIG. 4A, first, the processing step of the first inclined groove 22a is performed. That is, in this processing step, the base 20 'of the developing roller 20 is set at a predetermined position of a pair of holding rollers 23 (only one is shown in FIG. 4A). Examples of the material of the base 20 'include metal materials such as aluminum and iron described in Patent Document 2, non-metal materials such as various resins such as ABS and PPF, and ceramics, and are conventionally used for developing rollers. Material can be used.

Next, the base body 20 ′ is rotated in a rotation direction β opposite to the rotation direction α when the developing roller 20 is used, and a predetermined number of first and second uneven patterns for forming a predetermined number of first inclined grooves 22 a are formed. The pressure roller 24 having one spiral protrusion 24a is abutted and pressed against the rotating base 20 'while being rotated in a rotation direction γ opposite to the rotation direction β. The width (axial length) of the first spiral ridge 24a is while being set equal to the width W ₁ of the first inclined groove 22a, the left end position 24a ₁ of the first spiral ridge 24a is first inclined It is set to be the left end position 22a ₁ ′ of the base body 20 ′ corresponding to the left end position 22a ₁ of the groove 22a. As a result, a predetermined number of first inclined grooves 22a ′ on the substrate are formed in the substrate 20 ′. When the processing of the first inclined groove 22a ′ on the base to the base 20 ′ is completed, the pressure roller 24 is removed from the processing machine.

Next, as shown in FIG. 4 (b), the base 20 'in which the first inclined groove 22a' on the base is formed in this way is left axially from the position when the first inclined groove 22a 'on the base is formed. Are set at predetermined positions of the pair of holding rollers 23 shifted by a predetermined amount. The amount of deviation of the base body 20 ′ on the left side in the axial direction is set to an amount equal to the width W ₄ of the first inclined groove single forming portion of the developing roller 20. In the same manner as described above, the base body 20 ′ is rotated in the rotational direction β, and a pressurization provided with a predetermined number of second spiral protrusions 25 a that are concave and convex patterns for forming the predetermined number of second inclined grooves 22 b. While the roller 25 is rotated in a rotational direction γ opposite to the rotational direction β, the roller 25 is brought into contact with and pressed against the rotating base body 20 ′. The width (axial length) of the second spiral ridge 25a is while being set equal to the width W ₂ of the second inclined groove 22b, the left end position 25a ₁ of the second spiral ridge 25a and the second inclined It is set to be the left end position 22b ₂ ′ of the base body 20 ′ corresponding to the left end position 22b ₂ of the groove 22b. As a result, a predetermined number of second inclined grooves 22b ′ on the base body are formed in the base body 20 ′.

  Thus, on the outer peripheral surface of the base body 20 ′, the first on-base base first spiral forming portion 20a ′ on the left end side and the second on-base base single spiral forming portion 20b ′ are formed between them. Then, a base-side groove overlapping portion 20c ′ is formed in which the base-side first inclined groove 22a ′ and the base-side second inclined groove 22b ′ intersect and partially overlap each other.

  Finally, by performing predetermined electrodeposition coating on the outer peripheral surface of the base body 20 'as in the prior art, as shown in FIG. 4 (c), the first spiral single forming portion 20d on the left end side and the right end side Development roller 20 in which a second spiral independent forming portion 20e and a groove overlapping portion 20c formed between them and the first inclined groove 22a and the second inclined groove 22b intersect and partially overlap each other are formed. Is completed.

  The groove processing method of the developing roller 20 is not limited to using two types of pressure rollers as in the above-described example, but a predetermined number of first and first rollers as shown in FIG. The first and second inclined grooves 22a and 22b can be simultaneously processed by one pressure roller 26 provided with the second spiral protrusions 24a and 25a. In this case, it is not necessary to move the base body 20 'in the axial direction.

As shown in FIG. 3, the toner supply roller 19 is formed by fixing a toner supply member 19b to the outer peripheral surface of a cored bar 19a. The toner supply roller 19 is formed as a brush roller, and the toner supply member 19b is composed of a brush having a large number of soft and elastically deformable hairs 19b ₁ implanted in the cored bar 19a. The axial width (flocking width) W _{7 of the} toner supply member 19 b is set to be shorter than the width W ₃ of the groove overlapping portion 20 c of the developing roller 20. For the bristles 19b ₁ , for example, a soft and elastically deformable resin material such as nylon is used.

The toner supply roller 19 is disposed such that its axial center coincides with or substantially coincides with the axial center of the developing roller 20. In addition, by the toner supplying member 19b may be pressed against the developing roller 20, as bristles 19b ₁ to be pressed against the developing roller 20 at its both end portions are elastically flexural deformation toward the direction of both ends of the developing roller 20 It has become. In that case, the tip portions of the predetermined number of bristles 19b _{1 which} are elastically bent and deformed are set so as to reach the region of the groove non-forming portions 20f, 20g beyond the first and second inclined groove independent forming portions 20d, 20e. Has been. Therefore, the width W ₈ maximum deflection brush total groove forming portions (20c, 20d, 20e) is set larger than the width W ₆ of. Thus, a toner supplying member 19b is at the time of contact with the developing roller 20, the hair 19b ₁ groove overlap portion 20c of the brush, the first and second inclined grooves alone forming portion 20d, 20e, and the groove non-formed part 20f, 20 g It comes to contact a part of.

  In the developing device 13 of this example configured as described above, both the toner supply roller 19 and the developing roller 20 rotate in the rotation direction α during the developing operation, and the toner is transferred from the toner supply roller 19 to the developing roller 20 as in the conventional case. And the toner layer thickness on the developing roller 20 is regulated by the regulating blades (regulating blades 21Y, 21M, 21C, and 21K shown in FIG. 2) and the image carrier (shown in FIG. 2). Image carrier 10Y, 10M, 10C, 10K). At this time, the toner particles T on the groove overlapping portion 20c of the developing roller 20 are transferred to the first and second inclined grooves 22a and 22b of the developing roller 20 and the regulating blade 21 in the same manner as in the conventional example described above. It flows while being guided along the inclined grooves 22a and 22b.

Then, in the groove overlap portion 20c, in the vicinity of the left end position 22b ₂ of the second inclined groove 22b, the first inclined groove alone toner particles from the grooves overlap portion 20c to flow is guided along the second inclined groove 22b It penetrates into the region of the forming part 20d. However, as shown in FIG. 5, the toner particles T that have entered the region of the first inclined groove single forming portion 20d have the same force F ₁ in the direction perpendicular to the axial direction of the developing roller 20 by the first inclined groove 22a. It will receive the resultant force F and the force F ₂ directed in the axial direction a and the axial center of the developing roller 20 according to the first inclined groove 22a. Then, the toner particles T on the first inclined groove forming part 20d are substantially along the first inclined groove 22a by the rotation of the developing roller 20 in the rotation direction α while receiving the resultant force F, and the axial direction of the developing roller 20 It starts to flow toward the center. Therefore, the toner particles T that have entered the region of the first inclined groove single forming portion 20d are prevented from entering the groove non-forming portion 20f that is continuous to the left side of the first inclined groove single forming portion 20d, and further the developing roller. Leakage from the left end of 20 is effectively prevented.

  Although not shown in the drawing, the toner particles T that have entered the region of the second inclined groove single forming portion 20e are also reversed in the left-right direction from the toner particles T that have entered the region of the first inclined groove single forming portion 20d. Under the same resultant force, it flows toward the axial center of the developing roller 20 substantially along the second inclined groove 22b. Therefore, the toner particles T that have entered the region of the second inclined groove single forming portion 20e are also prevented from entering the groove non-forming portion 20g that is continuous to the right side of the second inclined groove single forming portion 20e, and further the developing roller. Leakage from the right end of 20 is effectively prevented.

Further, after the toner on the developing roller 20 is developed on the image carrier 10, the undeveloped toner remaining on the developing roller 20 is moved again toward the toner supply member 19 b by the rotation of the developing roller 20. Developing the remaining toner on the developing roller 20 has reached the toner supply member 19b is scraped off from the developing roller 20 by the elastic force of the hair 19b ₁ of the brush, the toner storing portion of the developing device 13 (toner storage shown in FIG. 2 Part 17Y, 17M, 17C, 17K) again. In that case, the first and second inclined groove 22a of the developing roller 20, the toner particles falls within 22b, the first and second inclined groove 22a by hair 19b ₁ of the brush, 22b effectively dug and removed from the Is done.

  As shown in FIG. 1, the static eliminators 14Y, 14M, 14C, and 14K are disposed between the primary transfer portions 4Y, 4M, 4C, and 4K and the cleaners 15Y, 15M, 15C, and 15K in the image forming unit 3, respectively. ing. These neutralization devices 14Y, 14M, 14C, and 14K are configured to neutralize the image carriers 10Y, 10M, 10C, and 10K after the primary transfer is completed.

  The primary transfer unit 4 includes a driving roller 29 that is rotationally driven by a driving source (not shown) that is rotatably supported below the housing body 2, and a driven roller 30 that is rotatably supported above the housing body 2. The intermediate transfer belt 31 is provided between the drive roller 29 and the driven roller 30 and is driven to rotate counterclockwise as indicated by an arrow in FIG.

The intermediate transfer belt 31 is in contact with the image carriers 10Y, 10M, 10C, and 10K at the primary transfer portions 4Y, 4M, 4C, and 4K, and each color is transferred from the image carriers 10Y, 10M, 10C, and 10K. The toner image is primarily transferred (intermediate transfer). The intermediate transfer belt 31 is provided with, for example, a cleaning device 32 in the vicinity of the driven roller 30, and the cleaning device 32 collects transfer residual toner for secondary transfer.

  Each of the cleaners 15Y, 15M, 15C, and 15K is conventionally known, and cleans the transfer residual toner remaining on the image carriers 10Y, 10M, 10C, and 10K after the primary transfer.

  As shown in FIG. 1, the paper feeding unit 5 includes a paper feeding cassette 35 in which recording media R such as paper are stacked and held, and a pickup roller 36 that feeds the recording media R from the paper feeding cassette 35 one by one. And a paper feed unit. Further, the housing body 2 is provided with a registration roller pair 37 that defines the timing of feeding the recording medium R to the secondary transfer portion.

  The secondary transfer unit 6 includes a secondary transfer roller 38 that presses the intermediate transfer belt 31 against the driving roller 29 in the secondary transfer portion. At this time, the drive roller 29 of the primary transfer unit 4 also serves as a backup roller for the secondary transfer roller 38.

Further, the fixing unit 7 includes a rotatable heating roller 39 incorporating a heating element such as a halogen heater, and a pressure roller 40 that presses and biases the heating roller 39. The color image secondarily transferred to the recording medium R in the secondary transfer portion is fixed to the recording medium R at a predetermined temperature in the nip portion formed by the heating roller 39 and the pressure roller 40 of the fixing unit 7. The
Further, there are a pair of discharge rollers 42 for discharging the recording medium R after fixing to the discharge tray 41, and a double-sided printing conveyance path 43 for conveying the recording medium R to form images on both sides of the recording medium R. It is arranged.

  The entire image forming operation in the image forming apparatus 1 of this example is such that the image forming stations 9Y, 9M, 9C, and 9K for each color are arranged in tandem, and the primary transfer unit 4, the paper feeding unit 5, and the secondary transfer unit. 6 is the same as the image forming operation in a conventionally known tandem type image forming apparatus provided with the fixing unit 7 and the recording medium conveying means 8 and is not directly related to the operation of the characteristic part of the present invention. Omitted.

According to the developing device 13 used in the image forming apparatus 1 of this example, the central region in the axial direction of all the groove forming portions is the groove overlapping portion 20c formed by two different types of grooves 22a and 22b in the inclined direction. Both end regions of all the groove forming portions are continuous with the groove overlapping portion 20c and proceed toward both ends of the developing roller 20 with respect to the rotation direction α of the developing roller 20 (on the opposite side to the groove overlapping portion 20c side). The first and second inclined groove independent forming portions 20d and 20e including the first and second inclined grooves 22a and 22b are formed, and the tip portions of the predetermined number of bristles 19b ₁ of the brush are not grooved at the left and right end portions of the developing roller 20. Since the toner reaches the forming portions 20f and 20g, when the toner remaining on the developing roller 20 is returned to the toner supply roller 19 after development, the toner is displayed on the predetermined number of bristles 19b ₁ of the brush. It can be reliably scraped off from the image roller 20.

Moreover, the first and second inclined grooves alone forming portion 20d, the toner present in 20e, the first and second inclined grooves 22a, by for 22b and brush bristles 19b ₁ cooperation of the first and second inclined The toner T in the grooves 22a and 22b can be positively swept out to both ends of the developing roller 20. In this case, developing the first and second inclined grooves alone forming portion 22d of the roller 20, first and second inclined groove 22a of 22e, the toner particles falls within 22b also, the first and second by bristle 19b ₁ of the brush It is possible to positively and effectively excavate from the inclined grooves 22a and 22b and to sweep out to both ends of the developing roller 20. Thus, by supplying new toner to the developing roller 20, the developing roller 20 can be reliably reset. Therefore, it is possible to obtain a favorable resetting property of the developing roller 20, and to suppress the occurrence of excessive toner charging, toner deterioration, filming of the developing roller, and the like.

  Further, since both the first and second inclined grooves 22a and 22b are continuously formed, the movement of the toner particles T can be made smoother and the wear of the developing roller 20 due to the toner particles T can be suppressed. As a result, the life of the developing device can be extended accordingly.

Furthermore, since the width W ₇ of the toner supply member 19b of the toner supply roller 19 is made shorter than the width W ₃ of the groove overlap portion 20c, the first and second inclined grooves alone forming unit 22 d, the 22e abutting bristles The amount of 19b ₁ can be set to an appropriate value. As a result, the brush bristles 19b ₁ contacting the first and second inclined groove single forming portions 22d and 22e can be elastically sufficiently bent, so that they enter the first and second inclined grooves 22a and 22b. I toner - particle can sweep dropped effectively off by the elasticity of hair 19b ₁ of the brush.

Furthermore, the axial width W ₄ of the first inclined groove single forming portion 20d is set to be larger than the pitch interval p of the first inclined grooves 22a in the first inclined groove single forming portion 20d, and the second inclined groove single forming is also performed. Since the axial width W ₅ of the portion 20e is set to be larger than the pitch interval p of the second inclined grooves 22b in the second inclined groove forming portion 20e, the first and second inclined groove forming portions 20d, 20e. The first and second inclined grooves 22a and 22b can be disposed at any position in the circumferential direction over the entire circumference. Thus, the first and second inclined grooves 22a, by a previously described in cooperation with the hair 19b ₁ and 22b and the brush, the first and second inclined grooves 22a, the toner in the 22b more reliably developing roller 20 Can sweep to both ends.

  Furthermore, according to the image forming apparatus 1 using the developing device 13 of this example, the developing roller 20 is prevented from being scraped by the toner particles T to which the external additive is added, and the developing roller 20 has excellent durability. In addition, the life of the developing roller 20 can be extended more effectively. Therefore, according to the image forming apparatus of this example, it is possible to satisfactorily charge the toner on the developing roller over a long period of time, and to prevent leakage of the toner, so that it is possible to form a good image for a long period of time. At the same time, it is possible to prevent the developing device from being soiled for a long time due to toner leakage.

  In the above-described example, the two first and second inclined grooves 22a and 22b are formed in a continuous spiral groove, but the present invention is not limited to this, as shown in FIG. In addition, the two grooves 22a and 22b can be formed in an intermittent spiral regular groove without being continuous. In this case, the toner particles T can be satisfactorily charged on the developing roller 20 by intermittently forming the first and second inclined grooves 22a and 22b.

  In the above-described example, the first and second inclined grooves 22a and 22b are formed continuously from the first and second inclined groove forming portions 22d and 22e to the groove overlapping portion 20c. The first and second inclined grooves 22a and 22b formed in the second inclined groove forming portions 22d and 22e and the first and second inclined grooves 22a and 22b formed in the groove overlapping portion 20c are not necessarily continuous. Alternatively, they may be formed separately. Further, the first and second inclined groove single forming portions 22d and 22e and the groove overlapping portion 20c are formed continuously with each other, but the first and second inclined groove single forming portions 22d and 22e are overlapped with each other. The portion 20c is not necessarily provided continuously, and a narrow groove non-forming portion can be provided in the axial direction between the first and second inclined groove forming portions 22d and 22e and the groove overlapping portion 20c.

  Further, the groove 22 on the developing roller 20 is not limited to a spiral groove, and may be formed in a meandering groove extending in the axial direction or the circumferential direction of the developing roller 20. Also in this case, the first and second inclined groove single forming portions 22d and 22e are developed with respect to the rotation direction α of the developing roller 20, similar to the first and second inclined grooves 22a and 22b in the above example. Inclined grooves are formed that run from the axially central side of the roller 20 toward both end sides of the developing roller 20.

A specific example of the developing device 13 of this example will be described. The developing device 13 of the present invention is not limited to this. In the following description, the reference numerals with “′” correspond to FIGS. 4 (a) and 4 (b).
As shown in FIGS. 7A and 8, the base 20 ′ of the developing roller 20 is made of iron, the diameter φ is 18 mm, and the grooves of the first and second spiral grooves 22 a ′ and 22 b ′ forming the groove 22. The depth p is 0.1 mm and the width W ₃ of the groove overlapping portion 20c 'is 300 mm, the first and second inclined groove independent forming portions 20d. The width of ', 20e' (the amount of axial displacement of the first and second inclined grooves) W ₄ , W ₅ is 1 mm, and the width of all groove forming portions is 302 mm. Then, the developing roller 20 is completed by appropriately performing predetermined electrodeposition coating on the outer peripheral surface of the base body 20 'in the same manner as in the prior art. In the developing roller 20 of this specific example, first and second inclined groove single forming portions 20d and 20e having the same sizes as the first and second inclined groove single forming portions 20d ′ and 20e ′ are formed. Further, the rotating shafts 20h and 20i of the developing roller 20 are coaxially projected from both left and right ends of the developing roller 20 in the axial direction.

Further, as shown in FIGS. 7B and 8, the toner supply roller 19 has a large number of soft and elastically deformable nylon bristles 19b ₁ implanted on the outer peripheral surface of an iron core bar 19a having a diameter of 8 mm. It is formed as a brush roller. Width clogging flocking width W ₇ of the toner supply member 19b is 298 mm. The length of the brush bristles 19b _{1 in} the free state (plant height) is 6 mm. Therefore, the outer diameter of the toner supply member 19b is φ20 mm. The thickness of the brush bristles 19b ₁ is 330 tex. The distance between the axes of the toner supply roller 19 and the developing roller 20 is 17.5 mm, and therefore the amount of biting of the bristles 19b ₁ with respect to the developing roller 20 is 1.5 mm. Further, the axial distance deformation amount in the axial direction of hair 19b ₁ of the brush at the ends of the toner supply member 19b (the planted position of hair 19b ₁ to the tip in contact with the developing roller 20 of the bristle 19b ₁ at this time ) Is a maximum of 3.97 mm.

As shown in FIG. 8, the toner supply roller 19 and the developing roller 20 have their axial centers coincide with each other and the toner supply roller 19 is brought into contact with the developing roller 20 with the above-described biting amount. Arranged in this way. The tips of the brush bristles 19b ₁ at both ends of the toner supply member 19b reach the areas of the non-grooved portions 20f and 20g of the developing roller 20.

Therefore, the toner supply member 19b of the brush overlap groove over the axial entire width of the bristle 19b ₁ part 20c, the first and second inclined grooves alone forming section 20d, in contact with the 20e. In that case, the first and second inclined groove single forming portions 20d and 20e are respectively provided with the first and second developing rollers 20 with respect to the rotation direction α of the developing roller 20, respectively, from the central side in the axial direction toward both ends. Second inclined grooves 22a and 22b are formed. Then, the tip of the brush bristles 19b ₁ can reach all of the first and second inclined grooves 22a and 22b in the first and second inclined groove independent forming portions 20d and 20e.

  The developing device of the present invention is preferably used for a developing device including at least a developing roller having a regular inclined groove formed on the outer peripheral surface and a toner supply roller including a brush roller for supplying toner to the developing roller. In addition, the image forming apparatus of the present invention can be suitably used for an image forming apparatus that forms an image by developing an electrostatic latent image on an image carrier using such a developing device.

1 is a cross-sectional view schematically showing an example of an embodiment of an image forming apparatus according to the present invention. FIG. 2 is a cross-sectional view schematically showing a developing device common to the developing devices used in the image forming apparatus of the example shown in FIG. 1. FIG. 2 is a diagram schematically illustrating a developing roller used in the developing device of the example illustrated in FIG. 1 together with a toner supply roller. (A) And (b) is a figure explaining an example of the groove processing method of the developing roller of the example shown in FIG. 3, (c) is a figure which shows the developing roller processed by this groove processing method, (d) is development It is a figure which shows the other example of the groove processing method of a roller. FIG. 4 is a partially enlarged view for explaining the behavior of toner particles on the developing roller in the example shown in FIG. 3. It is a figure which shows the other example of the developing roller used for the image development apparatus of this invention. (A) is a figure which shows the specific example of the developing roller used for the image development apparatus of this invention, (b) is a figure which shows the specific example of the toner supply roller. It is a figure explaining arrangement | positioning of the developing roller shown in FIG. 7, a toner supply roller, and a control blade. (A) is a side view schematically showing a conventional developing roller and toner supply roller having regular grooves, and (b) is a perspective view schematically showing a conventional developing roller and toner supply roller having regular grooves. FIG. 4C is a diagram for explaining the behavior of the toner particles on the developing roller shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus, 2 ... Housing main body, 3 ... Image forming unit, 4 ... Intermediate transfer unit (primary transfer unit), 4Y, 4M, 4C, 4K ... Primary transfer part of each color, 6 ... Secondary transfer unit, 7 ... fixing unit, 8 ... recording medium conveying means, 9Y, 9M, 9C, 9K ... image forming station, 10Y, 10M, 10C, 10K ... image carrier, 11Y, 11M, 11C, 11K ... charging device, 12Y, 12M, 12C, 12K ... Image writing device, 13, 13Y, 13M, 13C, 13K ... Developing device, 14Y, 14M, 14C, 14K ... Static eliminating device, 19 ... Toner supply roller, 19a ... Core metal, 19b ... Toner supply member, 19b ₁ ... brush hair, 20 ... developing roller, 20c ... groove overlapping part, 20d ... first inclined groove single forming part, 20e ... second inclined groove single forming part, 20f, 20g ... groove non-forming part, 21 ... regulation Bray , 22 ... oblique grooves, 22a ... left end of the first inclined groove, 22a ₁ ... first inclined groove 22a, 22a ₂ ... right end position of the first inclined groove 22a, 22b ... second inclined groove, 22b ₁ ... second inclined Right end position of the groove 22b, 22b ₂ ... Left end position of the second inclined groove 22b, 31 ... Intermediate transfer belt

Claims (6)

A developing roller that conveys the toner; and a toner supply roller that has a toner supply member that contacts the developing roller and supplies the toner to the developing roller; and at a predetermined position in the axial center of the outer peripheral surface of the developing roller A predetermined number of first inclined grooves which are inclined with respect to the axial direction of the developing roller and proceed from one end side to the other end side of the developing roller with respect to the rotational direction of the developing roller, and in the axial direction of the developing roller On the other hand, a groove overlapping portion formed of a predetermined number of second inclined grooves which are inclined in the opposite direction to the first inclined grooves and proceed from the other end side to the one end side of the developing roller with respect to the rotation direction of the developing roller. In the developing device in which is formed,
On the other end side of the developing roller, a predetermined number of third inclined grooves proceeding from the axial center side of the developing roller toward the other end side of the developing roller with respect to the rotation direction of the developing roller overlap the groove. A first inclined groove forming portion formed adjacent to the other end of the developing portion is formed, and at the one end side of the developing roller, the axially central side of the developing roller with respect to the rotation direction of the developing roller A second inclined groove independent forming portion is formed in which a predetermined number of fourth inclined grooves proceeding from the developing roller toward one end side of the developing roller are formed adjacent to the other end of the groove overlapping portion;
Further, the toner supply member of the toner supply roller is composed of a large number of elastically bent hairs, and the axial width of the toner supply member is set shorter than the axial width of the groove overlapping portion, When the toner supply member is brought into contact with the image carrier, a predetermined number of bristles at both ends of the toner supply member are not formed in the groove closer to both ends of the developing roller than the first and second inclined groove independent forming portions. A developing device characterized by being elastically deflectable so as to reach the portion.   The first inclined groove in the groove overlapping portion and the third inclined groove in the first inclined groove independent forming portion are formed as continuous grooves, and the second inclined groove in the groove overlapping portion. 2. The developing device according to claim 1, wherein the first inclined groove and the fourth inclined groove in the second inclined groove independent forming portion are formed as continuous grooves.   3. The developing device according to claim 1, wherein each of the first to fourth inclined grooves is formed from a spiral groove.   4. The developing device according to claim 1, wherein each of the first and second inclined grooves is formed continuously or intermittently.   The predetermined number of third inclined grooves and fourth inclined grooves respectively formed in the first and second inclined groove independent forming portions are respectively formed at predetermined pitch intervals, and the first and second inclined grooves are formed. 5. The development according to claim 1, wherein each axial width of the single groove forming portion is set to be larger than the pitch interval between the third inclined groove and the fourth inclined groove. 6. apparatus. At least an image carrier on which an electrostatic latent image is formed, a developing roller that supplies toner for developing the electrostatic latent image to the image carrier, a toner supply roller that supplies toner to the developing roller, and the developing roller A developing device that includes at least a regulating blade that abuts to regulate the amount of toner on the developing roller; and a transfer device that transfers the toner image on which the electrostatic latent image on the image carrier is developed to a transfer medium. In at least the image forming apparatus provided,
The image forming apparatus according to claim 1, wherein the developing device is a developing device according to claim 1.

Images