JP4788223B2 - Elastic roller and developing device - Google Patents

Description

  The present invention relates to an image forming apparatus such as a copying machine, a printer, or a facsimile, and a developing device that performs development by supplying toner contained in the apparatus main body from the developer carrier to an image carrier on which a latent image is formed, and The present invention relates to an elastic roller used for supplying toner to the developer carrier in the developing device and for collecting the developed toner from the developer carrier.

  In an image forming apparatus such as a copying machine, a printer, or a facsimile, generally, the surface of an image carrier such as a photoconductor is charged by a charging device, and the surface of the charged image carrier is exposed according to image information by an exposure device. In this way, an electrostatic latent image is formed on the surface of the image carrier, and toner is supplied to the electrostatic latent image formed on the surface of the image carrier by a developing device for development.

  Here, as such a developing device, a two-component developing type developing device using toner and a carrier as a developer, and a one-component developing type developing device using only toner without using a carrier are known. It has been.

  For example, a developing device as shown in FIG. 1 is known as the one-component developing type developing device.

  Here, in this developing device, a toner t is accommodated in the apparatus main body 1 and a developer carrier 2 that rotates so as to face the image carrier P is provided, and a stirring member provided in the apparatus main body 1 3 is rotated to stir the toner t in the apparatus main body 1, and an elastic roller 4 is provided in the apparatus main body 1 so as to face the developer carrier 2. The elastic roller 4 is rotated. Thus, the toner t is supplied to the developer carrier 2.

  Then, the toner t supplied in this manner is held on the surface of the rotating developer carrier 2 and conveyed, and the regulating member 5 is brought into contact with the surface of the developer carrier 2 to convey the toner t to be conveyed. The toner t is charged, and the toner t thus regulated and charged is guided to the developing region facing the image carrier P by the developer carrier 2, and the toner t is guided to the image carrier P. The electrostatic latent image formed on the image carrier P is developed.

  Further, after developing the electrostatic latent image formed on the image carrier P in this manner, the toner t remaining without being developed is returned to the apparatus main body 1 through the sealant 6 by the developer carrier 2, and Thus, the remaining developed toner t is separated from the surface of the developer carrier 2 and a new toner t is supplied to the developer carrier 2.

  Here, as the elastic body roller 4, a roller having an elastic body layer 4 b made of urethane foam or the like is generally used on the outer periphery of the rotating shaft 4 a.

  However, in the case of the elastic roller 4 as described above, the ability to detach the developed toner t remaining on the developer carrier 2 and supply new toner t to the developer carrier 2 is not always sufficient. However, the developed toner t remaining on the developer carrying member 2 is not used again and is used for development many times, and the remaining developed toner t is used as the elastic body. When the elastic roller 4 is strongly pressed against the developer carrier 2 in order to be sufficiently separated from the developer carrier 2 by the roller 4, stress is applied to the toner t and the toner t is deteriorated. There are problems such as fogging on the formed image and scattering of the toner t.

  For this reason, in recent years, recesses and projections along the axial direction are alternately provided on the outer peripheral surface of the elastic roller in the circumferential direction, and the stress applied to the toner is reduced by the recesses. There has been proposed a toner in which the toner remaining on the developer carrying member is sufficiently separated by a portion so that new toner is appropriately supplied (see, for example, Patent Document 1).

However, when using an elastic roller having concave portions and convex portions along the axial direction alternately arranged on the outer peripheral surface as described above, toner accumulates in the concave portions and the toner aggregates. There is a problem that the toner thus deteriorated or the toner thus deteriorated is supplied to the developer carrying member, so that the formed image is still fogged or the toner is scattered.
JP 2000-56557 A

  An object of the present invention is to solve the above-described problems in a developing device that performs development by supplying toner contained in a main body of a device from a developer carrier to an image carrier on which a latent image is formed. Is.

  That is, in the present invention, the elastic roller used to supply toner to the developer carrying member and collect the developed toner from the developer carrying member is improved. The developed toner remaining on the body is appropriately removed and new toner is properly supplied to the developer carrier, and the toner is prevented from being deteriorated due to stress and stable development is stable. The challenge is to make it possible.

The first elastic roller according to the present invention is an elastic roller in which an elastic body layer is provided on the outer periphery of the rotating shaft, the outer peripheral shape of the elastic body layer is circular, and the rotating shaft is Since the outer peripheral shape is formed in a concavo-convex shape in the circumferential direction, portions having a large compressive deformation rate and small portions on the outer peripheral surface of the elastic layer are alternately formed in the circumferential direction. .
The second elastic roller is an elastic roller in which an elastic layer is provided on the outer periphery of the rotating shaft, and the outer peripheral shape of the elastic layer is circular and elastic with the rotating shaft. The resin part is provided between the body layer and the outer peripheral shape of the resin part is formed in a concavo-convex shape in the circumferential direction, so that the compression deformation rate on the outer peripheral surface of the elastic body layer is small and small. The portions are alternately formed in the circumferential direction.
Further, in the third elastic roller, in the elastic roller in which the first elastic body layer is provided on the outer periphery of the rotation shaft, the outer peripheral shape of the first elastic body layer is circular, A second elastic body layer having a compressive deformation rate smaller than that of the first elastic body layer is formed between the rotating shaft and the first elastic body layer, and the second elasticity Since the outer peripheral shape of the body layer is formed in a concavo-convex shape in the circumferential direction, the portion with a large compressive deformation rate and the small portion on the outer peripheral surface of the first elastic layer are alternately formed in the circumferential direction. It is characterized by being.

The first developing device according to the present invention includes a developer carrying member for developing the toner contained in the apparatus main body to the image carrying member on which the latent image is formed, and the developer carrying member. In the developing device provided with an elastic roller for supplying toner to the developer carrying member and for collecting the developed toner from the developer carrying member, the elastic roller rotates. An elastic body layer is provided on the outer periphery of the shaft. The outer peripheral shape of the elastic body layer is circular, and the elastic body layer is formed of two types of elastic body pieces having different compression deformation rates. A plurality of portions in the outer circumferential surface of the elastic layer are in contact with the developer carrying member alternately in the circumferential direction because the portions having a large compressive deformation rate are formed by being joined together in the direction. And
The second developing device is a developing device that performs development by supplying toner contained in the apparatus main body from the developer carrier to the image carrier on which the latent image is formed. Any one of the first to third elastic rollers was provided so as to be in contact with the agent carrier.

When the outer peripheral shape of the elastic layer provided on the outer periphery of the rotary shaft is circular like the first to third elastic rollers in the present invention, the concave and convex portions along the axial direction are formed on the outer peripheral surface in the circumferential direction. Thus, unlike the conventional elastic roller provided alternately, the toner is not accumulated in the concave portion and deteriorated.

Further, like the first to third elastic rollers in the present invention, when the portions having a large compressive deformation rate and the small portions on the outer peripheral surface of the elastic layer are alternately formed in the circumferential direction , the compressive deformation rate In the portion where the elastic body layer is large, the elastic layer is greatly deformed to reduce the stress applied to the toner. On the other hand, in the portion where the compression deformation ratio is small, the elastic body layer is hardly deformed and the development remaining on the developer carrying body is reduced. The later toner is appropriately removed.

Then, like the developing device in the present invention, a portion having a large compressive deformation rate and a small portion on the outer peripheral surface of the elastic layer so as to come into contact with the developer carrying member in the apparatus main body in which the toner is accommodated. Is provided with an elastic roller alternately formed in the circumferential direction, the toner is supplied to the developer carrying member by the elastic roller and the developed toner is collected from the developer carrying member as described above. In the portion where the compression deformation rate of the elastic roller is large, the stress applied to the toner is reduced, and in the portion where the compression deformation rate is small, the developed toner remaining on the developer carrying member is appropriately detached, and a new The toner is appropriately supplied to the developer carrying member, and good development can be stably performed.

  Next, an elastic roller according to an embodiment of the present invention and a developing device using the elastic roller will be specifically described with reference to the accompanying drawings. The elastic roller and the developing device according to the present invention are not limited to those shown in the following embodiments, and can be implemented with appropriate modifications within a range not changing the gist thereof.

  In the elastic body roller 40A of the embodiment shown in FIG. 2, an elastic body layer 42 is provided on the outer periphery of the rotating shaft 41, and the outer periphery shape of the elastic body layer 42 is circular. The rotary shaft 41 has concave portions 41a and convex portions 41b along the axial direction alternately formed on the outer peripheral surface thereof in the circumferential direction, and the outer peripheral shape thereof is uneven in the circumferential direction.

  Here, in this elastic roller 40A, the thickness of the elastic layer 42 at the convex portion 41b portion on the outer peripheral surface of the rotating shaft 41 is smaller than the thickness of the elastic layer 42 at the concave portion 41a. The compressive deformation rate in the normal direction on the outer peripheral surface of the elastic layer 42 corresponding to the convex portion 41b is smaller than the compressive deformation rate in the normal direction on the outer peripheral surface of the elastic layer 42 corresponding to the concave portion 41a. The portions having a large compressive deformation rate and the portions having a small compressive deformation rate are alternately formed in the circumferential direction on the outer peripheral surface of the elastic layer 42.

  Further, in the developing device of the embodiment using the elastic roller 40A, as shown in FIG. 3, the elasticity is provided so as to face the developer carrier 2 in the device main body 1 in which the toner t is accommodated. A body roller 40A is provided.

  Here, also in this developing apparatus, as in the developing apparatus shown in FIG. 1, the stirring member 3 provided in the apparatus main body 1 is rotated to stir the toner t in the apparatus main body 1 and the elasticity described above. The body roller 40A is rotated in the same direction as the developer carrier 2, and the elastic roller 40A and the developer carrier 2 are moved in opposite directions at the portion where the elastic roller 40A and the developer carrier 2 face each other. Thus, the toner t is supplied to the developer carrier 2.

  Then, the toner t supplied in this manner is held on the surface of the rotating developer carrier 2 and conveyed, and the regulating member 5 is brought into contact with the surface of the developer carrier 2 to convey the toner t to be conveyed. The toner t is charged, and the toner t thus regulated and charged is guided to the developing region facing the image carrier P by the developer carrier 2, and the toner t is guided to the image carrier P. The electrostatic latent image formed on the image carrier P is developed.

  Further, after developing the electrostatic latent image formed on the image carrier P in this manner, the toner t remaining without being developed is returned to the apparatus main body 1 through the sealant 6 by the developer carrier 2, and The developed toner t remaining on the developer carrier 2 is separated from the surface of the developer carrier 2 and the new toner t is supplied to the developer carrier 2 by the elastic roller 40A rotating as described above. I am doing so.

  Here, when the developed toner t remaining on the developer carrier 2 is separated from the surface of the developer carrier 2 by the elastic roller 40A, it corresponds to the convex portion 41b of the rotary shaft 41. In the portion of the elastic layer 42 where the compressive deformation rate is small, since the deformation of the elastic layer 42 is small, the developer carrier 2 is strongly pressed, and the toner t after development becomes the developer carrier. 2 is appropriately separated from the toner carrier 2 so that a new toner t is appropriately supplied to the developer carrier 2. On the other hand, in the portion of the elastic layer 42 where the compression deformation rate corresponding to the concave portion 41a of the rotating shaft 41 is increased, the elastic layer 42 is deformed, and the pressure applied to the developer carrier 2 is weakened. Stress applied to the toner t on the surface of the developer carrier 2 is reduced, and the toner t is prevented from deteriorating.

  Further, in the elastic body roller 40A, the outer peripheral shape of the elastic body layer 42 is a circular shape, so that a conventional concave portion and a convex portion along the axial direction are alternately provided on the outer peripheral surface in the circumferential direction. Unlike the elastic roller, the toner t does not accumulate and deteriorate in the recess.

  As a result, in the developing device in this embodiment, the developed toner t remaining on the developer carrier 2 is appropriately separated by the elastic roller 40A, and a new toner t is applied to the developer carrier 2. In addition to being supplied appropriately, the toner t is prevented from being deteriorated by applying stress or the like, and good development can be stably performed.

  In addition, the elastic body roller of this invention is not limited to the above, The elastic body rollers 40B-40E which concern on other embodiment are demonstrated based on an accompanying drawing.

  In the elastic roller 40B of the second embodiment shown in FIG. 4, concave portions 43a and convex portions 43b along the axial direction are alternately formed in the circumferential direction on the outer periphery of the rotating shaft 41 having a circular shape. A resin part 43 having an outer peripheral shape is formed, and an elastic layer 42 having a circular outer peripheral shape is formed on the outer periphery of the resin part 43.

  In the elastic roller 40B according to the second embodiment, the thickness of the elastic layer 42 at the convex portion 43b provided on the outer periphery of the resin portion 43 is equal to the elastic body at the concave portion 43a. The compressive deformation rate in the normal direction on the outer peripheral surface of the elastic layer 42 corresponding to the convex portion 41b is smaller than the thickness of the layer 42, and the normal deformation direction in the outer peripheral surface of the elastic layer 42 corresponding to the concave portion 41a is The compression deformation rate becomes smaller, and portions having a large compression deformation rate and small portions are alternately formed in the circumferential direction on the outer peripheral surface of the elastic body layer 42.

  In the elastic roller 40C of the third embodiment shown in FIG. 5, the elastic body is between the rotary shaft 41 having a circular shape and the elastic body layer 42 on the outer peripheral side having a circular outer peripheral shape. A second elastic layer 44 made of an elastic material having a hardness higher than that of the layer 42 and having a low compressive deformation rate is provided, and a concave portion 44a and a convex portion 44b along the axial direction are provided on the outer peripheral surface of the second elastic layer 44. Are alternately formed in the circumferential direction so that the outer peripheral shape of the second elastic layer 44 is uneven in the circumferential direction.

  In the elastic roller 40C according to the third embodiment, the convex portion 44b provided on the outer periphery of the second elastic layer 44 made of an elastic material having a high hardness and a low compressive deformation rate. The thickness of the elastic body layer 42 becomes thinner than the thickness of the elastic body layer 42 at the concave portion 44a, and the compressive deformation rate in the normal direction on the outer peripheral surface of the elastic body layer 42 corresponding to the convex portion 44b is reduced. The compressive deformation rate in the normal direction on the outer peripheral surface of the elastic body layer 42 corresponding to the concave portion 44a is smaller, and a portion having a large compressive deformation rate and a smaller portion on the outer peripheral surface of the elastic body layer 42 in the circumferential direction. They are formed alternately. In the case where the second elastic layer 44 is made of an elastic material having a lower hardness and a higher compressive deformation rate than the outer elastic layer 42, contrary to the above case, the convex portion 44b. The compressive deformation rate in the normal direction on the outer peripheral surface of the elastic layer 42 corresponding to is larger than the compressive deformation rate in the normal direction on the outer peripheral surface of the elastic layer 42 corresponding to the recess 44a.

In the elastic roller 40D of the fourth reference form shown in FIG. 6, an outer peripheral elastic layer 42 having a circular outer peripheral shape is formed on the outer periphery of the rotary shaft 41 having a circular shape. A plurality of gaps 45 extending in the axial direction are provided in the elastic layer 42 at appropriate intervals in the circumferential direction.

In the elastic roller 40D according to the fourth reference embodiment, the elastic layer 42 provided with the gap 45 extending in the axial direction as described above is an elastic body provided with no gap 45. It becomes easier to deform than the portion of the layer 42, and portions having a large compressive deformation rate and small portions are alternately formed in the circumferential direction on the outer peripheral surface of the elastic layer 42.

  In the elastic roller 40E of the fifth embodiment shown in FIG. 7, when the elastic layer 42 having a circular outer peripheral shape is formed on the outer periphery of the rotary shaft 41 having a circular shape, the compression deformation rate is reduced. Two different types of fan-shaped elastic body pieces 42a and 42b are alternately joined in the circumferential direction, and a portion having a large compressive deformation rate and a small portion are alternately formed in the circumferential direction on the outer circumferential surface of the elastic body layer 42. I try to do it.

  Even when the elastic rollers 40B to 40E in Embodiments 2 to 5 are used in the developing device instead of the elastic rollers 40A of Embodiment 1, the rollers of Embodiment 1 described above can be used. The same effect as that obtained when the elastic roller 40A is used can be obtained.

It is a schematic explanatory drawing of the conventional developing device. It is a schematic sectional drawing of the elastic body roller which concerns on the 1st Embodiment of this invention. It is a schematic explanatory drawing of the image development apparatus using the elastic body roller which concerns on said 1st Embodiment. It is a schematic sectional drawing of the elastic body roller which concerns on the 2nd Embodiment of this invention. It is a schematic sectional drawing of the elastic body roller which concerns on the 3rd Embodiment of this invention. It is a schematic sectional drawing of the elastic body roller which concerns on the 4th reference form of this invention. It is a schematic sectional drawing of the elastic body roller which concerns on the 5th Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Apparatus main body 2 Developer support body 3 Stirring member 5 Restriction member 6 Sealing material 40A-40E Elastic body roller 41 Rotating shaft 41a Rotating shaft recessed part 41b Rotating shaft convex part 42 Elastic body layer 42a, 42b Elastic body piece 43 Resin part 43a Concave portion of resin portion 43b Convex portion of resin portion 44 Second elastic layer 44a Concave portion of second elastic layer 44b Convex portion of second elastic layer 45 Gap portion P Image carrier t Toner

Claims (5)

  In the elastic roller in which the elastic layer is provided on the outer periphery of the rotating shaft, the outer peripheral shape of the elastic layer is circular, and the outer peripheral shape of the rotating shaft is formed in an uneven shape in the circumferential direction. Accordingly, the elastic roller is characterized in that portions having a large compressive deformation rate and small portions on the outer peripheral surface of the elastic layer are alternately formed in the circumferential direction.   In the elastic roller in which an elastic layer is provided on the outer periphery of the rotating shaft, the outer peripheral shape of the elastic layer is circular, and a resin portion is provided between the rotating shaft and the elastic layer. Since the outer peripheral shape of the resin part is formed in a concavo-convex shape in the circumferential direction, a portion with a large compressive deformation rate and a small portion on the outer peripheral surface of the elastic body layer are alternately formed in the circumferential direction. An elastic roller characterized by that.   In the elastic body roller provided with the first elastic body layer on the outer periphery of the rotation shaft, the outer periphery shape of the first elastic body layer is circular, and the rotation shaft and the first A second elastic body layer having a compressive deformation rate smaller than that of the first elastic body layer is formed between the elastic body layer and the outer peripheral shape of the second elastic body layer is uneven in the circumferential direction. The elastic roller is characterized in that portions having a large compressive deformation rate and small portions on the outer peripheral surface of the first elastic layer are alternately formed in the circumferential direction. A developer carrier that performs development by supplying toner contained in the apparatus main body to an image carrier on which a latent image is formed, and a developer carrier that is provided in contact with the developer carrier. In the developing device provided with an elastic roller that supplies toner to the developer and collects the developed toner from the developer carrying member, the elastic roller is provided with an elastic layer on the outer periphery of the rotating shaft. The outer peripheral shape of the elastic body layer is circular, and the elastic body layer is formed by joining a plurality of elastic body pieces in the circumferential direction in the form of two types of sectors having different compression deformation rates. A developing device characterized in that a portion having a large compressive deformation rate and a portion having a small compressive deformation rate on the outer peripheral surface of the elastic layer are in contact with the developer carrier alternately in the circumferential direction. In a developing device that performs development by supplying toner contained in the apparatus main body to the image carrier on which the latent image is formed from the developer carrier, the developer body is in contact with the developer carrier. A developing device comprising the elastic roller according to any one of claims 1 to 3.

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