JP2007240795A - Developing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a developing device capable of stabilizing the detecting precision of a sensor without increasing the size of the device and also stabilizing image quality. <P>SOLUTION: The rotation shaft 7a of a first stir screw 7 is approximately perpendicular to a side wall 5a in a casing 5. A cleaning member 1 includes: a first wound spring part 1a fixed to the side of the detecting face 13a rather than to the rotation shaft 7a of a first stir screw 7 and elastically deformable in a direction parallel to a detecting face 13a; and a first cleaning part 1c connected to the first wound spring 1a and slid against the detecting face 13a as the first stir screw 7 rotates. The length from the shaft center of the rotation shaft 7a to the leading end of a first cleaning part 1c is greater than that from the shaft center of the rotation shaft 7a to the internal wall face of the casing 5. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a developing device that includes a sensor that detects the amount of developer, and more particularly to a developing device that includes a cleaning member that cleans a detection surface of the sensor.

  In order to maintain the quality of images created by image forming apparatuses such as copiers, printers, and facsimile machines, the developer is appropriately replenished to the developing device according to the environmental temperature, environmental humidity, etc. (Or toner concentration in the developer) needs to be adjusted. For this reason, the developing device is usually provided with a detection sensor for measuring the developer amount (or toner concentration).

  However, if the developer containing toner adheres to the measurement location (for example, the detection surface) of the detection sensor, the accurate toner amount inside the developing device cannot be measured. Therefore, various developing devices have been proposed in which a cleaning member is provided in the stirring screw inside the developing device, and the detection surface is cleaned according to the rotation of the stirring screw.

For example, in the developing device of Patent Document 1, the coil portion of the coil spring is attached to the rotating shaft of a rod-shaped stirring screw, the sliding contact portion extending from one end of the coil spring is brought into sliding contact with the detection surface, and the detection surface of the sensor is set. Cleaning.
Japanese Utility Model Publication 1-283148

  However, in the developing device shown in Patent Document 1, since the detection surface is cleaned using a linear sliding contact portion, when the developer having deteriorated fluidity stays in the vicinity of the sensor, the staying developer is improved. It cannot be dispersed. In particular, in the case of the one-component developing method, if the fluidity of the toner in the developer changes depending on the environmental conditions and the period of use, and it becomes easy to stay (deposit) in the vicinity of the detection surface, there may be a problem of causing false detection of the sensor. .

  Further, when the sensor is attached to the detection surface away from the stirring screw, a strong pressure is applied even with a small amount of toner, so that it is detected that there is sufficient toner even though the amount of toner in the developing machine is small. On the other hand, if it is too close to the stirring screw, the toner will move poorly, and the force in the direction of pressing against the development side will not work, and there will be a minute gap in the part where the wire for cleaning the sensor detection surface has passed. Then, no toner is detected despite the presence of toner.

  This phenomenon appears remarkably when the toner deteriorates and a surface treatment agent such as titanium oxide or silica is deeply embedded in the toner surface. If the surface treatment agent is deeply embedded in the toner, the fluidity is deteriorated and becomes a gel rather than a fluid. In particular, this phenomenon appears remarkably in the case of pulverized toner. Therefore, in order to extend the life of the developer, it is preferable that the detection sensor is not too close to the stirring screw.

  When it is detected that the toner is low, an image defect occurs due to a thin layer formation defect of the developer on the developing roller. If it is detected that there is not enough toner, toner is excessively replenished, which may cause rapid deterioration of the toner, and the developing device may be locked or damaged.

  Therefore, the mounting position of the sensor is optimized in consideration of space and the like in the lateral direction and the height direction so that the above problem does not occur. Conventionally, the distance from the shaft center of the stirring screw to the farthest portion of the wire portion is formed to be shorter than the distance from the shaft center of the stirring screw to the inner wall surface of the developing housing. Therefore, as a result of optimizing the mounting position of the sensor, the distance from the stirring screw to the farthest part of the wire part may be shorter than the distance from the stirring screw to the farthest part of the detection surface of the sensor. In this case, an uncleaned area that cannot be cleaned occurs on the detection surface of the sensor.

  Normally, it is practical even if there are some uncleaned areas. However, when the toner deteriorates and the fluidity deteriorates, the toner sticks to the detection surface of the uncleaned area in a block shape, causing detection failure. Such a detection failure leads to a failure to form a thin layer of developer on the developing roller, and as a result, an image failure occurs.

  To eliminate the uncleaned area, the distance from the stirring screw to the farthest part of the wire part for cleaning may be increased. However, the tip of the wire part is strongly rubbed against the inner wall surface of the developing housing, and the toner aggregates The agglomerates are caught in the thin layer forming part and white streaks are generated, or black spots due to the agglomerates and white spots in the transfer part (so-called firefly phenomenon) occur. In order to suppress toner aggregation, the diameter of the wire portion may be reduced. However, a durability problem may occur, and if the usage time is increased, the wire portion may be damaged or deformed due to fatigue. If the radius of the inner wall surface of the developing housing is increased, such a problem does not occur, but the apparatus becomes larger.

  The present invention has been made to solve the above-described problems, and provides a developing device capable of stabilizing the detection accuracy of the sensor and stabilizing the image quality without increasing the size of the device. It is intended to do.

  The developing device according to the present invention includes a housing for storing the developer, a detecting unit provided on a side surface in the housing for detecting the amount of the developer, a stirring member for stirring the developer in the housing, and the stirring And a cleaning member that cleans the detection surface of the detection means as the member rotates, wherein the rotation shaft of the stirring member is substantially perpendicular to the side surface in the housing, and the cleaning member Is fixed to the detection surface side of the rotating shaft of the stirring member and is elastically deformable in a direction parallel to the detection surface, and connected to the elastic portion to the detection surface as the stirring member rotates. A cleaning portion that is in sliding contact, and a length from an axis of the rotating shaft to a tip portion of the cleaning portion is longer than a length from an axis of the rotating shaft to an inner wall surface of the casing.

  In addition, the developing device according to the present invention includes a housing for storing the two-component developer, a detection unit that is provided on a side surface in the housing and detects a mixing ratio of the toner and the carrier of the two-component developer, A developing device, comprising: a stirring member that stirs the developer in the housing; and a cleaning member that cleans the detection surface of the detection means as the stirring member rotates. An elastic portion that is substantially perpendicular to a side surface of the body, and the cleaning member is fixed to the detection surface side with respect to a rotation shaft of the stirring member and elastically deformable in a direction parallel to the detection surface; and the elastic portion And a cleaning part that is in sliding contact with the detection surface as the stirring member rotates, and the length from the axis of the rotating shaft to the tip of the cleaning part is from the axis of the rotating shaft to the housing. It is longer than the length to the inner wall of the body.

  According to these configurations, the rotation shaft of the stirring member is substantially perpendicular to the side surface in the casing, and the cleaning member is fixed to the detection surface side of the rotation shaft of the stirring member by the elastic portion, and is on the detection surface. The elastic member can be elastically deformed in a parallel direction, and is brought into sliding contact with the detection surface as the stirring member rotates by the cleaning unit connected to the elastic unit. And the cleaning member is formed so that the length from the axial center of a rotating shaft to the front-end | tip part of a cleaning part may become longer than the length from the axial center of a rotating shaft to the inner wall face of a housing | casing.

  Therefore, the length from the axis of the rotating shaft to the tip of the cleaning unit is longer than the length from the axis of the rotating shaft to the inner wall surface of the housing. It will be in sliding contact with the inner wall surface. At this time, the force applied to the cleaning portion is absorbed by the elastic deformation of the elastic portion, and an excessive load on the cleaning portion is reduced, so that toner agglomeration is prevented and the apparatus is not enlarged. The detection accuracy of the sensor can be stabilized, and the image quality can be stabilized.

  In the developing device, the stirring member includes a support member provided closer to the detection surface than the rotation shaft, and the elastic portion includes a first winding spring portion inserted into the support member; An end portion of the first coil spring portion and a locking portion that is locked to the rotating shaft or the support member, and the cleaning portion extends in a direction substantially perpendicular to the rotating shaft. It is preferable that the first end of the first coil spring portion is configured.

  According to this configuration, the first winding spring portion is inserted into the support member provided on the detection surface side with respect to the rotating shaft of the stirring member, and one end of the first winding spring portion is bent and formed. The part is locked to the rotating shaft or the support member. A cleaning part is comprised by the other end of the 1st winding spring part extended in the direction substantially perpendicular | vertical to a rotating shaft. Therefore, since the force applied to the cleaning part is absorbed by the first coil spring part, the first coil spring part can be prevented from being damaged or deformed, and the life of the apparatus can be extended.

  In the developing device, the cleaning unit may include a first cleaning unit configured by the other end of the first winding spring unit extending in a direction substantially perpendicular to the rotation shaft, and a first cleaning unit. A second cleaning portion formed by bending the tip substantially perpendicular to the detection surface of the detection means and further bending the tip substantially perpendicularly to the first cleaning portion in a direction having a predetermined angle; It is preferable that the cleaning part includes a third cleaning part formed by bending the front end of the cleaning part substantially perpendicularly to the detection surface.

  According to this configuration, the first cleaning unit is configured by the other end of the first coil spring portion that extends in a direction substantially perpendicular to the rotation axis, and the second cleaning unit detects the tip of the first cleaning unit of the detection unit. It is formed by bending substantially perpendicular to the detection surface and further bending the tip of the first cleaning portion in a direction having a predetermined angle with the first cleaning portion, and the third cleaning portion extends the tip of the second cleaning portion in the direction of the detection surface. It is formed by bending substantially vertically.

  Therefore, the first cleaning unit, the second cleaning unit, and the third cleaning unit can more effectively disperse the developer staying in the vicinity of the detection surface, and can stabilize the detection accuracy of the sensor. .

  In the developing device, the distance from the axis of the rotation shaft to the inner wall surface of the housing may be determined from the radius of the rotation shaft and the edge of the detection surface of the detection unit closest to the axis. It is preferable that the distance to the edge of the detection surface farthest from the axis and the distance obtained by adding the thickness between the rotating shaft and the detection means is shorter.

  According to this configuration, the distance from the axis of the rotating shaft to the inner wall surface of the housing is such that the radius of the rotating shaft and the detection surface farthest from the edge of the detecting surface of the detecting means closest to the axis are detected. Since it is formed so as to be shorter than the distance obtained by adding the length to the edge and the thickness between the rotating shaft and the detection means, the apparatus can be reduced in size.

  The developing device may further include support means for supporting the rotating shaft of the stirring member, and the support means is provided on a side surface of the casing that is the same as the detection surface. It is preferable to protrude inward or outward.

  According to this configuration, the support means for supporting the rotating shaft of the stirring member is provided on the side surface of the same casing as the detection surface, and protrudes inward or outward with respect to the side surface. Therefore, even when the supporting means for supporting the rotating shaft of the stirring member is protruded inward or outward with respect to the side surface of the housing, the detection accuracy of the sensor can be obtained by configuring the cleaning member as described above. Can be stabilized. In particular, when the support means is projected outward, the support means needs a certain amount of thickness, so there is a limit to bringing the detection means close to the rotating shaft. However, by configuring the cleaning member as described above, detection is possible. Even if the means is slightly separated from the rotating shaft, the detection surface can be reliably cleaned. Further, when the supporting means is protruded inward, the apparatus is usually enlarged because the detecting means is arranged away from the rotation shaft, but the apparatus is enlarged by configuring the cleaning member as described above. The detection surface can be surely cleaned.

  In the developing device, the detection unit is preferably a piezoelectric sensor. According to this configuration, by using the piezoelectric sensor as the detecting means, the presence of the developer can be detected more accurately, and the amount of developer in the developing device can be adjusted to an appropriate amount.

  According to the present invention, the force applied to the cleaning portion is absorbed by the elastic deformation of the elastic portion, and an excessive load on the cleaning portion is reduced, so that toner agglomeration is prevented and the apparatus is enlarged. Without this, the detection accuracy of the sensor can be stabilized and the image quality can be stabilized.

  A developing device according to an embodiment of the present invention will be described below with reference to the drawings.

  FIG. 1 is a diagram showing a configuration of a printer using a developing device according to the present invention. The printer shown in FIG. 1 is an example of an image forming apparatus. The printer 100 includes a developing device 101, a photosensitive drum 102, a charging unit 103, an image writing unit 104, a toner storage unit 105, a transfer unit 106, a cleaning unit 107, a recording paper storage unit 108, a conveyance unit 109, and a fixing unit 110. And a paper discharge unit 111.

  The photosensitive drum 102 is formed, for example, by laminating a photosensitive layer on an aluminum drum, and the charging unit 103 charges the surface. Then, an electrostatic latent image in which charging is attenuated is formed on the surface that has received the laser beam from the image writing unit 104. The photosensitive layer is not particularly limited, but for example, amorphous silicon (a-Si) having excellent durability is preferable.

  The charging unit 103 charges the surface of the photosensitive drum 102 by discharging (for example, corona discharge). For example, the charging unit 103 has a thin wire or the like, and uses this as an electrode to discharge when a high voltage is applied.

  The image writing unit 104 irradiates the photosensitive drum 102 with a light beam (for example, a laser beam) based on the image data, and forms an electrostatic latent image on the photosensitive drum 102. Note that the image data is transmitted from a personal computer (PC) (not shown).

  The developing device 101 attaches toner to the electrostatic latent image on the photosensitive drum 102 to form a toner image. In the present embodiment, as the developer contained in the developing device 101, for example, a magnetic one-component developer composed only of a magnetic toner can be cited. The toner is a pulverized toner, and has been subjected to an external addition process for improving fluidity. Details of the developing device 101 will be described later.

  The toner storage unit 105 stores a developer (hereinafter simply referred to as toner) and supplies the toner to the developing device 101 when the toner in the developing device 101 is insufficient. The transfer unit 106 transfers the toner image formed on the surface of the photosensitive drum 102 to the recording paper conveyed by the conveyance unit 109.

  The cleaning unit 107 removes the toner (residual toner) remaining on the surface of the photosensitive drum 102 after the toner image is transferred (transferred) to the recording paper. For example, the cleaning unit 107 includes a blade material that is in line contact with the longitudinal direction of the photosensitive drum 102. The recording paper storage unit 108 stores recording paper (such as paper and OHP) on which an image (toner image) is finally printed, and sends the recording paper to the transport unit 109.

  The transport unit 109 transports the recording paper from the recording paper storage unit 108 to the paper discharge unit 111. The fixing unit 110 melts the toner image in a powder state by applying energy such as heat and pressure, and fixes the toner image transferred to the recording paper. The paper discharge unit 111 stores recording paper that has passed through the fixing unit 110, that is, recording paper on which a toner image has been printed and discharged to the outside of the apparatus.

  In such a printer 100, the image writing unit 104 emits a laser beam (light beam) to the photosensitive drum 102 based on the image data, so that the electrostatic latent image based on the image data is transferred to the photosensitive drum. It is formed on the surface of 102. Thereafter, the developing device 101 attaches toner to the electrostatic latent image (forms a toner image), and the transfer unit 106 transfers the toner image to the recording paper. Next, the fixing unit 110 applies heat or the like to the recording paper on which the toner image is transferred, and fixes the toner image.

  Next, the configuration of the developing device 101 will be described. 2 is a perspective view showing a schematic configuration of the developing device according to the present invention, FIG. 3 is a side view showing a schematic configuration of the developing device shown in FIG. 2, and FIG. 4 is a developing device shown in FIG. It is the front view which looked at from the upper part. 2 is expressed excluding the lid portion (cover portion) for the sake of convenience, and FIG. 4 mainly expresses the first stirring screw described later.

  FIG. 5 is an enlarged view of the end of the first stirring screw shown in FIG. 6 is a cross-sectional view taken along line AA in FIG. FIG. 7 is a diagram showing a cross section in the axial direction of the end portion of the first stirring screw shown in FIG. 5. FIG. 8 is a view of the cleaning member 1 viewed from the direction of arrow C in FIG. 5, and FIG. 9 is a view of the cleaning member 1 viewed from the direction of arrow D in FIG.

  As shown in these drawings, the developing device 101 includes a casing (housing) 5, a cover (housing) 6, a first stirring screw 7, a second stirring screw 8, a developing roller 11, a regulating blade 12, and toner amount detection. A sensor 13 is provided.

  The casing 5 stores the toner and accommodates the first stirring screw 7 and the like. And in this casing 5, the 1st storage chamber 15 and the 2nd storage chamber 16 which were divided by the partition plate 9 are formed. A first stirring screw 7 is disposed in the first storage chamber 15, and a second stirring screw 8 is disposed in the second storage chamber 16. The cover 6 seals the toner stored in the casing 5 so as not to leak to the outside. The casing 5 and the cover 6 together constitute a housing of the developing device 101.

  The first stirring screw 7 conveys the toner stored in the first storage chamber 15 in the direction of arrow P in FIG. The second agitating screw 8 agitates the toner conveyed to the second storage chamber 16, conveys it in the direction of arrow Q in FIG. 2 and supplies it to the developing roller 11. Further, the toner sent by the second stirring screw 8 is strongly pressed against the side wall 5 a by the partition plate 9.

  The first agitating screw 7 and the second agitating screw 8 have a configuration in which spiral wings 7b and 8b are provided around the rotation shafts 7a and 8a, respectively, and the casing 5 is parallel to each other. It is pivotally supported so that it can rotate. As shown in FIG. 4, the end 71 of the rotating shaft 7a of the first stirring screw 7 protrudes from the side wall 5a and is inserted into the protrusion 5b formed on the side wall 5a. The protrusion 5b is provided on the side wall 5a of the casing 5 that is the same as the detection surface 13a, protrudes outward with respect to the side wall 5a, and rotatably supports the rotation shaft 7a of the first stirring screw 7. In addition, in this embodiment, although the protrusion part 5b protrudes outside with respect to the side wall 5a of the casing 5, this invention is not specifically limited to this, It protrudes inside with respect to the side wall 5a of the casing 5. Also good.

  Thus, the protrusion 5b that supports the rotating shaft 7a of the first stirring screw 7 is provided on the side wall 5a of the casing 5 that is the same as the detection surface 13a, and protrudes inward or outward with respect to the side wall 5a. Yes. Therefore, even when the protruding portion 5b that supports the rotating shaft 7a of the first stirring screw 7 is protruded inward or outward with respect to the side wall 5a of the casing 5, the cleaning member 1 is configured as described later. As a result, the detection accuracy of the toner amount detection sensor 13 can be stabilized.

  In particular, when the protruding portion 5b is protruded to the outside, the protruding portion 5b needs a certain amount of thickness, so there is a limit in bringing the toner amount detection sensor 13 close to the rotating shaft 7a. By configuring this, even if the toner amount detection sensor 13 is slightly separated from the rotation shaft 7a, the detection surface 13a can be reliably cleaned. Further, when the protruding portion 5b is protruded inward, the apparatus is usually enlarged because the toner amount detection sensor 13 is disposed away from the rotation shaft. However, by configuring the cleaning member 1 as described later, the apparatus The detection surface 13a can be reliably cleaned without increasing the size.

  In addition, a regulating portion 74 that regulates the amount by which the end portion 71 enters the protruding portion 5 b is formed on the rotating shaft 7 a of the first stirring screw 7. The diameter of the restricting portion 74 is smaller than the diameter of the rotating shaft 7 a and larger than the diameter of the end portion 71.

  The developing roller 11 rotates according to the rotation of the photosensitive drum 102 (see FIG. 1), thereby supplying toner to the photosensitive layer of the photosensitive drum 102. In the case of a developing device using magnetic toner, a magnet roller having a magnetic field generating member (not shown) made of a permanent magnet fixed on the inner surface is used as the developing roller 11. A toner thin layer is formed by attaching (carrying) toner to the surface of the developing roller 11 by the magnetic force of the magnetic field generating member. On the other hand, in the case of a developing device using non-magnetic toner, a rubber roller or the like is used as the developing roller 11.

  The developing roller 11 is rotatably supported on the casing 5 in a state parallel to the first stirring screw 7 and the second stirring screw 8. The first stirring screw 7, the second stirring screw 8, and the developing roller 11 are rotationally driven by a driving unit (not shown).

  The regulating blade 12 regulates the amount of toner supplied to the photosensitive drum 102. In the case of a developing device that uses magnetic toner, the regulating blade 12 is made of, for example, SUS (stainless steel) such as SUS430. A magnetic field generating member provided opposite to the tip of the regulating blade 12 generates a magnetic field between the developing roller 11 and the regulating blade 12, and not only the distance between the regulating blade 12 and the developing roller 11 but also the magnetic field. The amount of toner adhering to the developing roller 11 is strictly regulated by the strength. This makes it possible to form a thin toner layer of several tens of microns.

  The toner amount detection sensor 13 is composed of, for example, a piezoelectric sensor, and detects the amount of toner (or toner concentration or the like) stored in the casing 5. Piezoelectric sensors use the property of piezoelectric elements that generate a voltage proportional to the magnitude of an impact or vibration from the outside, taking out the impact or vibration as an electrical signal. Has features. The toner amount detection sensor 13 is provided on the side wall 5 a of the casing 5 in the vicinity of the communication between the first storage chamber 15 and the second storage chamber 16. The toner amount detection sensor 13 is provided such that a detection surface 13a described later faces the first storage chamber 15 and the second storage chamber 16, that is, the inner side.

  When the developer is sufficiently stored in the first storage chamber 15 and the second storage chamber 16, the detection surface 13a of the toner amount detection sensor 13 is applied with a certain pressure by the developer, so that the toner is It is detected that it is sufficiently stored. On the other hand, when a sufficient amount of toner is not stored in the first storage chamber 15 and the second storage chamber 16, the toner amount detection sensor 13 is not applied with a certain pressure or more by the toner. In such a case, the toner amount detection sensor 13 detects that the toner amount is not sufficient.

  When the toner amount detection sensor 13 detects that the toner is sufficiently stored, the detection signal is transmitted to a control unit such as a CPU provided in the image forming apparatus, and the control unit stores the toner storage unit 105 (FIG. 1). The supply of toner into the developing device 101 is stopped. When the toner amount in the developing device 101 decreases and the toner does not contact the detection surface 13a, the control unit resumes the supply of toner from the toner storage unit 105.

  In the above description, the piezoelectric sensor is used. However, the sensor used in the developing device 101 of the present invention is not limited to the piezoelectric sensor. For example, an optical sensor or a magnetic sensor may be used. Further, the toner used in the developing device 101 of the present invention is not particularly limited, and may be one-component toner or two-component toner, and may be magnetic or non-magnetic. .

  In general, in the case of a two-component developer, T / C (mixing ratio of toner and carrier) is detected using a magnetic permeability sensor. Therefore, the developing device 101 may include a magnetic permeability sensor that detects the mixing ratio of the toner of the two-component developer and the carrier in place of the toner amount detection sensor 13. The magnetic permeability sensor detects a certain amount of toner adhering to the carrier as a change in inductance by allowing a certain amount of developer in the developing device to pass through a flow path provided with a coil of a resonance circuit.

  Here, a characteristic configuration of the developing device 101 of the present invention will be described. FIG. 5 is an enlarged view of an end portion of the first stirring screw shown in FIG. 6 is a cross-sectional view taken along line AA in FIG. FIG. 7 is a diagram showing a cross section in the axial direction of the end portion of the first stirring screw shown in FIG. 5. FIG. 8 is a view of the cleaning member 1 viewed from the direction of arrow C in FIG. 5, and FIG. 9 is a view of the cleaning member 1 viewed from the direction of arrow D in FIG.

  In the developing device 101, a cleaning member 1 including a first winding spring portion 1a, a locking portion 1b, and a first cleaning portion 1c is provided on a rotating shaft 7a of the first stirring screw 7. Since the cleaning member 1 rotates with the rotation of the first stirring screw 7, the detection surface 13a of the toner amount detection sensor 13 is cleaned by the first cleaning unit 1c. The tip of the first cleaning part 1c is bent at a right angle three times in total, once in the direction opposite to the detection surface 13a, once in the direction of the first winding spring part 1a, and once in the direction of the first cleaning part 1c. A bent portion 17, a second cleaning portion 18, and a third cleaning portion 19 are formed.

  The 1st stirring screw 7 is provided with the supporting member 7c provided in the detection surface 13a side rather than the rotating shaft 7a. The support member 7c is a substantially columnar member formed integrally with the rotation shaft 7a and parallel to the axis of the rotation shaft 7a.

  The cleaning member 1 includes a first wound spring portion 1a, a locking portion 1b, and a first cleaning portion 1c that are integrally formed using a single metal wire (spring material) having elasticity. The wire diameter of the wire is preferably in the range of 0.1 mm to 0.6 mm. If the wire diameter of the wire becomes thinner than this range, there is a risk that deformation, breakage, malfunction due to toner resistance, etc. may occur. Further, when the wire diameter of the wire becomes thicker than this range, toner aggregation tends to occur. In addition, the wire diameter of a more preferable wire is in the range of 0.2 mm to 0.4 mm. The wire material is preferably a spring stainless steel wire.

  The first winding spring portion 1a is a member for attaching the cleaning member 1 to a position away from the rotation shaft 7a toward the detection surface 13a, and is formed by winding a wire in a coil shape. It penetrates. The expansion and contraction direction of the first coil spring portion 1 a is a direction perpendicular to the detection surface 13 a of the toner amount detection sensor 13 and is the same as the axial direction of the first stirring screw 7.

  As shown in FIG. 6, a groove 72 is formed in the support member 7c in a direction perpendicular to the axis of the rotation shaft 7a. Further, a groove 73 is formed in the outer peripheral portion of the restricting portion 74 of the rotating shaft 7a in the same direction as the groove 72 of the support member 7c.

  The locking part 1 b transmits the rotational force of the first stirring screw 7 to the cleaning member 1. As shown in FIG. 9, one end of the winding spring portion 1a is bent in a direction perpendicular to the tangential direction. Then, one end of the winding spring portion 1a is fitted into a groove 72 formed in the support member 7c and a groove 73 formed in the rotary shaft 7a, and the tip is locked to the rotary shaft 7a. . That is, the 1st coiled spring part 1a and the latching | locking part 1b fix the cleaning member 1 to the support member 7c and the rotating shaft 7a.

  The first cleaning portion 1c is formed by bending the other end of the first coil spring portion 1a in the axial direction of the rotating shaft 7a and then bending it in a direction substantially perpendicular to the rotating shaft 7a. The first cleaning unit 1 c is formed in a pin (wire) shape having a length that includes the entire area (diameter) of the detection surface 13 a from the rotation shaft 7 a, and is in sliding contact with the detection surface 13 a of the toner amount detection sensor 13. The first cleaning part 1c is pushed (pressed) toward the side wall 5a by the urging force of the first winding spring part 1a. As a result, the 1st cleaning part 1c is arranged near side wall 5a of casing 5 so that detection surface 13a can be slidably contacted.

  The cleaning member 1 has a length from the axis of the rotation shaft 7 a of the first stirring screw 7 to the tip of the first cleaning unit 1 c from the length from the axis of the rotation shaft 7 a to the inner wall surface of the casing 5. Is also formed to be long.

  Further, the tip of the first cleaning part 1c is bent substantially perpendicularly in the direction opposite to the detection surface 13a to form a bent part 17, and the tip of the bent part 17 is bent substantially perpendicularly to the direction of the winding spring part 1a. Two cleaning portions 18 are formed. With this configuration, when the cleaning member 1 rotates in the direction of arrow B in FIG. 3 along with the rotation of the rotating shaft 7a, the first cleaning unit 1c is in sliding contact with the detection surface 13a and the second cleaning unit 18 is bent from the detection surface 13a. Since the first cleaning portion 1c scrapes off the developer on the detection surface 13a and the second cleaning portion 18 generates toner slightly away from the detection surface 13a because the first cleaning portion 1c passes through a position separated by the length of the portion 17. Can effectively break the bridge.

  Moreover, as shown in FIG.3 and FIG.8, the 1st cleaning part 1c and the 2nd cleaning part 18 are not mutually parallel, but are the position of a twist. When the 1st cleaning part 1c and the 2nd cleaning part 18 are made parallel, the space | interval of the 1st cleaning part 1c and the 2nd cleaning part 18 becomes narrow, and the 1st cleaning part 1c, the bending part 17, and 2nd There is a possibility that the toner forms a bridge in the U-shaped portion surrounded by the cleaning unit 18.

  When the cleaning member 1 rotates in this state, toner in a range where the U-shaped portion passes is removed at a time, and the toner amount is detected without applying pressure to the detection surface 13a even though the toner amount is sufficient. There is a possibility that the sensor 13 erroneously detects that the toner is insufficient. On the other hand, when the first cleaning unit 1c and the second cleaning unit 18 are in a twisted position, the gap between the first cleaning unit 1c and the second cleaning unit 18 is widened, so that it is difficult to form a toner bridge. Further, erroneous detection of the toner amount detection sensor 13 can be prevented.

  Furthermore, in this embodiment, since the rotation direction of the cleaning member 1 is the arrow B direction, as shown in FIG. 3, the second cleaning unit 18 is positioned upstream of the bent portion 17 in the rotation direction (arrow B direction). is doing. The second cleaning unit 18 may be arranged on the downstream side in the rotation direction, but since the resistance of the toner is received during the rotation of the cleaning member 1, foreign matters attached to the tip of the second cleaning unit 18 are difficult to come off, It is preferable to arrange the second cleaning unit 18 so as to be on the upstream side in the rotational direction as in the present embodiment.

  Furthermore, in the present embodiment, the third cleaning portion 19 is formed by further bending the tip of the second cleaning portion 18 of the cleaning member 1 substantially perpendicularly in the direction of the first cleaning portion 1c. A part of the toner conveyed in the direction of the arrow Q in the second storage chamber 16 is supplied to the developing roller 11 as described above, but most of the toner is supplied from the gap between the partition plate 9 and the side wall 5a to the first storage chamber. 15 is transported again. At this time, the toner moves to the first storage chamber 15 so as to be pressed along the side wall 5a.

  Therefore, the toner adheres to the inner surface of the side wall 5 a so as to incline from the second storage chamber 16 toward the first storage chamber 15. Therefore, when the cleaning member 1 rotates, the third cleaning portion 19 is formed at a position that passes the first stirring screw 7 side rather than the end portion of the toner amount detection sensor 13 on the second stirring screw 8 side, whereby the toner is detected. The toner adhering to the vicinity of the end of the amount detection sensor 13 on the first stirring screw 7 side can be efficiently scraped off, and there is no possibility of damaging the detection surface 13 a at the tip of the third cleaning unit 19.

  The distance from the axis of the rotating shaft 7a to the inner wall surface of the casing 5 is determined by the radius of the end 71 of the rotating shaft 7a of the first stirring screw 7, the diameter of the detection surface 13a of the toner amount detecting sensor 13, and the rotation. It is formed to be shorter than the distance obtained by adding the thickness between the shaft 7a and the toner amount detection sensor 13. For example, the radius of the end 71 of the rotation shaft 7a of the first stirring screw 7 is 1.5 mm, the diameter of the detection surface 13a of the toner amount detection sensor 13 is 11 mm, and the rotation shaft 7a, the toner amount detection sensor 13, Is 2 mm, the distance from the axis of the rotating shaft 7 a to the inner wall surface of the casing 5 is 12 mm (<1.5 mm + 11 mm + 2 mm).

  Thus, the toner amount detection in which the distance from the shaft center of the rotating shaft 7a of the first stirring screw 7 to the inner wall surface of the casing 5 is closest to the radius of the end 71 of the rotating shaft 7a and the shaft center of the rotating shaft 7a. The distance from the edge of the detection surface 13a of the sensor 13 to the edge of the detection surface 13a farthest from the axis and the distance between the rotation shaft 7a and the thickness of the toner amount detection sensor 13 are shorter. Therefore, the apparatus can be downsized.

  Depending on the configuration of the developing device, there may be no thickness between the rotating shaft 7a and the toner amount detection sensor 13. In this case, the distance from the shaft center of the rotating shaft 7a to the inner wall surface of the casing 5 is the toner amount detection sensor closest to the radius of the end 71 of the rotating shaft 7a of the first stirring screw 7 and the shaft center of the rotating shaft 7a. You may form so that it may become shorter than the distance which added the length from the edge part of 13 detection surfaces 13a to the edge part of the detection surface 13a furthest to an axial center. In addition, the detection surface 13a of the toner amount detection sensor 13 in the present exemplary embodiment is circular, but the present invention is not particularly limited thereto, and may be other shapes such as a quadrangular shape, a polygonal shape, and an elliptical shape. Good.

  In the present embodiment, the casing 5 and the cover 6 correspond to an example of a casing, the toner amount detection sensor 13 corresponds to an example of a detection unit, and the first stirring screw 7 corresponds to an example of a stirring member, and cleaning. The member 1 corresponds to an example of a cleaning member, the support member 7c corresponds to an example of a support member, the first winding spring portion 1a and the locking portion 1b correspond to an example of an elastic portion, and the first cleaning portion 1c cleans. The first winding spring portion 1a corresponds to an example of the first winding spring portion, the locking portion 1b corresponds to an example of the locking portion, and the first cleaning portion 1c corresponds to the first cleaning portion. The second cleaning unit 18 corresponds to an example of a second cleaning unit, the third cleaning unit 19 corresponds to an example of a third cleaning unit, and the protrusion 5b corresponds to an example of a support means.

  Here, the operation of the cleaning member 1 will be described. FIG. 10 is a diagram for explaining the operation of the cleaning member.

  As the first stirring screw 7 rotates, the cleaning member 1 rotates in the direction of arrow B. When the cleaning member 1 passes through the detection surface 13a, the developer staying in the vicinity of the detection surface 13a is scraped off by the first cleaning unit 1c. The cleaning member 1 contacts the inner wall surface perpendicular to the side wall 5 a of the casing 5. As described above, the cleaning member 1 has a length from the axis of the rotating shaft 7a of the first stirring screw 7 to the tip of the first cleaning unit 1c from the axis of the rotating shaft 7a to the inner wall surface of the casing 5. It is formed to be longer than the length of. Therefore, when the tip of the cleaning part 1c comes into contact with the inner wall surface, the first winding spring part 1a is elastically deformed and slidably contacts the inner wall surface in a state of being bent in a dogleg shape. And if the boundary part of the 1st storage chamber 15 and the 2nd storage chamber 16 of the bottom wall of the casing 5 passes, the cleaning member 1 will return to the original state, and will pass the detection surface 13a.

  Further, when passing through the boundary portion between the first storage chamber 15 and the second storage chamber 16 on the bottom wall, the cleaning member 1 suddenly recovers elastically. Thus, by suddenly recovering elasticity, the developer staying in the vicinity of the detection surface 13a can be blown off, and the detection accuracy of the toner amount detection sensor 13 can be stabilized.

  Thus, the rotating shaft 7a of the first stirring screw 7 is substantially perpendicular to the side wall 5a in the casing 5, and the cleaning member 1 is more than the rotating shaft 7a of the first stirring screw 7 by the locking portion 1b. The first agitating screw 7 is fixed to the detection surface 13a side and can be elastically deformed in a direction parallel to the detection surface 13a by the first winding spring portion 1a, and by the first cleaning portion 1c connected to the first winding spring portion 1a. In contact with the detection surface 13a. And the cleaning member 1 is formed so that the length from the axial center of the rotating shaft 7a to the tip of the first cleaning portion 1c is longer than the length from the axial center of the rotating shaft 7a to the inner wall surface of the casing 5. Has been.

  Therefore, since the length from the shaft center of the rotating shaft 7a to the tip of the first cleaning portion 1c is longer than the length from the shaft center of the rotating shaft 7a to the inner wall surface of the casing 5, the rotation of the first stirring screw 7 is performed. Accordingly, the first cleaning unit 1 c comes into sliding contact with the inner wall surface of the casing 5. At this time, the force applied to the first cleaning part 1c is absorbed by the elastic deformation of the first winding spring part 1a, and the excessive load on the first cleaning part 1c is reduced, so that toner aggregates are generated. Therefore, the detection accuracy of the toner amount detection sensor 13 can be stabilized and the image quality can be stabilized without increasing the size of the apparatus.

  Further, even when the surface treatment agent is deeply embedded in the toner and the fluidity is deteriorated, the detection failure of the sensor does not occur and the life of the toner can be extended. Furthermore, even if the toner fluidity deteriorates, the detection failure of the toner amount detection sensor 13 can be improved, so that the detection performance of the toner amount detection sensor 13 in a special environment of high temperature and high humidity is improved. Can do.

  Furthermore, if there is an uncleaned area on the detection surface 13a of the toner amount detection sensor 13, a detection failure may occur. For this reason, a great deal of time is required for performance confirmation and improvement during development. However, in the present invention, since the detection surface 13a of the toner amount detection sensor 13 can be reliably cleaned, the time required for performance check can be reduced, and the development efficiency can be improved. In addition, since the toner amount can be detected stably even if the toner has deteriorated fluidity, the degree of freedom in designing the toner is widened, the image quality is improved as the toner particle size is reduced, and the toner is manufactured. This can contribute to cost reduction.

  Further, the first winding spring portion 1a is inserted into a support member 7c provided on the detection surface 13a side of the rotation shaft 7a of the first stirring screw 7, and one end of the first winding spring portion 1a is bent and formed. The stop 1b is locked to the rotating shaft 7a. The 1st cleaning part 1c is comprised by the other end of the 1st winding spring part 1a extended in the direction substantially perpendicular | vertical to the rotating shaft 7a. Accordingly, since the force applied to the first cleaning portion 1c is absorbed by the first winding spring portion 1a, the first winding spring portion 1a can be prevented from being damaged or deformed, and the life of the apparatus can be extended. it can.

  In the conventional developing device, the first winding spring portion 1a is provided on the rotation shaft 7a of the first stirring screw 7. However, in the present invention, the first winding spring portion 1a is the rotation shaft of the first stirring screw 7. It is provided closer to the detection surface 13a than 7a. Therefore, it is possible to reduce a load applied to the first winding spring portion 1a that is elastically deformed when the first cleaning portion 1c is slidably contacted with the inner wall of the casing 5, and prevents the first winding spring portion 1a from being damaged or deformed. Therefore, the life of the apparatus can be extended.

  Further, the first cleaning unit 1c is configured by the other end of the first coiled spring unit 1a extending in a direction substantially perpendicular to the rotation shaft 7a, and the second cleaning unit 18 detects the toner amount at the tip of the first cleaning unit 1c. The sensor 13 is formed to be bent substantially perpendicularly to the detection surface 13a, and further, the tip thereof is bent substantially perpendicularly to the first cleaning part 1c in a direction having a predetermined angle. The third cleaning part 19 is formed by the second cleaning part 18. The tip of the toner is bent substantially perpendicularly toward the detection surface 13 a of the toner amount detection sensor 13.

  Accordingly, the first cleaning part 1c, the bent part 17, the second cleaning part 18 and the third cleaning part 19 can more effectively disperse the developer staying in the vicinity of the detection surface 13a, thereby detecting the toner amount. The detection accuracy of the sensor 13 can be stabilized.

  In this embodiment, a magnetic one-component developer is used. However, the present invention is not particularly limited to this. For example, a non-magnetic one-component developer composed of only a non-magnetic toner may be used. Further, a two-component developer composed of a toner and a carrier, a developer using a small particle carrier having an average particle diameter of 70 μm or less, preferably 60 to 70 μm, and a developer using a resin carrier may be used. Good. When these developers are used, fluidity deteriorates due to deterioration. Therefore, by applying the developing device according to the present invention, the same effect as the present invention can be obtained.

  In addition, although the 1st stirring screw 7 and the 2nd stirring screw 8 in this embodiment are the spiral structures which provided the spiral blades 7b and 8b around the rotating shafts 7a and 8a, respectively, this invention is specifically limited to this. Instead, a paddle structure, a structure using a sheet blade, a structure using a spiral and a paddle, a structure in which a rod-shaped member is bent, or the like may be used.

  Further, in this embodiment, the cleaning member 1 is provided on the first stirring screw 7 separated from the developing roller 11, but the present invention is not particularly limited to this, and the second stirring screw 8 close to the developing roller 11 is cleaned. The member 1 may be provided. In this case, even with a small amount of toner, a strong pressure is applied to the detection surface 13 a of the toner amount detection sensor 13. Therefore, in order to prevent a detection failure, it is necessary to provide the toner amount detection sensor 13 at a position slightly away from the rotation shaft 8a of the second stirring screw 8. Therefore, by applying the present invention also in such a case, the same effect as the present invention can be obtained.

FIG. 3 is a diagram illustrating a configuration of a printer using the developing device according to the present invention. 1 is a perspective view illustrating a schematic configuration of a developing device according to the present invention. FIG. 3 is a side view illustrating a schematic configuration of the developing device illustrated in FIG. 2. FIG. 3 is a front view of the developing device shown in FIG. 2 as viewed from above. It is the figure which expanded the edge part of the 1st stirring screw shown in FIG. It is the sectional view on the AA line of FIG. It is a figure which shows the cross section of the axial center direction of the edge part of the 1st stirring screw shown in FIG. It is the figure which looked at the cleaning member from the arrow C direction of FIG. It is the figure which looked at the cleaning member from the arrow D direction of FIG. It is a figure for demonstrating operation | movement of the cleaning member.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cleaning member 1a 1st winding spring part 1b Locking part 1c 1st cleaning part 5 Casing 6 Cover 7 1st stirring screw 7a, 8a Rotating shaft 7b, 8b Spiral blade 7c Support member 8 2nd stirring screw 9 Partition plate 11 Development Roller 12 Regulating blade 13 Toner amount detection sensor 13a Detection surface 15 First storage chamber 16 Second storage chamber 17 Bending portion 18 Second cleaning portion 19 Third cleaning portion 101 Developing device

Claims (7)

A housing for storing the developer, a detecting means provided on a side surface in the housing for detecting the amount of the developer, a stirring member for stirring the developer in the housing, and the detecting means as the stirring member rotates. A developing device comprising a cleaning member for cleaning the detection surface of
The rotating shaft of the stirring member is substantially perpendicular to the side surface in the housing,
The cleaning member is fixed to the detection surface side of the rotating shaft of the stirring member and is elastically deformable in a direction parallel to the detection surface, and is connected to the elastic portion with the rotation of the stirring member. A cleaning unit that is in sliding contact with the detection surface,
The developing device according to claim 1, wherein a length from an axis of the rotating shaft to a tip portion of the cleaning unit is longer than a length from an axis of the rotating shaft to an inner wall surface of the casing. A housing for storing the two-component developer, a detecting means provided on a side surface in the housing for detecting a mixing ratio of the toner and the carrier of the two-component developer, and a stirring member for stirring the developer in the housing And a developing device comprising a cleaning member for cleaning the detection surface of the detection means as the stirring member rotates,
The rotating shaft of the stirring member is substantially perpendicular to the side surface in the housing,
The cleaning member is fixed to the detection surface side of the rotating shaft of the stirring member and is elastically deformable in a direction parallel to the detection surface, and is connected to the elastic portion with the rotation of the stirring member. A cleaning unit that is in sliding contact with the detection surface,
The developing device according to claim 1, wherein a length from an axis of the rotating shaft to a tip portion of the cleaning unit is longer than a length from an axis of the rotating shaft to an inner wall surface of the casing. The stirring member includes a support member provided closer to the detection surface than the rotation shaft,
The elastic portion includes a first winding spring portion that is inserted into the support member, a locking portion that is formed by bending one end of the first winding spring portion, and is locked to the rotating shaft or the support member. Including
3. The developing device according to claim 1, wherein the cleaning unit is configured by the other end of the first coil spring portion extending in a direction substantially perpendicular to the rotation shaft.   The cleaning unit includes a first cleaning unit configured by the other end of the first coil spring portion extending in a direction substantially perpendicular to the rotation shaft, and a detection surface of the detection unit at the tip of the first cleaning unit. A second cleaning part that is bent substantially perpendicularly with respect to the first cleaning part and bent substantially perpendicularly to the first cleaning part in a direction having a predetermined angle, and the tip of the second cleaning part is the detection surface. The developing device according to claim 3, further comprising a third cleaning portion that is formed by being bent substantially perpendicularly to the direction.   The distance from the axis of the rotation shaft to the inner wall surface of the housing is the radius of the rotation axis and the detection surface farthest from the edge of the detection surface of the detection means closest to the axis. 5. The developing device according to claim 1, wherein the developing device is shorter than a distance obtained by adding a length to an edge portion of the ink and a thickness between the rotation shaft and the detection unit. Further comprising support means for supporting the rotating shaft of the stirring member,
The said support means is provided in the side surface of the said housing | casing same as the said detection surface, and has protruded inside or the outer side with respect to the said side surface. Development device.   The developing device according to claim 1, wherein the detection unit is a piezoelectric sensor.

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