JP2010002854A - Developing apparatus and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent toner from splashing to the outside of a developing apparatus. <P>SOLUTION: The developing apparatus 100 is equipped with: a development roll 113, which conveys the developer containing toner T and magnetic carrier particles and supplies the toner T to a rotating photoreceptor drum 23, thereby developing an electrostatic latent image formed on the photoreceptor drum 23; a toner recovery roll 140 which recovers splashed toner T to a side nearer the downstream side than the developing roll 113 in the rotating direction (arrow B direction) of the development roll 113; and a shield 150 which bounces back the splashed toner T toward the toner recovery roll 140 , on a side farther down side to the downstream of the toner recovery roll 140, in the rotating direction (direction of arrow A) of the photoreceptor drum 23. In the developing apparatus 100, the splashed toner T is bounced back directly or with the shield 150, and is recovered by the toner recovery roll 140. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a developing device and an image forming apparatus.

  As conventional image forming apparatuses, there are image forming apparatuses described in Patent Documents 1 to 5, for example. The image forming apparatus described in Patent Document 1 is a conductive material that is close to the developer holding body and also close to and faces the electrostatic latent image holding body on the downstream side of the developing region A in the moving direction of the surface of the developer holding body. Equipped with sex rolls. The conductive roll rotates so that both opposing surfaces move in the same direction at a position facing the developer holding member during development, and a bias voltage is applied between the two. As a result, the toner scattered from the developing area A is adsorbed by the conductive roll or collected by the air flow into the developing device.

  The image forming apparatus described in Patent Document 2 vibrates by applying an alternating current to a developing device having a magnet roll and a toner supply / recovery roll opposed to the lower outer periphery of the magnet roll at a predetermined interval. The upper end of the thin plate is positioned in the vicinity of the development area, a non-conductive member is provided on the thin plate, and the thin plate is brought into contact with the toner supply / collection roll via the non-conductive member, and an alternating current is applied to the thin plate. And bias means. In this image forming apparatus, falling toner captured by a thin plate is collected on a toner supply / collection roll.

  In the image forming apparatus described in Patent Document 3, a collection roll made of a conductive material is accommodated in a collection casing of the collection apparatus, and the collection roll rotates clockwise. The collection roll is disposed with a gap on the circumferential surface of the photosensitive drum. The edge of the scraper is in contact with the collecting roll. A voltage application device for applying a voltage to the collection roll is provided.

  An image forming apparatus described in Patent Document 4 includes a photosensitive drum on which an electrostatic latent image is formed, a charger for charging the photosensitive drum in advance, a developing roll for supplying toner to the photosensitive drum, In an image forming apparatus including an apparatus main body for storing each part, a conductive member to which a predetermined voltage is applied is provided, and a blade-like rotating member is provided between the conductive member and the charger. Further, the rotation direction of the blade-like rotating member is set so that the side of the blade-like rotating member close to the floating toner generation region approaches the conductive member. Further, the blade-like rotating member and the conductive member are arranged close to each other. Further, a voltage having a polarity opposite to the charged polarity of the floating toner floating in the apparatus main body is applied to the conductive member.

The image forming apparatus described in Patent Document 5 uses a non-contact developing device for reversal development in a color image forming apparatus in which a toner image is superimposed on a photosensitive drum by repeating charging, image exposure, and reversal development, After the development, the toner recovery device includes a recovery roll to which a voltage having the same polarity as the charging potential of the photosensitive drum and a high absolute value is applied before the next charging.
JP 05-066663 A JP 05-088537 A JP 05-158386 A Japanese Patent Laid-Open No. 08-194377 Japanese Patent Application Laid-Open No. 09-230893

  The present invention has been made on the basis of the technical background as described above, and an object of the present invention is to provide a technique for preventing the toner from scattering outside the developing device.

  According to the first aspect of the present invention, an electrostatic latent image formed on the image carrier is obtained by conveying a developer containing toner and magnetic carrier particles and supplying the toner to a rotating image carrier. A developing means for developing the toner, a collecting means for collecting the scattered toner downstream of the developing means in the rotational direction of the image carrier, and a downstream of the collecting means in the rotational direction of the image carrier. A developing device comprising: rebounding means for rebounding the scattered toner toward the collecting means.

  According to a second aspect of the present invention, in the first aspect of the present invention, a voltage having a polarity opposite to the charge of the toner is applied to the recovery means, and a voltage having the same polarity as the charge of the toner is applied to the rebound means. Is applied.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, the image holding member has a first surface in the direction of gravity on the downstream side of the rebound means in the rotation direction of the image carrier and above the rebound means. The developing means, the collecting means and the rebound means are provided, and the rebound means is provided on the image holding member side of the first surface.

  A fourth aspect of the present invention is an image forming apparatus comprising the developing device according to any one of the first to third aspects.

  According to the first aspect of the present invention, it is possible to prevent the toner from scattering outside the developing device as compared with the case where the present invention is not applied.

  According to the second aspect of the present invention, it is possible to prevent the toner from scattering outside the developing device as compared with the case where the present invention is not applied.

  According to the third aspect of the present invention, it is possible to prevent excessive toner from being supplied to the image carrier as compared with the case where the present invention is not applied.

  According to the fourth aspect of the present invention, it is possible to prevent the recording medium on which an image is formed, devices around the developing device, and the like from being contaminated with toner, as compared with the case where the present invention is not applied.

(Color printer configuration)
Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic view showing a color printer according to an embodiment of the present invention.

  As shown in FIG. 1, the tandem color printer (image forming apparatus) 1 is roughly divided into a feeding unit 3 that feeds continuous paper 2 and a first (Y) color image. An image forming unit 4; a second image forming unit 5 that forms a magenta (M) color image; a third image forming unit 6 that forms a cyan (C) color image; and a black (K) color A toner is formed on the fourth image forming unit 7 that forms an image and the continuous paper 2 on which toner images of each color of yellow (Y), magenta (M), cyan (C), and black (K) are transferred in multiple. A fixing unit 8 that fixes an image, a tension adjustment unit 9 that adjusts the tension of the continuous paper 2, a main print control unit 10 that includes controls, and sub printing corresponding to the image forming units 4 to 7 for each color It is comprised from the control parts 11-14.

  The feeding unit 3 conveys the continuous paper 2 fed from a paper feeding unit (not shown) by three paper feeding rolls 15 while being sandwiched between a pair of rolls via a curved conveyance path 16. A roll 17 and a follower roll 18 are provided, and are guided by a plurality of guide rolls 19 to 22 that guide the continuous paper 3. Here, the continuous paper 2 is a series of continuous belt-like paper, and is a recording medium that is separated by creases (perforations) for each page.

  The first to fourth image forming units 4 to 7 of yellow (Y), magenta (M), cyan (C), and black (K) differ only in the color of the image to be formed, and the others are the same. Here, the first image forming unit 4 that forms a yellow (Y) toner image will be described as an example.

  The first image forming unit 4 is provided with a photosensitive drum (image holding member) 23 that is rotatable. Two primary chargers 24 and 25 for charging the surface of the photosensitive drum 23 to a predetermined potential are arranged side by side on the lower left side of the photosensitive drum 23. Below the photosensitive drum 23, an optical unit 26 is provided as image exposure means for performing image exposure on the surface of the photosensitive drum 23 charged to a predetermined potential by the primary chargers 24 and 25 in accordance with image information. An image is exposed on the surface of the photosensitive drum 23 by the optical unit 26, and an electrostatic latent image corresponding to the image information is formed.

  The electrostatic latent image formed on the surface of the photosensitive drum 23 is developed by the developing device 100 provided on the right side of the photosensitive drum 23 to form a toner image made of powder toner. Details of the developing device 100 will be described later.

  Further, a transfer roll 29 is provided above the photosensitive drum 23 as a transfer unit for transferring the toner image formed on the photosensitive drum 23 to the continuous paper 2. The formed toner image is charged by the transfer roll 29 and transferred onto the continuous paper 2.

  The continuous paper 2 onto which the yellow toner image has been transferred from the yellow photosensitive drum 23 by the transfer roll 29 is sequentially conveyed to the downstream image forming units 5 to 7, and magenta (M), cyan ( C) Toner images of black (K) are sequentially transferred in multiple. Thereafter, the continuous paper 2 is conveyed to the fixing unit 8 by the conveyance rolls 33, 34, and 35, and an unfixed toner image is fixed on the continuous paper 2 by the fixing device 36 provided in the fixing unit 8. At that time, the continuous paper 2 is folded on the paper discharge unit (not shown) by the transport roll 41 via the rolls 38, 39, and 40 with the tension adjusted by the tension adjustment mechanism 37 of the tension adjustment unit 9. It is discharged in the state.

(Color printer operation)
Next, the operation of the color printer 1 will be described. The color printer 1 transfers the C, M, Y, and K color toner images formed on the surface of each photosensitive drum 23 onto the continuous paper 2 being conveyed. Then, the color printer 1 sends the continuous paper 2 to the fixing unit 8, fixes the transferred toner image on the continuous paper 2, and discharges the continuous paper 2 to the paper discharge unit.

(Configuration of developing device)
Next, the configuration of the developing device 100 will be described with reference to the drawings. FIG. 2 is a sectional view showing the developing device. FIG. 3 is a schematic view showing the developing device. FIG. 4 is a diagram illustrating the operation of the toner.

  As shown in FIG. 2, the developing device 100 includes a housing (housing unit) 101, developing rolls 111, 112, and 113 provided in the vertical direction along the rotation direction (arrow A direction) of the photosensitive drum 23, Among the developing rolls 111 to 113, a transport mechanism 120 is provided below the developing roll 111 that is located at the lowest position in the direction of gravity. A developer regulating blade 130 is provided so as to face the developing roll (developing unit) 113 positioned at the uppermost position in the direction of gravity.

  Further, a toner collecting roll (collecting means) 140 is provided on the downstream side of the developing roll 113 in the rotation direction of the photosensitive drum 23 (direction of arrow A). Further, a shield (bounce means) 150 is provided on the downstream side of the toner collecting roll 140 in the rotation direction of the photosensitive drum 23 (direction of arrow A). A recovery scraper 160 is provided so as to face the toner recovery roll 140.

  The housing 101 is a box having an open surface on the side facing the photosensitive drum 23. The casing 101 has an upper surface (first surface) on the downstream side of the shield 150 in the rotational direction (arrow A direction) of the photosensitive drum 23 and above the shield 150 in the direction of gravity. Inside the casing 101, developing rolls 111 to 113, a transport mechanism 120, a developer regulating blade 130, a toner collecting roll 140, a shield 150, and a collecting scraper 160 are housed.

  The conveyance mechanism 120 includes a conveyance screw 121 and a conveyance screw 122, a pre-stirring paddle 123 that preliminarily agitates the toner T supplied to the developing device 100 from the outside and supplies the toner T to the conveyance screw 122, and a development conveyed by the conveyance screw 121. And a conveyor roll 124 for adhering the agent to the developing roll 111. The transport mechanism 120 transports the developer composed of the toner T and magnetic carrier particles toward the developing roll 111, and supplies the developer to the developing rolls 111 to 113. Here, the toner T is positively charged by friction caused by stirring and is electrostatically adsorbed to the magnetic carrier particles.

  As shown in FIG. 2, each of the developing rolls 111 to 113 includes a fixed magnetic pole 110a and a rotating sleeve 110b that covers the fixed magnetic pole 110a. The conveyor roll 124 also includes a fixed magnetic pole 124a and a rotating sleeve 124b that covers the fixed magnetic pole 124a.

  The rotating sleeves 110b of the developing rolls 111 to 113 rotate in the same direction (arrow B direction) as that of the photosensitive drum 23 (arrow A direction). Accordingly, in each of the developing rollers 111 to 113, the developing surface of the rotating sleeve 110b facing the photosensitive drum 23 moves in the direction opposite to the surface of the photosensitive drum 23.

  As shown in FIG. 3, a predetermined voltage is applied to the developing rolls 111 to 113 by a developing bias power supply 110P. In the present embodiment, the surface potential of the photosensitive drum 23 is set to + 600V. The developing rolls 111 to 113 are toner T among the developers conveyed by the developing roll 23 due to an electric field formed between the developing rolls 111 to 113 and the photosensitive drum 23 by a voltage applied to the developing rolls 111 to 113. Only the toner is moved onto the photosensitive drum 23 for development.

  The developer regulating blade 130 is provided so as to face the developing roll 113. The developer regulating blade 130 is a plate-like member having a trapezoidal cross section and extending over the entire width of the developing roll 113. The developer regulating blade 130 is provided with shaft portions (not shown) at both ends, and is supported by the housing 101 by the shaft portions. The developer regulating blade 130 regulates the thickness of the developer layer by dropping the developer conveyed by the developing roll 113 from the developing roll 113 onto the scraping and conveying mechanism 120.

  As shown in FIG. 4, the range from the developer regulating blade 130 to the photosensitive drum 23 in the rotation direction of the developing roll 113 (the direction of arrow B) is the toner due to the centrifugal force generated by the rotation of the rotating sleeve 110 b of the developing roll 113. This is where T is scattered. Therefore, in the range from the developer regulating blade 130 to the photosensitive drum 23, the toner T is more scattered as the rotational speed of the rotary sleeve 110b increases. The scattered toner T is scattered along the air flow generated by the rotation of the photosensitive drum 23. That is, the scattered toner T is further scattered toward the downstream side in the rotation direction (arrow A direction) of the photosensitive drum 23.

  The toner collecting roll 140 is provided on the downstream side of the developing roll 113 in the rotation direction (arrow A direction) of the photosensitive drum 23. The toner collecting roll 140 is provided in a range from the developer regulating blade 130 to the photosensitive drum 23 in the rotation direction (arrow B direction) of the developing roll 113. Further, the toner collecting roll 140 is provided to face the photosensitive drum 23 and be separated from the photosensitive drum 23 by a predetermined distance. In the present embodiment, the distance L1 between the photosensitive drum 23 and the toner collection roll 140 is about 0.5 mm.

  As shown in FIG. 3, a predetermined voltage is applied to the toner collection roll 140 by an adsorption power source 140P. The voltage applied to the recovery means is set to about 0 V or less to about the distance (mm) × (−1000) V between the image carrier and the recovery means. By setting the voltage applied to the recovery means in such a range, the influence of the recovery means on the image carrier can be suppressed. In this embodiment, the voltage applied to the toner collection roll 140 is set to about 0 V or less to about the distance L1 (mm) × (−1000) V between the photosensitive drum 23 and the toner collection roll 140. Accordingly, since the voltage is about 0 V or more to about 0.5 × (−1000) V or more, a voltage of about −500 V is applied to the toner collecting roll 140. That is, a voltage having a polarity opposite to the charge of the toner T is applied to the toner collecting roll 140. As shown in FIG. 4, the toner collection roll 140 is applied with a voltage having a polarity opposite to the charge of the toner T, and thus collects the scattered toner T by electrostatic adsorption.

  The toner collecting roll 140 may include a fixed magnetic pole and a rotating sleeve placed on the fixed magnetic pole, and may also have a function of collecting magnetic carrier particles attached to the photosensitive drum 23.

  The shield 150 is provided on the downstream side of the toner collecting roll 140 in the rotation direction of the photosensitive drum 23 (direction of arrow A). The shield 150 is provided on the upper surface 102 of the casing 101 on the photosensitive drum 23 side. Further, the shield 150 is provided at a predetermined distance from the photosensitive drum 23. In the present embodiment, the distance L2 between the photosensitive drum 23 and the shield 150 is about 1.5 mm.

  As shown in FIG. 3, a predetermined voltage is applied to the shield 150 by a repulsive power source 150P. The voltage applied to the rebound means is set to be not less than the surface potential of the image holding body and not more than the distance (mm) × (+1000) V between the image holding body and the rebound means. In the present embodiment, the voltage applied to the shield 150 is set to be not less than the surface potential of the photosensitive drum 23 to not more than the distance L2 (mm) × (+1000) V between the photosensitive drum 23 and the shield 150. Therefore, since the voltage is about +600 V to 1.5 × (+1000) V or less, a voltage of about +1000 V is applied to the toner collection roll 140. That is, a voltage having the same polarity as the charge of the toner T is applied to the shield 150.

  The shield 150 is provided at a predetermined distance from the toner collection roll 140. The distance (mm) between the recovery means and the rebound means is set to about {(voltage applied to the recovery means (V)) − (voltage applied to the rebound means (V))} ÷ 1000 or more. That is, the distance (mm) is set as 1000 (V) = 1.0 (mm). In this embodiment, the distance (mm) between the toner collection roll 140 and the shield 150 is about {(voltage (V) applied to the toner collection roll 140) − (voltage (V) applied to the shield 150)} ÷ 1000. Set to above. Therefore, since {(+ 1000V) − (− 500V)} ÷ 1000 or more, the distance L3 between the photosensitive drum 23 and the shield 150 is set to about 1.5 mm or more.

  Since a voltage having the same polarity as the electric charge of the toner T is applied to the shield 150, the scattered toner T rebounds toward the toner collecting roll 140. Specifically, the shield 150 rebounds toward the toner collection roll 140 by electrostatically repelling the toner T that has not been collected by the toner collection roll 140 and scattered toward the downstream side of the photosensitive drum 23, The toner is collected by the toner collecting roller 140. Therefore, the scattered toner T is prevented from scattering outside the casing 101. Further, compared to the case where the toner T scattered by a suction device including an air duct is sucked, the toner T is held inside the housing 101, and the consumption of the toner T is prevented from increasing.

  Further, since the shield 150 is provided on the upper surface 102 of the housing 101, the scattered toner T adheres to the upper surface 102 of the housing 101 as compared to the case where the shield 150 is not provided on the upper surface 102 of the housing 101. Prevent accumulation. Therefore, the accumulated toner T is prevented from dropping on the developing roll 113. As a result, the excessive toner T is prevented from being supplied to the photosensitive drum 23, thereby preventing the image formed on the continuous paper 2 from being defective.

  Note that the present invention is not limited to the embodiment in which the shield 150 to which a voltage having the same polarity as the charge of the toner T is applied, but may be an embodiment in which a rebound means for repelling the toner T scattered by the air is provided.

  The recovery scraper 160 is provided to face the toner recovery roll 140. The recovery scraper 160 is a plate-like member that extends over the entire width of the toner recovery roll 140. The collection scraper 160 has a length that exceeds the developer regulating blade 130 from the toner collecting roll 140 in a direction transverse to the gravity direction, and is provided above the developer regulating blade 130 in the gravity direction. . The recovery scraper 160 is inclined downward from the toner recovery roll 140 toward the developer regulating blade 130. The recovery scraper 160 is provided with shaft portions (not shown) at both ends, and is supported by the housing 101 by the shaft portions. The collection scraper 160 scrapes off the toner T collected and conveyed by the toner collection roll 140, drops the toner T by gravity, and returns it to the conveyance mechanism 120. Therefore, the scattered toner T can be held inside the casing 101.

(Developer operation)
Next, the operation of the developing device 100 will be described with reference to the drawings.

The toner T supplied from outside is stirred by the pre-stir paddle 123 and supplied to the conveying screw 122. The developer supplied to the conveying screw 122 is conveyed to the conveyor roll 124 by the conveying screw 121. Next, the rotating sleeve 124 b of the conveyor roll 124 rotates in a direction opposite to the direction of rotation of the developing roll 111 (arrow B direction), so that the developer adheres to the rotating sleeve 110 b of the developing roll 111.

  Since the developing rolls 111 to 113 are all rotated in the direction of arrow B, the surface of the rotating sleeve 110b moves from the lower side to the upper side on the back side. Therefore, the developer attached to the rotating sleeve 110 b of the developing roll 111 also moves from below to above and is transferred to the developing roll 112. The developer transferred to the developing roll 112 also moves upward from below and is transferred to the developing roll 113.

  The developer transferred to the developing roll 113 moves along the developing roll 113 from the back side toward the developing side, but the predetermined developer is scraped off by the developer regulating blade 130 on the way, and the transport mechanism Drop toward 120. The developer that has passed through the developer regulating blade 130 moves to the development surface. At this time, the scattered toner T is bounced back directly or onto the shield 150 and is collected by the toner collecting roll 140. The recovered toner T is scraped off by the recovery scraper 160 and returned to the conveying device 120.

  On the developing surface side, the developer is transferred from the developing roll 113 to the developing roll 112 and from the developing roll 112 to the developing roll 111 while moving from above to below. Accordingly, the moving direction of the developer on the developing surface is opposite to the rotation direction of the photosensitive drum 23 (the direction of the arrow A), so the electrostatic latent image formed on the surface of the photosensitive drum 23 is the toner in the developer. Developed by T. The developed developer falls from the developing roll 111 to the conveying screw 121.

(Advantages of this embodiment)
The superiority of this embodiment will be described with reference to the drawings and tables. FIG. 5 is a diagram showing the relationship between the applied voltage and the surface reflection density of the toner recovery roll. FIG. 6 is a diagram illustrating the surface of the recording medium when a positive voltage is applied. FIG. 7 is a diagram illustrating the surface of the recording medium when a negative voltage is applied. Table 01 is a table showing the relationship between the applied voltage and the surface reflection density of the toner recovery roll. The black dots shown in FIGS. 6 and 7 are fog.

  The surface reflection density of the toner collecting roll 140 will be described with reference to FIGS. The horizontal axis in FIG. 5 is the applied voltage (V) applied to the toner collecting roll 140. The vertical axis in FIG. 5 represents the surface reflection density of the toner collection roll 140.

  Here, the surface reflection density will be described. The surface reflection density is a scale when the amount of light reflected from a sample is compared with the amount of light reflected from a basic material or a reference material. The surface reflection density increases as the amount of toner T adhering to the surface of the toner collection roll 140 increases, because the amount of light reflected from the sample differs from the amount of light reflected from the basic material. Further, fog will be described. The term “fogging” refers to a stain on the recording medium in which toner that is excessively attached to the recording medium is fixed to the recording medium and becomes dirty except for a portion that forms an image on the recording medium such as continuous paper or paper.

  As shown in FIG. 5 and Table 01, when the applied voltage is 500 V, the surface reflection density of the toner recovery roll 140 is 0.45. When the applied voltage is 100 V, the surface reflection density of the toner collecting roll 140 is 1.14, which is higher than that when the applied voltage is 500 V. That is, when the applied voltage is 100V, the amount of the scattered toner T collected increases compared to the applied voltage of 500V. Further, when the applied voltage is −500 V, the surface reflection density of the toner collecting roll 140 is 1.4, which is higher than that when the applied voltage is 100 V. That is, when the applied voltage is -500 V, the amount of the scattered toner T is further increased as compared with the applied voltage of 100 V.

  For this reason, when a negative voltage is applied, the amount of scattered toner T adhering to the toner collecting roll 140 increases compared to when a positive voltage is applied, and thus the adhering to the photosensitive drum 23 is scattered. The amount of toner T decreases. As a result, the number of fog when a negative voltage as shown in FIG. 7 is applied is smaller than the number of fog when a positive voltage as shown in FIG. 6 is applied.

  Thus, when a negative voltage is applied, the number of fogs is reduced as compared with a case where a positive voltage is applied. Therefore, when a negative voltage is applied, the toner T is prevented from scattering from the inside of the developing device 100 to the outside of the developing device 100 as compared with the case where a positive voltage is applied. A good quality image is obtained. As a result, from the viewpoint of the quality of the image formed on the recording medium, it can be said that there is an advantage when a negative voltage is applied.

  The present invention can be used for an image forming apparatus having a printer function, a FAX function, a copying function, or these functions, and a developing device.

1 is a schematic diagram illustrating a color printer according to an embodiment of the present invention. It is sectional drawing which shows a developing device. It is the schematic which shows a developing device. FIG. 6 is a diagram illustrating an operation of toner. It is a figure which shows the relationship between an applied voltage and the surface reflection density of a toner collection | recovery roll. It is a figure which shows the surface of a recording medium at the time of applying a positive voltage. It is a figure which shows the surface of a recording medium at the time of applying a negative voltage.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Color printer, 23 ... Photosensitive drum, 100 ... Developing apparatus, 101 ... Housing, 102 ... Upper surface, 113 ... Developing roll, 140 ... Toner collection roll, 150 ... Shield, T ... Toner.

Claims (4)

Developing means for developing an electrostatic latent image formed on the image carrier by conveying a developer containing toner and magnetic carrier particles and supplying the toner to a rotating image carrier;
A collecting means for collecting scattered toner downstream of the developing means in the rotation direction of the image carrier;
A developing device, comprising: a rebound unit that repels the scattered toner toward the collection unit on a downstream side of the collection unit in a rotation direction of the image carrier. A voltage having a polarity opposite to the charge of the toner is applied to the recovery means,
The developing device according to claim 1, wherein a voltage having the same polarity as the charge of the toner is applied to the rebound unit. A first unit having a first surface on the downstream side of the repelling unit in the rotation direction of the image holding body and above the rebounding unit in the direction of gravity;
The developing device according to claim 1, wherein the bounce unit is provided on the image holding member side of the first surface. An image forming apparatus comprising the developing device according to claim 1.

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