JP2018112651A - Developing device and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a developing device that can suppress a reduction in contact pressure of layer thickness regulation means in a longitudinal direction of a developer carrier with a simple configuration.SOLUTION: A developing device comprises: a developing sleeve 5a that carries developer in a container frame body 37; a toner regulation member 35 that is fixed to the container frame body 37 in a predetermined direction at fixing positions at both sides in a longitudinal direction, and regulates a layer thickness of the developer carried on the developing sleeve 5a; and a top cover 300 serving as pressing means that presses the toner regulation member 35, that has an area projecting in a direction parallel to a predetermined direction beyond positions to press the fixing positions between the positions to fix the toner regulation member 35 to the container frame body 37.SELECTED DRAWING: Figure 8

Description

  The present invention relates to a developing device provided in an image forming apparatus such as a copying machine, a printer, or a facsimile machine.

  In an electrophotographic image forming apparatus, toner (developer) stored in a developing container is supplied by a developing sleeve (developer carrier) to an electrostatic latent image formed on the surface of a photosensitive drum. As a result, the toner image (developer image) is developed on the photosensitive drum to form a visible image.

  The toner carried on the developing sleeve is regulated in layer thickness by a plate-like toner regulating member (layer thickness regulating member). The toner regulating member is supported by the presser sheet metal. The vicinity of the free end side of the toner regulating member is in contact with the surface of the developing sleeve in a surface contact state. The contact method of the toner regulating member with respect to the developing sleeve is a so-called counter (reverse) direction in which the front end side is located upstream of the developing sleeve rotation method with respect to the contact portion.

  The developing sleeve uses urethane rubber, silicon rubber, or the like. As the conductive layer, a metal thin plate of SUS (stainless steel) or phosphor bronze having spring elasticity is used. In addition, there is one in which silicon rubber is integrally formed on a steel plate.

  During the developing operation, the toner in the developing container is transported to the vicinity of the developing sleeve as the stirring member rotates, and the amount of toner carried on the surface of the developing sleeve at the contact portion between the developing sleeve and the toner regulating member is reduced. The contact pressure is adjusted to be constant. Then, it is frictionally charged by being rubbed against the developing sleeve. Here, after receiving a proper tribo (friction charge amount) and forming a thin layer on the developing sleeve, it flies to the photosensitive drum.

  If the contact pressure becomes too large, the amount of toner carried on the surface of the developing sleeve decreases. Then, toner deterioration is accelerated and toner fusion occurs on the surface of the developing sleeve. As a result, sufficient toner does not fly to the photosensitive drum and the image quality deteriorates (white streaks, density reduction, density unevenness). On the other hand, if the contact pressure is low, the amount of toner carried on the surface of the developing sleeve becomes too large. For this reason, frictional charging due to rubbing becomes insufficient. For this reason, a reduction in image quality occurs. In order to prevent such a problem from occurring, it is required that the contact pressure be within a certain range.

  Furthermore, even if the contact pressure is different between the end portion in the longitudinal direction and the central portion (longitudinal direction), the same problem may occur, and the contact pressure of the toner regulating member that contacts the surface of the developing sleeve is The entire surface needs to be uniform. The toner regulating member is fixed to the container frame of the developing container by screwing the end portion of the sheet metal in the longitudinal direction. The contact pressure is adjusted by interposing a spacer at the screw tightening position. The end of the toner regulating member in the longitudinal direction is fixed to the container frame of the developing container. For this reason, when the toner regulating member comes into contact with the developing sleeve, even if the toner regulating member is pushed by the developing sleeve, the force is difficult to escape. For this reason, the contact pressure of the toner regulating member that contacts the developing sleeve is easily held.

  On the other hand, since the central portion of the toner regulating member is not fastened with screws, when the toner regulating member comes into contact with the developing sleeve, the toner regulating member is pushed by the developing sleeve and the force tends to escape to the opposite surface. As a result, the contact pressure at the center portion is lower than the end portion in the longitudinal direction of the toner regulating member.

  In Patent Document 1, a large dedicated device is used to make the contact pressure when the toner regulating member contacts the developing sleeve uniform. This special device is used to eliminate variations in the contact pressure of the toner regulating member, which is caused by the mounting accuracy of the toner regulating member and component tolerance when the toner regulating member is fixed to the developing container with screws.

JP 2001-100517 A

  However, the dedicated device used in Patent Document 1 is expensive, and various dedicated devices are required when dealing with products having different shapes of the developing container and the toner regulating member, resulting in high costs.

  The present invention solves the above-described problems, and an object of the present invention is to develop with a simple configuration that can suppress a decrease in the contact pressure of the layer thickness regulating means in the longitudinal direction of the developer carrier. A device is provided.

  A typical configuration of the developing device according to the present invention for achieving the above object includes a developer containing unit that contains a developer, a developer carrying member that carries the developer in the developer containing unit, and a longitudinal direction. A layer thickness regulating means that is fixed to the developer containing unit in a predetermined direction at fixed positions on both sides of the direction and regulates the layer thickness of the developer carried on the developer carrier, and the layer thickness regulating means is pressed A pressing means having a region protruding in a direction parallel to the predetermined direction from a position pressing the fixed position between the fixed positions of the layer thickness regulating means with respect to the developer containing unit. And means.

  According to the present invention, it is possible to suppress a decrease in the contact pressure of the layer thickness regulating means in the longitudinal direction of the developer carrier with a simple configuration.

FIG. 2 is a cross-sectional explanatory view illustrating a configuration of an image forming apparatus including a developing device according to the present invention. FIG. 3 is an explanatory perspective view illustrating a configuration of a developing device according to the present invention. FIG. 2 is an explanatory cross-sectional view illustrating a configuration of a developing device according to the present invention. FIG. 3 is an explanatory perspective view showing a state in which a toner regulating member is attached to a container frame in a state before a developing sleeve is attached to the container frame of the developing device shown in FIG. 2. FIG. 4A is a perspective explanatory view illustrating a configuration of a toner regulating member viewed from above. (B) is a perspective explanatory view showing the configuration of the toner regulating member viewed from the back side. (A) is a perspective explanatory view showing the configuration of the upper lid of the container frame of the developing device of the first embodiment. (B) is a plane explanatory drawing which shows the structure of the upper cover of the container frame of the developing device of 1st Embodiment. FIG. 6 is a perspective explanatory view showing a state where an upper lid attached to a container frame is brought into contact with the back surface of a toner regulating member. (A) is a cross-sectional explanatory view showing a state in which the end portion in the longitudinal direction of the toner regulating member of the first embodiment is brought into contact with the surface of the developing sleeve. (B) is a cross-sectional explanatory view showing a state in which the central portion in the longitudinal direction of the toner regulating member of the first embodiment is brought into contact with the surface of the developing sleeve. FIG. 4 is a perspective view illustrating a configuration of an apparatus for measuring a contact pressure of a toner regulating member. (A) is a perspective explanatory drawing which shows the structure of the upper cover of 2nd Embodiment. (B) is a plane explanatory drawing which shows the structure of the upper cover of 2nd Embodiment. FIG. 10 is an explanatory cross-sectional view illustrating a state in which a central portion in a longitudinal direction of a toner regulating member according to a second embodiment is brought into contact with a surface of a developing sleeve. (A) is a perspective explanatory drawing which shows the structure of the upper cover attached to the container frame of the developing device of a comparative example. (B) is a plane explanatory drawing which shows the structure of the upper cover attached to the container frame of the developing device of a comparative example. FIG. 6A is a cross-sectional explanatory view illustrating a configuration of an end portion in a longitudinal direction of a toner regulating member of a comparative example. (B) is a cross-sectional explanatory view showing the configuration of the central portion in the longitudinal direction of the toner regulating member of the comparative example. (C) is a cross-sectional explanatory view showing a state in which the end portion in the longitudinal direction of the toner regulating member of the comparative example is brought into contact with the surface of the developing sleeve. (D) is a cross-sectional explanatory view showing a state in which the central portion in the longitudinal direction of the toner regulating member of the comparative example is brought into contact with the surface of the developing sleeve.

  An embodiment of an image forming apparatus provided with a developing device according to the present invention will be specifically described with reference to the drawings.

[First Embodiment]
The configuration of the first embodiment of the image forming apparatus including the developing device according to the present invention will be described with reference to FIGS.

<Image forming apparatus>
First, the configuration of the image forming apparatus 100 including the developing device 5 according to the present invention will be described with reference to FIG. FIG. 1 is an explanatory cross-sectional view showing a configuration of an image forming apparatus 100 including a developing device 5 according to the present invention. An image forming apparatus 100 shown in FIG. 1 is an image forming apparatus using an electrophotographic method. The image forming apparatus 100 includes a photosensitive drum 1 serving as an image carrier and a charging roller 2 serving as a charging unit that uniformly charges the surface of the photosensitive drum 1.

  Furthermore, the surface of the uniformly charged photosensitive drum 1 is exposed to light according to image information to form an electrostatic latent image to form an exposure device 4 serving as an image exposure unit. Further, the image forming apparatus includes a developing device 5 serving as a developing unit that supplies toner (developer) to the electrostatic latent image formed on the surface of the photosensitive drum 1 and develops the toner image. Furthermore, a transfer roller 7 serving as a transfer unit that transfers the toner image formed on the surface of the photosensitive drum 1 to the recording material P is provided. Further, a cleaner 10 is provided as a cleaning means for cleaning residual toner remaining on the surface of the photosensitive drum 1 after the transfer.

  The photosensitive drum 1 has a photosensitive layer on the surface of a cylindrical substrate. The photosensitive drum 1 rotates in the direction of arrow A in FIG. The charging roller 2 is applied with a charging bias from a charging bias power source (not shown) to uniformly charge the surface of the photosensitive drum 1. The exposure device 4 performs exposure corresponding to the image signal on the surface of the uniformly charged photosensitive drum 1 to form an electrostatic latent image on the surface of the photosensitive drum 1.

  The developing device 5 includes a developing sleeve 5a that is rotatably supported by a container frame 37 that constitutes a developer containing unit that contains toner as a developer, and serves as a developer carrying member that carries toner as a developer. ing. The developing device 5 visualizes the electrostatic latent image by supplying the toner carried on the surface of the developing sleeve 5a to the electrostatic latent image formed on the surface of the photosensitive drum 1 and developing it as a toner image. .

  The developing device 5 detects the remaining amount of toner as the developer in the container frame 37 using the antenna electrode 33 provided in the container frame 37 (in the developer accommodating unit). As shown in FIG. 3, an electric resistance 40 is connected in series between the antenna electrode 33 and the ground G. The control unit 101 serving as a control unit detects a current flowing through the electric resistance 40 and develops based on a capacitance formed between the toner (developer) accommodated in the developing chamber 3 and the antenna electrode 33. The toner amount (developer amount) accommodated in the chamber 3 is detected.

  The transfer roller 7 is driven by a transfer bias power source (not shown) in the process of nipping and conveying the recording material P conveyed in synchronism with the operation of forming the toner image on the surface of the photosensitive drum 1 with the surface of the photosensitive drum 1. A transfer bias is applied. As a result, the toner image formed on the surface of the photosensitive drum 1 is transferred to the recording material P. The cleaner 10 removes and removes transfer residual toner remaining on the surface of the photosensitive drum 1 after transfer, paper dust and the like transferred from the recording material P to the surface of the photosensitive drum 1 by the cleaning blade 10a.

<Developing device>
Next, the configuration of the developing device 5 will be described with reference to FIGS. FIG. 2 is an explanatory perspective view showing the configuration of the developing device 5. FIG. 3 is a cross-sectional explanatory view showing the configuration of the developing device 5. The developing device 5 shown in FIGS. 2 and 3 includes a container frame 37 that forms a developer storage unit that stores toner (developer), and a developer carrier that is rotatably supported by the container frame 37. A developing sleeve 5a. Further, a developing bias power source 6 for applying a developing bias to the developing sleeve 5a is provided. The developing bias power source 6 is controlled by a control unit 101 serving as a control unit. Furthermore, an antenna electrode 33 for detecting the amount of toner (developer amount) in the developing chamber 3 provided with the developing sleeve 5a is provided.

  Furthermore, the stirring chamber 8 has a toner bottle 34 for supplying toner (developer). Further, a toner regulating member 35 serving as a layer thickness regulating means for regulating the layer thickness of the toner (developer) carried on the surface of the developing sleeve 5a (developer carrying body) is provided. The toner regulating member 35 (layer thickness regulating means) is a screw 286 serving as a fixing means in which both ends in the longitudinal direction are screwed and fastened into screw holes 37a and 37b provided in the container frame 37 (developer housing unit). It is fixed with screws.

  Furthermore, it has a stirring member 36 a that is rotatably supported by the container frame 37 and stirs the toner (developer) in the toner bottle 34 and transports it into the stirring chamber 8. Further, it has a stirring member 36 b that is rotatably supported by the container frame 37 and stirs the toner (developer) in the stirring chamber 8 and conveys it into the developing chamber 3. Furthermore, it has a stirring member 36c that is rotatably supported by the container frame 37 and stirs the toner (developer) in the developing chamber 3 and conveys it to the developing sleeve 5a.

<Developer carrier>
The developing sleeve 5a, which is a developer carrier, is rotatably attached to the container frame 37 and rotates in the direction of arrow B in FIG. The developing sleeve 5a carries toner accommodated in the developing chamber 3 formed by the container frame 37, and supplies the toner to the surface of the photosensitive drum 1 facing the developing sleeve 5a.

<Development bias power supply>
The developing bias power source 6 applies a developing bias voltage (bias signal) obtained by superimposing a DC voltage and an AC voltage to the developing sleeve 5a. As a result, the toner coated on the surface of the developing sleeve 5 a is caused to fly toward the electrostatic latent image formed on the surface of the photosensitive drum 1. As a result, the electrostatic latent image formed on the surface of the photosensitive drum 1 is developed as a toner image.

<Developer supply container>
A toner bottle 34 as a developer supply container is detachably attached to the container frame 37. When the toner in the toner bottle 34 becomes empty, the user can replace the toner bottle 34 with a new one. The toner bottle 34 replenishes the toner into the stirring chamber 8 before the toner in the developing chamber 3 formed by the container frame 37 is completely removed.

<Stirring member>
The agitating members 36a to 36c convey the toner in the container frame 37 toward the developing sleeve 5a by sequentially agitating and conveying the toner in the container frame 37 from the toner bottle 34 to the agitating chamber 8 and the developing chamber 3. .

<Developer storage unit>
A container frame 37 serving as a developer storage unit that stores toner (developer) forms a frame of the developing device 5. The container frame 37 stores toner inside so as to enable continuous image forming operations. Yes. The toner stored in the container frame 37 is consumed when the image forming operation of the image forming apparatus 100 is performed.

<Layer thickness regulating means>
Next, the configuration of the toner regulating member 35 serving as the layer thickness regulating means will be described with reference to FIGS. FIG. 4 is a perspective explanatory view showing a state in which the toner regulating member 35 is attached to the container frame 37 before the developing sleeve 5a is attached to the container frame 37 of the developing device 5 shown in FIG. FIG. 5A is an explanatory perspective view showing the configuration of the toner regulating member 35 as viewed from above. FIG. 5B is a perspective explanatory view showing the configuration of the toner regulating member 35 viewed from the back side.

  As shown in FIG. 4, the toner regulating member 35 serving as the layer thickness regulating means shown in FIG. 3 has a container frame 37 (developer housing) in a predetermined direction at a fixed position screwed by screws 286 on both sides in the longitudinal direction. The layer thickness of the toner (developer) carried on the surface of the developing sleeve 5a (developer carrier) is regulated. The toner regulating member 35 is in contact with the surface of the developing sleeve 5a with a predetermined pressure. As a result, a uniform toner layer is formed on the surface of the developing sleeve 5a. The toner regulating member 35 conveys the toner while sandwiching the toner with the surface of the developing sleeve 5a rotating in the direction of arrow B in FIG. As a result, the toner is charged with a constant charge by frictional charging between the toner and the surface of the developing sleeve 5a.

  As shown in FIG. 8B, the toner regulating member 35 (layer thickness regulating means) has an abutting member 281 that abuts on and contacts the surface of the developing sleeve 5a (developer carrier). The contact member 281 is sandwiched and supported by the support member 283 and the second support member 284. A pressing member 282 is provided on the opposite side of the contact surface of the contact member 281 with the developing sleeve 5a. The pressing member 282 is fixed to a second support member 284 having an L-shaped cross section. The pressing member 282 presses the contact member 281 against the surface of the developing sleeve 5a (developer carrier).

<Pressing means>
As shown in FIG. 2, an upper lid 300 serving as a lid member that presses the toner regulating member 35 (layer thickness regulating means) is attached to the upper portion of the container frame 37 (developer housing unit). The upper lid 300 (pressing means) serving as a lid member is between fixed positions where screws are fixed by screws 286 on both sides in the longitudinal direction with respect to the container frame 37 (developer storage unit) of the toner regulating member 35 (layer thickness regulating means). Thus, it has a region protruding in a direction parallel to a predetermined direction (downward direction in FIG. 6B) from the position where the fixed position is pressed. As shown in FIG. 8B, the upper lid 300 (pressing means) serving as a lid member presses the pressing member 282 against the surface of the developing sleeve 5a (developer carrier) via the second support member 284. . As a result, the upper lid 300 (pressing means) presses the toner regulating member 35 (layer thickness regulating means) against the surface of the developing sleeve 5a (developer carrier) with a predetermined pressing force in the following direction. The direction in which the upper lid 300 (pressing means) presses is parallel to the direction in which the toner restricting member 35 (layer thickness restricting means) is attached to the container frame 37 (developer containing unit) (the left-right direction in FIG. 8B). (In the direction of arrow D in FIG. 8B). As shown in FIGS. 6A and 6B, the upper lid 300 (lid member) has a contact pressure adjusting hole 301 which is a long slot along a predetermined direction (vertical direction in FIG. 6B). Is provided. The upper lid 300 (lid member) is screwed and fixed to the container frame 37 (developer housing unit) through the contact pressure adjusting hole 301 (long hole). Thus, the pressing force for pressing the toner regulating member 35 (layer thickness regulating means) against the surface of the developing sleeve 5a (developer carrying member) can be adjusted.

  As shown in FIG. 8B, the toner regulating member 35 (layer thickness regulating means) includes a contact member 281 that contacts the surface of the developing sleeve 5a (developer carrier) and a support that supports the corresponding contacting member 281. A member 283 and a second support member 284, and a pressing member 282 that presses the contact member 281 against the surface of the developing sleeve 5a (developer carrier). The upper lid 300 (lid member) presses the second support member 284 against the contact member 281. The materials of the contact member 281, the pressing member 282, the supporting member 283, and the second supporting member 284 are selected so as to satisfy the toner layer thickness regulation on the surface of the developing sleeve 5a and charging requirements. For example, the pressing member 282, the supporting member 283, and the second supporting member 284 are selected from metal, and the abutting member 281 is an elastic plate member made of resin, elastic rubber material, or the like. In the present embodiment, SUS (stainless steel) is used for the pressing member 282, the supporting member 283, and the second supporting member 284, and urethane resin is used for the contact member 281.

  The thickness of the contact member 281 is 1 mm. The thickness of the second support member 284 is 1 mm. The thickness of the pressing member 282 is 0.05 mm. The thickness of the support member 283 is 1.2 mm. The length of the contact member 281 in the longitudinal direction is 300 mm. The width of the contact member 281 in the short direction is 18 mm.

  The lengths of the pressing member 282 and the second support member 284 in the longitudinal direction are both 300 mm, and preferably the same size as the length of the contact member 281 in the longitudinal direction. The materials and sizes of the contact member 281, the pressing member 282, the support member 283, and the second support member 284 are not limited to these, and the toner layer thickness regulation on the surface of the developing sleeve 5 a and the charging As long as it can meet the requirements of

  As shown in FIG. 5A, the contact member 281, the pressing member 282, the support member 283, and the second support member 284 are fastened and fixed by screws 285 serving as fixing means and an adhesive. The configuration of the toner regulating member 35 is not limited to this, and for example, the pressing member 282 and the second support member 284 are omitted, and the screw 285 and the adhesive serving as a fixing means for the contact member 281 to the support member 283. It may be fastened and fixed.

  As shown in FIG. 4, the toner regulating member 35 is attached to a container frame 37 of the developing device 5 provided in the main body of the image forming apparatus 100. A second through hole 137a serving as a fixing portion provided at one end portion in the longitudinal direction of the support member 283 having an L-shaped cross section of the toner regulating member 35 and a through hole 137b serving as a fixing portion provided at the other end portion are secondly provided. A screw 286 serving as a fixing means is inserted. Then, a screw hole 37a provided at one end in the longitudinal direction of the container frame 37 and a screw hole 37b provided at the other end are respectively screwed and fastened. As a result, the toner regulating member 35 is fixed to the container frame 37.

  FIG. 6A is a perspective explanatory view showing the configuration of the upper lid 300 of the container frame 37 of the developing device 5. FIG. 6B is an explanatory plan view showing the configuration of the upper lid 300 of the container frame 37 of the developing device 5. An upper lid 300 shown in FIG. 6A is a container frame of the developing device 5 by inserting a screw 11 serving as a fixing means into an abutting pressure adjusting hole 301 formed of a long hole in a through hole provided at the periphery of the upper lid 300. It is fixed by screwing into a screw hole provided in the body 37.

  The contact pressure adjusting hole 301 is a long hole that extends in the direction in which the toner regulating member 35 (layer thickness regulating means) is pressed against the developing sleeve 5a (developer carrier). Therefore, the fixing position of the upper lid 300 can be adjusted by the length in the longitudinal direction of the long hole of the contact pressure adjusting hole 301. The upper lid 300 is inserted into the elongated hole of the contact pressure adjusting hole 301 and screwed into a screw hole provided in the container frame 37 (developer housing unit) to be fixed with screws. Thus, the pressing force of the toner regulating member 35 (layer thickness regulating means) against the developing sleeve 5a (developer carrying member) can be adjusted.

  FIG. 7 is an explanatory perspective view illustrating a state in which the upper lid 300 attached to the container frame 37 is brought into contact with the back surface of the toner regulating member 35. The upper lid 300 is pushed in the direction of the arrow D in FIG. 7 at the central portion 37c in the longitudinal direction of the container frame 37 of the developing device 5 so as to enter the back side of the toner regulating member 35 and contact it. As a result, the contact pressure of the toner regulating member 35 with respect to the surface of the developing sleeve 5a at the longitudinal center 37c of the container frame 37 can be adjusted. By applying a force to push the upper lid 300 in the direction of arrow D in FIG. 7, the force with which the contact member 281 of the toner regulating member 35 contacts the surface of the developing sleeve 5a can be improved.

  FIG. 8A is an explanatory cross-sectional view showing a state in which the end portion of the toner regulating member 35 in the longitudinal direction is brought into contact with the surface of the developing sleeve 5a. FIG. 8B is a cross-sectional explanatory view showing a state in which the central portion of the toner regulating member 35 in the longitudinal direction is brought into contact with the surface of the developing sleeve 5a. As shown in FIGS. 8A and 8B, the flat surface portion of the abutting member 281 of the toner regulating member 35 hits against the surface of the developing sleeve 5a in the counter direction with respect to the rotation direction of the developing sleeve 5a. Contact with. At this time, after the contact member 281 is deformed and contacts the surface of the developing sleeve 5a, the back surface 281a of the contact member 281 and the pressing member 282 come into contact with each other.

  Therefore, the distortion as the elastic member of the contact member 281 itself can be corrected along the surface of the developing sleeve 5a without being affected by the pressing force of the pressing member 282. In this way, after the distortion of the contact member 281 is corrected, it is pressed by the pressing member 282. Accordingly, the contact member 281 is pressed against the surface of the developing sleeve 5a and rubs so as not to be affected by the distortion of the contact member 281 as much as possible. Then, a state in which a thin toner layer having a uniform thickness is applied on the surface of the developing sleeve 5a on the downstream side in the rotation direction of the developing sleeve 5a from the contact position of the contact member 281 is formed.

<Comparative example>
Next, the configuration of the comparative example will be described with reference to FIGS. FIG. 12A is a perspective explanatory view showing the configuration of the upper lid 300 attached to the container frame 37 of the developing device 5 of the comparative example. FIG. 12B is an explanatory plan view showing the configuration of the upper lid 300 attached to the container frame 37 of the developing device 5 of the comparative example.

  FIG. 13A is a cross-sectional explanatory view showing the configuration of the end portion in the longitudinal direction of the toner regulating member 35 of the comparative example. FIG. 13B is a cross-sectional explanatory view showing the configuration of the central portion in the longitudinal direction of the toner regulating member 35 of the comparative example. FIG. 13C is an explanatory cross-sectional view showing a state in which the end portion in the longitudinal direction of the toner regulating member 35 of the comparative example is brought into contact with the surface of the developing sleeve 5a. FIG. 13D is a cross-sectional explanatory view showing a state in which the central portion in the longitudinal direction of the toner regulating member 35 of the comparative example is brought into contact with the surface of the developing sleeve 5a.

  In the toner regulating member 35 of the comparative example shown in FIG. 12 and FIG. 13, the upper lid 300 faces the second support member 284 in the longitudinal center portion 37c of the container frame 37 as shown in FIG. However, it is not a structure that makes positive contact. In the gap 9 between the upper lid 300 and the second support member 284, there is a soft sponge-like member (not shown) for preventing toner leakage.

  As shown in FIG. 13D, when the contact member 281 contacts the surface of the developing sleeve 5a, the toner regulating member 35 is pushed in the direction of the upper lid 300. Therefore, the distance between the upper lid 300 and the second support member 284 on the back side of the toner regulating member 35 is such that the sponge-like member is contracted and the gap 9 is narrowed. As a result, the force with which the contact member 281 presses the surface of the developing sleeve 5a escapes, and the contact pressure with which the contact member 281 contacts the surface of the developing sleeve 5a is reduced.

  On the other hand, in the vicinity of the end portion of the toner regulating member 35 in the longitudinal direction, as shown in FIG. 13C, the through holes 137a and 137b serving as the fixing portions at the longitudinal end portion of the support member 283 serve as the second fixing means. Screw 286 is inserted. The container frame 37 is fixed by screwing into a screw hole 37a provided at one end in the longitudinal direction of the container frame 37 and a screw hole 37b provided at the other end. For this reason, as shown in FIG. 13C, even when the contact member 281 contacts the surface of the developing sleeve 5a, the force by which the contact member 281 presses the surface of the developing sleeve 5a is difficult to escape, and the contact member 281 The contact pressure that contacts the surface of the developing sleeve 5a is easily maintained.

  As shown in FIG. 13D, the contact pressure at which the contact member 281 contacts the surface of the developing sleeve 5a at the longitudinal center portion 37c of the container frame 37 is considered. Further, the contact member 281 is in contact with the surface of the developing sleeve 5a near the screw hole 37a provided at one end portion in the longitudinal direction of the container frame 37 and the screw hole 37b provided at the other end portion. Consider pressure. When both are compared, the contact pressure at which the contact member 281 contacts the surface of the developing sleeve 5a is different.

  In the central portion 37c in the longitudinal direction of the container frame 37, when the contact member 281 comes into contact with the surface of the developing sleeve 5a, the force with which the contact member 281 presses the surface of the developing sleeve 5a is the direction of arrow E in FIG. It is easy to escape. For this reason, the contact pressure with which the contact member 281 contacts the surface of the developing sleeve 5a tends to decrease. Therefore, there is a difference in the contact pressure at which the contact member 281 contacts the surface of the developing sleeve 5a between the vicinity of the end in the longitudinal direction and the vicinity of the center of the toner regulating member 35 of the comparative example.

  As shown in FIGS. 12A and 12B, the upper lid 300 is inserted into the container frame 37 of the developing device 5 by inserting a screw 11 as a fixing means into a fixing hole 302 formed of a round hole provided at the periphery. It is fixed by screwing into a provided screw hole. The fixing hole 302 of the comparative example is not a long hole like the contact pressure adjusting hole 301 of the present embodiment shown in FIGS. 6A and 6B but a circular round hole. Therefore, unlike the present embodiment shown in FIG. 7, the position of the upper lid 300 cannot be adjusted by pushing the upper lid 300 in the direction of arrow D in FIG. 7 and entering the back side of the toner regulating member 35. For this reason, it is not possible to adjust the contact pressure of the toner regulating member 35 on the surface of the developing sleeve 5a at the central portion 37c in the longitudinal direction of the container frame 37 as in this embodiment.

  In the present embodiment, as shown in FIG. 6B, the contact portion 300 a that enters the back side of the toner regulating member 35 of the upper lid 300 has a central portion in the longitudinal direction of the upper lid 300 facing the second support member 284. It protrudes. That is, the central portion in the longitudinal direction of the upper lid 300 (lid member) protrudes in a direction to press the toner regulating member 35 (layer thickness regulating means) against the surface of the developing sleeve 5a (developer carrying member). As a result, the central contact portion 300 a in the longitudinal direction of the upper lid 300 can positively contact the second support member 284 provided on the back side of the toner regulating member 35.

  As a result, the upper lid 300 is pushed in the direction of arrow D in FIG. 8B to enter the back side of the toner regulating member 35 to apply force. As a result, a force is applied from the contact portion 300a to the second support member 284 provided on the back side of the toner regulating member 35, and the gap 9 is eliminated. Then, the force in the direction of arrow D in FIG. 8B is transmitted to the contact member 281. As a result, the contact pressure of the contact member 281 provided on the toner regulating member 35 with the surface of the developing sleeve 5a is improved.

  The pressing force for pressing the toner regulating member 35 (layer thickness regulating means) against the surface of the developing sleeve 5a (developer carrying member) at the longitudinal center of the upper lid 300 (pressing means) is as follows. It is larger than the pressing force against the surface of the developing sleeve 5a (developer carrier) at the end in the longitudinal direction of the toner regulating member 35 (layer thickness regulating means) fixed to the container frame 37 (developer containing unit) with screws.

  In this embodiment, a contact pressure measuring device 400 shown in FIG. 9 is used to make the contact pressure of the contact member 281 provided on the toner regulating member 35 uniform with the surface of the developing sleeve 5a. The contact pressure measuring device 400 shown in FIG. 9 uses a load cell system in which a force is applied to convert it into an electrical signal and the output is digitally displayed. In the load cell system, there are various types of elastic bodies called strain bodies, such as springs, piezo elements, compression elements, and the like, but those types are not limited as long as the contact pressure can be measured.

  As shown in FIG. 4, the toner regulating member is attached to the first to third measuring portions 401 to 403 of the contact pressure measuring device 400 shown in FIG. 9 with the toner regulating member 35 attached to the container frame 37 of the developing device 5. The 35 contact members 281 are set so as to contact each other. The respective measured values of the first to third measuring units 401 to 403 are confirmed. First, the measured values of the first and third measuring units 401 and 403 for measuring both longitudinal ends of the contact member 281 are determined. The fastening of the screw 286 shown in FIG. 4 is adjusted so that the same contact pressure is within the product standard.

  Next, the measurement values of the second measuring unit 402 that measures the longitudinal center of the contact member 281 are the first and third measurement units 401 and 403 that measure both longitudinal ends of the contact member 281 after adjustment. To match the measured value of. That is, the upper lid 300 is pushed in the direction of arrow D in FIG. 7 to enter the back side of the toner regulating member 35. Then, as shown in FIG. 8B, the contact portion 300 a of the upper lid 300 is brought into contact with the second support member 284 provided on the back side of the toner regulating member 35. Further, a force is applied to the upper lid 300 to push the second support member 284 provided on the back side of the toner regulating member 35 in the longitudinal center portion 37c of the container frame 37 in the direction of arrow D in FIG.

  The measurement value of the second measurement unit 402 that measures the longitudinal center of the contact member 281 is the measurement value of the first and third measurement units 401 and 403 that measure both longitudinal ends of the contact member 281 after adjustment. Matches. At that time, the screw 11 as a fixing means is inserted into the contact pressure adjusting hole 301 shown in FIGS. 8A and 8B and screwed into the screw hole provided in the container frame 37 of the developing device 5. The upper lid 300 is fixed to the container frame 37.

  In this embodiment, as shown in FIG. 8B, the contact state in which the contact portion 300 a of the upper lid 300 contacts the second support member 284 provided on the back side of the toner regulating member 35 is adjusted. As a result, the contact pressure that contacts the surface of the developing sleeve 5 a can be made uniform over the entire length of the contact member 281 of the toner regulating member 35.

  After the contact pressure that contacts the surface of the developing sleeve 5a becomes uniform over the entire length of the contact member 281 of the toner regulating member 35, as shown in FIG. 2, the container frame 37 of the developing device 5 is used. Assemble parts such as the developing sleeve 5a. The completed developing device 5 is attached to the main body of the image forming apparatus 100 for use.

  In the present embodiment, the toner regulating member 35 (layer thickness regulating means) is formed by the upper lid 300 (pressing means) in a direction parallel to the mounting direction of the toner regulating member 35 (layer thickness regulating means) (left and right direction in FIG. 8B). Is pressed toward the surface of the developing sleeve 5a (developer carrier) with a predetermined pressing force. As a result, the pressing force at the center in the longitudinal direction of the upper lid 300 (pressing means) is caused by the pressing force that fixes both ends in the longitudinal direction of the toner regulating member 35 (layer thickness regulating means) to the container frame 37 (developer housing unit). Is also big.

  As a result, both end portions in the longitudinal direction of the toner regulating member 35 (layer thickness regulating means) are fixed to the container frame 37 (developer housing unit) with screws. At that time, the pressing force at the longitudinal center of the upper lid 300 (pressing means) increases. Accordingly, a position away from both longitudinal ends of the toner restricting member 35 (layer thickness restricting means) fixed to the container frame 37 (developer containing unit) by screwing is considered. Even in such a position, it is possible to prevent the pressing force that presses the toner regulating member 35 (layer thickness regulating means) against the surface of the developing sleeve 5a (developer carrier) due to durability.

  In this embodiment, the pressing direction indicated by the arrow D direction in FIG. 8B in which the contact member 281 of the toner regulating member 35 presses the surface of the developing sleeve 5a is considered. And the fixing direction shown by the arrow D direction of FIG.8 (b) which fixes the upper cover 300 (pressing means) is considered. Both directions are the same direction. For this reason, a decrease in the pressing force with which the contact member 281 of the toner regulating member 35 presses the surface of the developing sleeve 5a is reduced.

[Second Embodiment]
Next, the configuration of the second embodiment of the image forming apparatus including the developing device according to the present invention will be described with reference to FIGS. 10 and 11. In addition, what was comprised similarly to the said 1st Embodiment attaches | subjects the same member name even if the same code | symbol or a code | symbol differs, and abbreviate | omits description. FIG. 10A is a perspective explanatory view showing the configuration of the upper lid 300 of the second embodiment. FIG. 10B is an explanatory plan view showing the configuration of the upper lid 300 of the second embodiment. FIG. 11 is an explanatory cross-sectional view showing a state in which the central portion in the longitudinal direction of the toner regulating member 35 of the second embodiment is brought into contact with the surface of the developing sleeve 5a.

  As shown in FIGS. 10A and 10B, the upper lid 300 of this embodiment serves as a fixing means for the contact pressure adjusting hole 301 that is a long hole formed in a through hole provided in the peripheral portion of the upper lid 300. Insert the screw 11. And it fixes by screwing and fastening to the screw hole provided in the container frame 37 of the developing device 5. The contact pressure adjusting hole 301 is formed of a long hole. Therefore, the fixing position of the upper lid 300 can be adjusted by the length of the long hole of the corresponding contact pressure adjusting hole 301.

  The contact portion 300a that pushes the upper lid 300 in the direction of arrow D in FIG. 11 and enters the back side of the toner regulating member 35 has a gentle curved surface shape as shown in FIG. The contact portion 300 a at the center in the longitudinal direction of the upper lid 300 protrudes most toward the second support member 284 provided on the back surface side of the toner regulating member 35.

  When the contact part 300a of the upper lid 300 comes into contact with the second support member 284 provided on the back side of the toner regulating member 35 in the longitudinal center part 37c of the container frame 37 shown in FIG. In the longitudinal direction, it is easy to make contact with a surface instead of a point. Therefore, the force in the direction of arrow D in FIG. 11 is likely to be applied equally from the contact portion 300a of the upper lid 300 to the second support member 284, and the toner regulating member 35 can be supported stably.

  The second support member 284 of the present embodiment is provided with a fitting portion 284a having a U-shaped cross section into which the contact portion 300a of the upper lid 300 is fitted. The upper lid 300 of this embodiment is provided with a contact portion 300b made of a convex portion in addition to the contact portion 300a. The contact part 300b abuts and slides on the lower surface 284b1 of the horizontal part 284b of the second support member 284. The contact part 300 a of the upper lid 300 is fitted into the fitting part 284 a of the second support member 284.

  Then, consider the case where the contact member 281 of the toner regulating member 35 contacts the surface of the developing sleeve 5a at the central portion 37c in the longitudinal direction of the container frame 37 and is pushed back toward the upper lid 300. At this time, a case is considered in which a force that pushes back the toner regulating member 35 not only in the horizontal direction (left direction in FIG. 11) but also in the vertical direction (upward direction in FIG. 11) is applied. The upper lid 300 is pushed in the direction of arrow D in FIG. 11 to enter the back side of the toner regulating member 35. At this time, the force of the contact portion 300a pressing the second support member 284 is difficult to escape, and the contact pressure at which the contact member 281 of the toner regulating member 35 contacts the surface of the developing sleeve 5a is easily maintained.

  As shown in FIG. 11, the second support member 284 is provided with a fitting portion 284a, and the upper lid 300 is provided with contact portions 300a and 300b having a reverse T-shaped cross section so that the toner regulating member 35 can be seen from the back side. It can be supported more stably. Other configurations are the same as those in the first embodiment, and the same effects can be obtained. In the present invention, the type, shape, arrangement, number, and the like of the members are not limited to the above-described embodiments, and the constituent elements can be appropriately replaced with those having the same effects.

5a: Development sleeve (developer carrier)
35. Toner regulating member (layer thickness regulating means)
37 ... Container frame (developer housing unit)
300 ... Upper lid (lid member; pressing means)

Claims (5)

A developer accommodating unit for accommodating the developer;
A developer carrying member carrying the developer in the developer containing unit;
A layer thickness regulating means that is fixed to the developer containing unit in a predetermined direction at fixed positions on both sides in the longitudinal direction and regulates the layer thickness of the developer carried on the developer carrier;
A pressing unit that presses the layer thickness regulating unit, and is a direction parallel to the predetermined direction rather than a position that presses the fixed position between the fixed positions of the layer thickness regulating unit with respect to the developer containing unit. Pressing means having a protruding region;
A developing device comprising: The pressing means is
The developing device according to claim 1, wherein the developing device is a lid member attached to an upper portion of the developer containing unit. The lid member is
A long slot is provided along the predetermined direction,
By being screwed and fixed to the developer accommodating unit through the elongated hole, the pressing force for pressing the layer thickness regulating means against the developer carrying member can be adjusted. The developing device according to claim 2. The layer thickness regulating means is
A contact member in contact with the developer carrier;
A support member for supporting the contact member;
A pressing member that presses the contact member against the developer carrier;
Have
The developing device according to claim 2, wherein the lid member presses the support member against the contact member. An image carrier;
A developing device according to any one of claims 1 to 4,
An image forming apparatus comprising:

Images