JP2023080678A - developing device - Google Patents

Abstract

To release pressure of a regulation blade with a simple configuration.SOLUTION: A developing device includes: a developing roller 32 that retains a developing agent stirred by an impeller in a stirring chamber; a filling inlet located at an end side of the stirring chamber in an axial direction of the impeller and opened in the axial direction; a support portion that supports an axis of the impeller at the inside of the filling inlet; a regulation blade 40 opposed to an outer circumferential surface of the developing roller 32; a biasing member 46 that presses the regulation blade 40 against the developing roller 32; a switching member 50 that switches between a release state in which the switching member releases pressure of the regulation blade 40 against the developing roller 32 while resisting the biasing member 46 and a pressing state in which the switching member presses the regulation blade 40 against the developing roller 32 while not resisting the biasing member 46; and a first fitting portion 61 into which the switching member 50 is fitted in the release state.SELECTED DRAWING: Figure 7

Description

The present invention relates to a developing device that develops a latent image with developer.

An electrophotographic image forming apparatus includes a developing device that develops a latent image using a developer. The developing device includes an impeller that agitates the developer contained in the agitating chamber, a developing roller that faces the photosensitive drum and holds the agitated developer, and a layer thickness of the developer held by the developing roller is regulated. and a regulating blade. As an example of technology related to the regulating blade, a configuration in which the regulating blade is pressed against the developing roller is known (for example, Patent Documents 1 to 4).

Japanese Patent Application Laid-Open No. 4-465 JP-A-5-27579 JP-A-6-83172 JP-A-6-342238

By the way, a developing device that also serves as a developer cartridge is known. Specifically, a developing device filled with developer is supplied to the user, and when the developer runs out due to printing, the developing device is replaced with another developing device filled with developer. Empty developer units are collected, filled with developer at the factory, and then supplied to users.

Regarding the filling of the developer, there are problems to be solved in the case of the structure shown below. As described above, the impeller is provided in the stirring chamber of the developing device. A filling port opening in the axial direction is provided at one end of the stirring chamber in the axial direction of the impeller. The developing device is fixed by a jig with the filling port facing upward, a container containing developer is connected to the filling port, and the developer is dropped. However, since a support for supporting the shaft of the impeller is provided inside the filling port, there arises a problem that the developer falls on the support and accumulates thereon.

In order to prevent the developer from accumulating on the supporting portion, it is conceivable to use a vibrator to vibrate the developing device fixed by a jig while dropping the developer. However, if the regulating blade is kept pressed against the developing roller, the regulating blade and the developing roller rub against each other, damaging the surface of the developing roller.

In order to prevent damage to the developing roller, it is effective to move the regulating blade away from the developing roller. The configurations described in Patent Documents 1 to 4 can move the regulating blade away from the developing roller. However, in the configuration described in Patent Document 1, it is necessary to manually press the regulating blade during developer filling. The configuration described in Patent Document 2 uses an electromagnet to move the regulating blade, and the configuration described in Patent Document 3 uses a motor and a cam to move the regulating blade. also requires power. The configuration described in Patent Document 4 moves the regulating blade by deforming the shape memory alloy with the heat of the fixing device.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a developing device capable of releasing the pressing force of a regulating blade with a simple structure.

In order to solve the above problems, a developing device according to the present invention includes a stirring chamber containing a developer, an impeller for stirring the developer contained in the stirring chamber, and a developer stirred by the impeller. a developing roller holding a developing roller, a filling port opened in the axial direction on one end side of the stirring chamber in the axial direction of the impeller, and a support portion supporting the shaft of the impeller inside the filling port; a regulating blade facing the outer peripheral surface of the developing roller; an urging member that presses the regulating blade against the developing roller; a switching member that is switched between a released state and a pressing state in which the regulating blade is pressed against the developing roller by not resisting the biasing member; and a first fitting portion into which the switching member is fitted in the released state. And prepare.

The switching member includes a central portion rotatably supported on a shaft parallel to the developing roller, and a first projecting portion and a second projecting portion projecting in different radial directions from the central portion. In the state, the first projecting portion resists the urging member and pushes back the regulating blade to release the pressing of the regulating blade against the developing roller, and the second projecting portion pushes back the regulating blade. It may be configured to be fitted into one fitting portion.

The developing device may include a second fitting portion into which the second projecting portion fits in the pressed state.

The second projecting portion has flexibility, so that it can It may be configured such that the shape changes between the state in which it does not occur.

In the released state, the first projecting portion may be configured to push back the regulating blade to a position where it contacts the developing roller and does not bite into the developing roller.

The switching member includes a third projecting portion projecting toward the axis of the developing roller, the developing roller includes a developing roller projecting portion radially projecting from the axis of the developing roller, and the developing roller is driven. In this case, the developing roller projecting portion may push away the third projecting portion, thereby switching the switching member from the released state to the pressed state.

In the pressing state, the tip of the first protrusion and the tip of the third protrusion may be configured to be positioned outside the trajectory of the tip of the developing roller protrusion.

According to the present invention, it is possible to release the pressing of the regulating blade with a simple configuration.

1 is a perspective view showing the appearance of a printer according to an embodiment of the invention; FIG. 1 is a left side view schematically showing the internal configuration of a printer according to an embodiment of the invention; FIG. 1 is a perspective view showing the appearance of a developing device according to an embodiment of the invention; FIG. 3 is a right side view of the developing device according to one embodiment of the present invention; FIG. 3 is a perspective view showing the right end portion of the developing device according to one embodiment of the present invention; FIG. 3 is a perspective view showing how the developing device according to one embodiment of the present invention is held by a jig; FIG. 1 is a perspective view showing the internal configuration of a developing device according to an embodiment of the invention; FIG. 4 is a cross-sectional view of the developing device in a pressed state according to one embodiment of the present invention; FIG. 4 is a cross-sectional view of the developing device in a pressed state according to one embodiment of the present invention; FIG. 3 is a cross-sectional view of the developing device in a released state according to one embodiment of the present invention; FIG. 3 is a cross-sectional view of the developing device in a released state according to one embodiment of the present invention; FIG. FIG. 5 is a cross-sectional view of a developing device according to a modification of one embodiment of the present invention; FIG. 5 is a cross-sectional view of a developing device according to a modification of one embodiment of the present invention;

A printer 1 (an example of an image forming apparatus) according to an embodiment of the present invention will be described below with reference to the drawings.

First, the overall configuration of the printer 1 will be described. FIG. 1 is a perspective view showing the appearance of the printer 1. FIG. FIG. 2 is a left side view schematically showing the internal configuration of the printer 1. As shown in FIG. Hereinafter, the Fr side in FIGS. 1 and 2 is defined as the front side (front side) of the printer 1, and the left and right directions are based on the direction when the printer 1 is viewed from the front. In each figure, U, Lo, L, R, Fr, and Rr indicate up, down, left, right, front, and rear, respectively.

The printer 1 includes a rectangular parallelepiped body housing 3 . A paper feed tray 4 on which sheets S are stacked and a paper feed roller 5 for sending out the sheets S from the paper feed tray 4 are provided in the lower part inside the main body housing 3 . A cover 3C that can be opened and closed with a hinge 3H provided at the rear end as a fulcrum is provided on the upper portion of the body housing 3. As shown in FIG. An image forming device 6 for electrophotographic toner image formation is provided above the paper feed tray 4, and a fixing device 7 for fixing the toner image onto the sheet S is provided above the image forming device 6. ing. A discharge roller 8 is provided in front of the fixing device 7 to discharge the sheet S on which the toner image is fixed. A discharge tray 9 on which discharged sheets S are stacked is provided on the cover 3C.

Inside the body housing 3, a transport path 10 is provided from the paper feed roller 5 to the paper discharge roller 8 via the image forming device 6 and the fixing device 7. As shown in FIG. The conveying path 10 is mainly formed of plate-shaped members facing each other with a gap through which the sheet S passes. It is A registration roller 18 is provided upstream of the imaging device 6 in the transport direction Y. As shown in FIG.

The image forming device 6 includes a photoreceptor drum 11 whose potential changes when irradiated with light, a charging device 12 that charges the photoreceptor drum 11 by discharging, an exposure device 13 that emits a laser beam according to image data, and a photoreceptor drum 11 . Developing device 14 for supplying toner to and transfer roller 15 for generating transfer bias.

The control unit 2 includes an arithmetic unit and a storage unit. The calculation unit is, for example, a CPU (Central Processing Unit). The storage unit includes storage media such as ROM (Read Only Memory), RAM (Random Access Memory), and EEPROM (Electrically Erasable Programmable Read Only Memory). The calculation unit performs various processes by reading and executing the control program stored in the storage unit. Note that the control unit 2 may be realized only by an integrated circuit without using software.

A display operation unit 19 is provided on the upper surface of the main body housing 3 . The display operation unit 19 includes an indicator lamp and push buttons. The control unit 2 lights an indicator lamp according to the status of the printer 1 and controls each unit of the printer 1 according to the operation detected by the push button.

A basic image forming operation of the printer 1 is as follows. When a print job is input to the printer 1 from an external computer or the like, the paper feed roller 5 feeds the sheet S from the paper feed tray 4 to the transport path 10, and the registration roller 18 whose rotation is stopped skews the sheet S. After correction, the registration rollers 18 feed the sheet S to the image forming device 6 at a predetermined timing. In the image forming device 6, the charging device 12 charges the photosensitive drum 11 to a predetermined potential, the exposure device 13 writes a latent image on the photosensitive drum 11, and the developing device 14 develops the latent image using toner. Thus, a toner image is formed, and the transfer roller 15 transfers the toner image onto the sheet S. FIG. Subsequently, the fixing device 7 fuses the toner image while nipping and conveying the sheet S to fix the toner image on the sheet S, and the sheet discharge roller 8 discharges the sheet S to the sheet discharge tray 9 .

Next, the configuration of the developing device 14 will be described. FIG. 3 is a perspective view showing the appearance of the developing device 14. As shown in FIG. 4 is a right side view of the developing device 14. FIG. FIG. 5 is a perspective view showing the right end portion of the developing device 14. As shown in FIG. In FIG. 5, the II section of FIG. 4 is shown.

[Development housing]
The development housing 21 has a box-like shape with the left-right direction as the longitudinal direction. Grips 26 are provided at two locations in the left-right direction of the front portion of the developing housing 21 . The rear portion of the developer housing 21 is provided with an opening 25 through which a portion of the developer roller 32 is exposed.

[Stirring chamber, impeller]
A stirring chamber 22 in which developer is accommodated is provided at the bottom of the developing housing 21 . The stirring chamber 22 is provided with an impeller 33 whose axial direction is the horizontal direction. The impeller 33 is, for example, a paddle. The bottom of the stirring chamber 22 has a cylindrical shape corresponding to the trajectory of the tips of the blades of the impeller 33 .

[Development roller]
A supply roller 34 is provided behind the stirring chamber 22 . A developing roller 32 is provided behind and obliquely above the supply roller 34 . A portion of the outer peripheral surface of developing roller 32 is exposed through opening 25 . The developing roller 32 includes a sleeve and a permanent magnet provided inside the sleeve (not shown). A gear train 35 is provided at the left end of the developing housing 21 . A driving force generated by a motor (not shown) is transmitted to the developing roller 32 , the impeller 33 , and the supply roller 34 via the gear train 35 .

[Filling port]
A filling port 23 is provided at the right end of the stirring chamber 22 (an example of one end of the stirring chamber 22 in the axial direction of the impeller 33). The filling port 23 has a cylindrical shape that opens to the right.

[Support part]
A support portion 24 that supports the shaft of the impeller 33 is provided inside the filling port 23 . The support portion 24 includes bearings and struts. Three struts are provided radially from the bearing at 120° intervals to connect the bearing and the inner surface of the stirring chamber 22 .

The developer includes, for example, a magnetic carrier and toner in which a coloring material is adhered to resin. The impeller 33 agitates the developer to triboelectrically charge the carrier. The supply roller 34 supplies developer to the development roller 32 . A magnetic brush is formed by the developer on the outer peripheral surface of the developing roller 32 . The latent image is developed by the toner contained in the magnetic brush being attracted to the latent image on the photosensitive drum 11 .

Next, the configuration of the regulating blade 40 and its surroundings will be described. FIG. 7 is a perspective view showing the internal configuration of the developing device 14. As shown in FIG. FIG. 7 shows a cross section of the developing roller 32 on the left end side. 8 and 9 are sectional views of the developing device 14 in the pressed state. 10 and 11 are sectional views of the developing device 14 in the released state. 8 and 10 show cross sections at the position of the developing roller projecting portion 32T adjacent to the left end portion of the developing roller 32. FIG. 9 and 11 show cross sections at the same positions as in FIG. The released state and the pressed state will be described later. In the following, the configuration of the left end portion of the developing device 14 will be described, but the configuration of the right end portion of the developing device 14 is left-right reversed, so the description thereof will be omitted.

The developing device 14 includes an agitating chamber 22 containing developer, an impeller 33 for agitating the developer contained in the agitating chamber 22, a developing roller 32 for holding the developer agitated by the impeller 33, A filling port 23 axially opened at one end of the stirring chamber 22 in the axial direction of the impeller 33; a regulating blade 40 facing the developing roller 32, a biasing member 46 pressing the regulating blade 40 against the developing roller 32, and a release state in which the regulating blade 40 is released from being pressed against the developing roller 32 against the biasing member 46; A switching member 50 that is switched to a pressing state in which the regulation blade 40 is pressed against the developing roller 32 by not resisting the biasing member 46, and a first fitting portion 61 in which the switching member 50 is fitted in the released state. Prepare.

[Regulation blade, biasing member]
The regulating blade 40 is a substantially rectangular plate-like member whose longitudinal direction is the left-right direction. The regulating blade 40 is provided diagonally above and forward of the developing roller 32 in a posture in which the front-rear direction is the normal direction. A lower end portion of the regulating blade 40 is curved in a direction opposite to the outer peripheral surface of the developing roller 32 . The regulating blade 40 is attached to a holder 41 located in front of the regulating blade 40 . The holder 41 is a plate-shaped member having a width slightly wider than that of the regulating blade 40 in the left-right direction. The lower end of the holder 41 is located above the lower end of the regulating blade 40 . A holder hole 41H penetrating in the front-rear direction is provided in the upper portion of the holder 41 and the regulating blade 40 .

The developer housing 21 is provided with a holder guide portion 42 and a spring stopper portion 43 . The holder guide portion 42 has a cylindrical shape whose longitudinal direction is the front-rear direction. The outer diameter of the holder guide portion 42 is substantially equal to that of the holder hole portion 41H. A biasing member 46 is provided in the holder guide portion 42 . The biasing member 46 is, for example, a compression coil spring provided along the outer peripheral surface of the holder guide portion 42 . A spring stop portion 43 having a radial dimension larger than that of the biasing member 46 is provided at the front end portion of the holder guide portion 42 . The spring stop portion 43 restricts forward movement of the biasing member 46 . Note that the biasing member 46 may be a leaf spring or the like.

The holder 41 is arranged behind the biasing member 46, and the holder guide portion 42 is inserted into the holder hole portion 41H. A female thread 44 is formed on the inner surface of the holder guide portion 42 . A male screw 45 is screwed into the female screw 44 . The diameter of the head of the male screw 45 is larger than that of the holder guide portion 42 . The head of the male screw 45 restricts the rearward movement of the holder 41 .

[Switching member]
The switching member 50 faces the rear surface of the left end portion of the holder 41 . The switching member 50 is supported by the developing housing 21 and is rotatable about an axis extending in the left-right direction. The switching member 50 includes a central portion 50C coupled to the developing housing 21, a first projecting portion 51, a second projecting portion 52, and a third projecting portion 53 projecting in different radial directions from the center portion 50C. Prepare. The posture of the switching member 50 shown in FIGS. 7, 10, and 11, that is, the state in which the switching member 50 resists the biasing member 46 and releases the pressing of the regulating blade 40 from the developing roller 32 is called the released state. On the other hand, the posture shown in FIGS. 8 and 9, that is, the state in which the switching member 50 does not resist the biasing member 46 so that the regulating blade 40 is pressed against the developing roller 32 is called the pressing state.

In the pressed state, the surface of the developing roller 32 is slightly recessed by the pressing of the regulating blade 40 . In other words, the regulating blade 40 bites into the developing roller 32 in the pressed state. On the other hand, in the released state, the regulating blade 40 contacts the developing roller 32, but is not pressed against the developing roller 32, so that the surface of the developing roller 32 is not recessed. In other words, the regulating blade 40 does not bite into the developing roller 32 in the released state.

The mutual positional relationship and shape of the first projecting portion 51, the second projecting portion 52, and the third projecting portion 53 will be described with reference to FIG. A first projecting portion 51, a second projecting portion 52, and a third projecting portion 53 are arranged in the clockwise direction when viewed from the right side. When the first projecting portion 51 is positioned horizontally in front of the center portion 50C, the second projecting portion 52 is positioned behind the center portion 50C, and the third projecting portion 53 is positioned slightly behind the center portion 50C. are doing. The first projecting portion 51 and the third projecting portion 53 are formed in a bar shape. The second protruding portion 52 has a starting point behind the central portion 50C, curves in a counterclockwise direction from the starting point, extends obliquely forward and upward, and a tip extends upward.

[First fitting part, second fitting part]
The developing housing 21 is provided with a first fitting portion 61 and a second fitting portion 62 with which the second projecting portion 52 of the switching member 50 is fitted. Specifically, on the inner surface of the left end portion of the developing housing 21, a protruding portion 21B protruding rightward from above to behind the switching member 50 is provided. A first fitting portion 61 into which the second projecting portion 52 is fitted in the released state and a second fitting portion into which the second projecting portion 52 is fitted in the pressed state are formed on the edge of the protruding portion 21B on the switching member 50 side. A portion 62 and are provided. Both the first fitting portion 61 and the second fitting portion 62 are recesses having a shape corresponding to the tip portion of the second projecting portion 52 . Between the first fitting portion 61 and the second fitting portion 62, there is provided a flat surface on which the tip portion of the second projecting portion 52 slides when the switching member 50 rotates between the released state and the pressed state. A sliding surface 63 is provided.

To switch from the released state (see FIGS. 10 and 11) to the pressed state (see FIGS. 8 and 9), the switching member 50 is rotated counterclockwise. At this time, the second protruding portion 52 comes out of the first fitting portion 61 , slides along the sliding surface 63 , and fits into the second fitting portion 62 . On the other hand, to switch from the pressed state to the released state, the switching member 50 is rotated clockwise. At this time, the second protruding portion 52 slides out of the second fitting portion 62 and slides along the sliding surface 63 to fit into the first fitting portion 61 . In other words, the second projecting portion 52 has flexibility, so that the state in which it is fitted in the first fitting portion 61 or the second fitting portion 62 and the state in which it is fitted in the first fitting portion 61 and the second fitting portion 61 can be adjusted. The shape changes to the state where it is not fitted to the portion 62 .

The switching member 50 can be manually rotated. In this embodiment, the rotation from the pressed state to the released state is performed manually. On the other hand, the rotation from the released state to the pressed state is performed by the developing roller projecting portion 32T described below.

[developing roller protrusion]
At the left end of the shaft of the developing roller 32, a rod-shaped developing roller projecting portion 32T projecting in the radial direction is provided. L1 is the distance from the center of the axis of the developing roller 32 to the tip of the developing roller protrusion 32T, L2 is the distance from the center of the axis of the switching member 50 to the tip of the third protrusion 53, and L2 is the axis of the developing roller 32. Assuming that the distance from the center to the center of the axis of the switching member 50 is L3, the sum of L1 and L2 is greater than L3. Therefore, in the released state (see FIGS. 10 and 11), the tip of the first protrusion 51 is located inside the locus 32L of the tip of the developing roller protrusion 32T. When the developing roller 32 starts to rotate clockwise, the developing roller protrusion 32T pushes the third protrusion 53 rearward, so that the switching member 50 is rotated counterclockwise, and the tip of the second protrusion 52 portion slides along the sliding surface 63 after coming out of the first fitting portion 61 and fits into the second fitting portion 62 . By this operation, the posture of the switching member 50 is fixed in the pressed state.

In the pressed state, the tip of the first protrusion 51 and the tip of the third protrusion 53 are positioned outside the locus 32L of the tip of the developing roller protrusion 32T (see FIGS. 8 and 9). Therefore, in the pressing state, the first protrusion 51 and the third protrusion 53 do not contact the developing roller protrusion 32T during the operation of the developing device 14 .

Next, developer filling will be described. The developer is filled when shipping a new developing device 14 and when the developing device 14 is recycled. When the developing device 14 is recycled, it means that the developing device 14 that has run out of toner is collected from the user, filled with developer at a factory, and supplied to the user. The filling of the developer is performed in the following procedure.

First, the operator manually rotates the switching member 50 to switch to the released state (see FIGS. 10 and 11). Then, the pressing of the regulating blade 40 against the developing roller 32 by the first projecting portion 51 is released. Further, since the tip of the second projecting portion 52 fits into the first fitting portion 61, the posture of the switching member 50 is fixed in the released state.

Next, the operator attaches the developing device 14 to the jig 70 with the filling port 23 facing upward. FIG. 6 is a perspective view showing how the developing device 14 is held by the jig 70. As shown in FIG. The jig 70 holds the lower portion (the right end portion in FIG. 3) of the developing device 14 with the filling port 23 facing upward. The vibrator 72 is supported by a frame (not shown) integrated with the jig 70 . The vibrator 72 is in contact with the side surface (bottom portion in FIG. 3) of the developing device 14 .

Next, the operator connects the container 71 containing the developer to the filling port 23 . Next, the operator drops the developer while vibrating the developing device 14 using the vibrator 72 . When a predetermined amount of developer is filled, the operator stops the vibrator 72 , removes the developer container 71 , seals the filling port 23 , and removes the developing device 14 from the jig 70 .

The developing device 14 filled with the developer is shipped from the factory and supplied to the user. When the user attaches the developing device 14 to the printer 1, turns on the power, and inputs a print job, the developing roller 32 and the developing roller projecting portion 32T start rotating clockwise in FIGS. Then, the developing roller projecting portion 32T pushes away the third projecting portion 53, so that the switching member 50 is rotated counterclockwise. This rotation separates the first protrusion 51 from the holder 41 , so that the biasing member 46 moves the holder 41 rearward and presses the regulating blade 40 against the developing roller 32 . In addition, since the tip of the second projecting portion 52 comes out of the first fitting portion 61 and slides along the sliding surface 63 to fit into the second fitting portion 62, the posture of the switching member 50 is pushed. state is fixed.

According to the developing device 14 according to the present embodiment described above, the developing device 14 includes the stirring chamber 22 containing the developer, the impeller 33 for stirring the developer contained in the stirring chamber 22, and the impeller a developing roller 32 holding the developer agitated by the impeller 33; a supporting portion 24 that supports the shaft; a regulating blade 40 that faces the outer peripheral surface of the developing roller 32; an urging member 46 that presses the regulating blade 40 against the developing roller 32; a switching member 50 that switches between a release state in which the pressing of the regulation blade 40 against the developing roller 32 is released and a pressing state in which the regulation blade 40 is pressed against the developing roller 32 by not resisting the biasing member 46; and a first fitting portion 61 to which the member 50 is fitted. According to this configuration, it is possible to release the pressing of the regulating blade 40 with a simple configuration. Moreover, it is possible to prevent the switching member 50 from returning to the pressed state from the released state due to vibration or the like.

Further, according to the developing device 14 according to the present embodiment, the switching member 50 includes the central portion 50C rotatably supported by the shaft parallel to the developing roller 32, and the central portion 50C protruding in different radial directions from the central portion 50C. In the release state, the first protrusion 51 resists the biasing member 46 and pushes back the regulating blade 40 to push the regulating blade 40 toward the developing roller 32. The pressing is released, and the second projecting portion 52 fits into the first fitting portion 61 . According to this configuration, since the switching member 50 is fixed in the released state only by rotating the switching member 50, the pressing of the regulating blade 40 can be released with a simple configuration.

Further, according to the developing device 14 of the present embodiment, the second fitting portion 62 with which the second projecting portion 52 is fitted in the pressed state is provided. According to this configuration, since the switching member 50 is fixed in the pressed state only by rotating the switching member 50, the regulating blade 40 can be pressed with a simple configuration. Also, it is possible to prevent the first projecting portion 51 from coming into contact with the regulation blade 40 due to vibration or the like.

Further, according to the developing device 14 according to the present embodiment, the second projecting portion 52 has flexibility, so that the state in which it is fitted in the first fitting portion 61 or the second fitting portion 62 and the state in which it is fitted to the first fitting portion 62 are shown. The shape changes to the state where it is not fitted to the fitting portion 61 and the second fitting portion 62 . According to this configuration, the switching member 50 can be fixed in the released state and the pressed state with a simple operation.

Further, according to the developing device 14 of the present embodiment, in the released state, the first projecting portion 51 contacts the developing roller 32 and pushes back the regulating blade 40 to a position where it does not bite into the developing roller 32 . With this configuration, the stroke of the regulating blade 40 can be minimized, so the development device 14 can be prevented from becoming large.

Further, according to the developing device 14 according to the present embodiment, the switching member 50 includes the third projecting portion 53 projecting toward the axis of the developing roller 32, and the developing roller 32 extends radially from the axis of the developing roller 32. A projecting developing roller projecting portion 32T is provided, and when the developing roller 32 is driven, the developing roller projecting portion 32T pushes away the third projecting portion 53, whereby the switching member 50 is switched from the released state to the pressed state. According to this configuration, the switching member 50 can be switched from the released state to the pressed state without operating the switching member 50 .

Further, according to the developing device 14 of the present embodiment, in the pressed state, the tip of the first projecting portion 51 and the tip of the third projecting portion 53 are located outside the locus 32L of the tip of the developing roller projecting portion 32T. Located in According to this configuration, it is possible to prevent contact between the first projecting portion 51 and the third projecting portion 53 and the developing roller projecting portion 32T during operation of the developing device 14 .

The above embodiment may be modified as follows.

The second fitting portion 62 included in the above embodiment may not be provided. In this case, the posture of the switching member 50 is not fixed in the pressed state.

The third projecting portion 53 and the developing roller projecting portion 32T included in the above embodiment may not be provided. In this case, it is necessary to manually switch the switching member 50 from the released state to the pressed state before mounting the developing device 14 on the printer 1 or before shipping from the factory.

In the embodiment described above, in the released state, the first projecting portion 51 contacts the developing roller 32 and pushes back the regulating blade 40 to a position where it does not bite into the developing roller 32 . may be configured to push back the regulating blade 40 to a position separated from the developing roller 32 .

12 and 13 are cross-sectional views of a developing device 14 according to a modification. 12 shows the released state, and FIG. 13 shows the pressed state. In this example, the switching member 80 is slidable in the front-rear direction. The switching member 80 includes a rectangular parallelepiped body portion 80C, a first projecting portion 81 projecting forward from the body portion 80C, a second projecting portion 82 projecting upward from the body portion 80C, and a projecting portion downward from the body portion 80C. and a third projecting portion 83 . The main body portion 80C is provided with a long hole portion 84 that penetrates in the left-right direction and is elongated in the front-rear direction. The second protruding portion 82 has a starting point on the upper surface of the main body portion 80C, curves counterclockwise from the starting point, and extends diagonally forward and upward.

The development housing 21 is provided with a first fitting portion 91 and a second fitting portion 92 with which the second projecting portion 82 of the switching member 80 is fitted. Specifically, on the inner surface of the left end portion of the developing housing 21, a protruding portion 21B protruding rightward is provided above the switching member 80. As shown in FIG. A first fitting portion 91 into which the second projecting portion 82 is fitted in the released state and a second fitting portion into which the second projecting portion 82 is fitted in the pressed state are formed on the edge portion of the raised portion 21B on the switching member 80 side. A portion 92 and are provided. Both the first fitting portion 91 and the second fitting portion 92 are recesses having a shape corresponding to the tip portion of the second projecting portion 82 . Between the first fitting portion 91 and the second fitting portion 92, there is provided a flat surface on which the tip portion of the second projecting portion 82 slides when the switching member 80 slides between the released state and the pressed state. A sliding surface 93 is provided. The development housing 21 is provided with a prism-shaped boss 94 that is inserted into the elongated hole portion 84 of the switching member 80 .

To switch from the released state (see FIG. 12) to the pressed state (see FIG. 13), the switching member 80 is slid rearward. At this time, the second projecting portion 82 comes out of the first fitting portion 91 , slides along the sliding surface 93 , and fits into the second fitting portion 92 . On the other hand, to switch from the pressed state to the released state, the switching member 80 is slid forward. At this time, the second projecting portion 82 comes out of the second fitting portion 92 and slides along the sliding surface 93 to fit into the first fitting portion 91 . In other words, the second projecting portion 82 has flexibility, so that the first fitting portion 91 and the second fitting portion 92 are fitted together, and the first fitting portion 91 and the second fitting portion 91 are fitted together. The shape changes to the state where it is not fitted to the portion 92 .

The switching member 80 can be slid manually. In this embodiment, the sliding from the pressed state to the released state is performed manually. On the other hand, the slide from the released state to the pressed state is performed by the developing roller projecting portion 32T. When the developing roller 32 starts to rotate clockwise in the released state (see FIG. 12), the developing roller protrusion 32T pushes the third protrusion 83 rearward, so that the switching member 80 is moved rearward and the second The distal end portion of the projecting portion 82 is pulled out of the first fitting portion 91 , slides along the sliding surface 93 , and fits into the second fitting portion 92 . By this operation, the posture of the switching member 80 is fixed in the pressed state (see FIG. 13). This modification can also provide the same effects as the above-described embodiment.

14 Developing device 22 Stirring chamber 23 Filling port 24 Supporting portion 32 Developing roller 32T Developing roller projecting portion 32L Trajectory 33 Impeller 40 Regulating blade 42 Holder guide portion 43 Spring stopper portion 44 Female screw 45 Male screw 46 Biasing member 50 Switching member 51 First Protruding portion 52 Second protruding portion 53 Third protruding portion 61 First fitting portion 62 Second fitting portion

Claims (7)

a stirring chamber containing a developer;
an impeller for stirring the developer contained in the stirring chamber;
a developing roller holding developer agitated by the impeller;
a filling port opened in the axial direction on one end side of the stirring chamber in the axial direction of the impeller;
a support portion that supports the shaft of the impeller inside the filling port;
a regulating blade facing the outer peripheral surface of the developing roller;
a biasing member that presses the regulation blade against the developing roller;
A release state in which the regulating blade is released from being pressed against the developing roller by resisting the urging member, and a pressing state in which the regulating blade is pressed against the developing roller by not resisting the urging member. a switchable switching member;
and a first fitting portion into which the switching member is fitted in the released state. The switching member is
a central portion rotatably supported on an axis parallel to the developing roller;
a first protrusion and a second protrusion that protrude from the central portion in different radial directions;
In the released state, the first projecting portion pushes back the regulating blade against the biasing member to release the pressing of the regulating blade against the developing roller, and the second projecting portion 2. The developing device according to claim 1, wherein the developing device is fitted in the first fitting portion. 3. The developing device according to claim 2, further comprising a second fitting portion into which said second projecting portion fits in said pressed state. The second projecting portion has flexibility, so that it can 4. The developing device according to claim 3, wherein the shape of the developing device changes between a state in which the developing device does not move and a state in which the developing device does not. 5. The apparatus according to any one of claims 2 to 4, wherein in the released state, the first protrusion contacts the developing roller and pushes back the regulating blade to a position where it does not bite into the developing roller. Developing apparatus as described. the switching member includes a third projecting portion projecting toward the shaft side of the developing roller,
The developing roller has a developing roller protrusion that protrudes radially from the axis of the developing roller,
6. The switching member is switched from the released state to the pressed state by pushing away the third projecting portion from the projecting portion of the developing roller when the developing roller is driven. The developing device according to any one of . 7. The method according to claim 6, wherein, in the pressed state, the tip of the first protrusion and the tip of the third protrusion are positioned outside the trajectory of the tip of the developing roller protrusion. developing device.

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