CN200965624Y - Photographic developer box for image forming device - Google Patents

Abstract

A developer cartridge provided in an image forming apparatus, having a developer-side casing including a toner accommodating chamber and a developing chamber; siding. While the thickness regulating blade scrapes excess charged toner off the developer roller, the plate wall prevents the charged toner from returning to the toner receiving cavity. A soft wiper for cleaning the toner detection window is attached to the agitator for agitating the toner in the toner containing chamber by the fixing member. The fixing member includes a support plate and a gripping plate placed opposite to each other with a gap formed therebetween. When the protrusion protruding from the restricting plate is inserted into the opening formed in the wiper, the wiper is inserted into the slit and fixed to the fixing member.

Description

Developer cartridge for image forming apparatus

Cross References to Related Applications

This application claims Japanese Patent Application 2005-128502 filed April 26, 2005, Japanese Patent Application 2005-138729 filed May 11, 2005, Japanese Patent Application 2005-140893 filed May 13, 2005 and 2005 Japanese Patent Application No. 2005-164321 filed on June 3 is claimed as priority, the contents of which are hereby incorporated by reference into the present application.

Technical field

The present invention generally relates to an image forming device, such as a laser printer, and more particularly, to a developer cartridge and a process cartridge mounted on the image forming device.

Background technique

A conventional electrophotographic image forming device, such as a laser printer using a non-magnetic, one-component developing method, generally includes a photosensitive drum on which an electrostatic latent image is formed, and is used for tribocharging and supplying toner to the photosensitive drum, so that A developer cartridge that forms an electrostatic latent image on a drum.

Such a developer cartridge disclosed in Japanese Patent Application No. 2000-275948 includes a toner accommodating chamber for accommodating toner, a developing chamber for accommodating a supply roller, a developing roller and a thickness regulating blade. The partition wall, in which an opening is formed, divides the developer cartridge into a toner containing chamber and a developing chamber.

This type of developer cartridge also includes an agitator provided in the toner containing chamber for agitating the toner therein. The toner agitated by the agitator is discharged to the developing chamber through the opening formed in the partition wall. When the toner is frictionally charged between the two rollers, the supply roller supplies the discharged toner to the developing roller. The thickness regulation blade scrapes off excess charged toner that is transferred on the developer roller, thereby carrying a thin layer of developer on the surface of the developer roller.

The developing device disclosed in Japanese Patent Application Publication No. 2000-250296 includes transparent windows provided on opposite sides of the toner containing chamber for detecting remaining toner. A cleaning member is further provided on the agitator for cleaning the window.

The developer cartridge disclosed in Japanese Patent Application No. 2005-24811 supports the shaft of the agitator with a support portion having a hollow groove portion having a guiding portion and a deepest portion and a restricting portion. When the agitator is installed, the shaft of the agitator is guided down to the deepest part along the guide of the hollow groove, passes through the restricted part, and is maintained at the deepest part by the restricted part.

The conventional developer cartridges described above have various disadvantages. One disadvantage is that excess charged toner scraped by the thickness regulating blade from the surface of the developer roller is contained in the developer chamber and sometimes returns to the toner containment chamber. As the ratio of pre-charged toner to uncharged toner increases, charging control becomes difficult when friction charging the toner between the supply roller and the developing roller, resulting in reduced image quality. Therefore, it is desirable to supply toner that has been previously charged for development as much and as quickly as possible.

Another disadvantage is the increased number of components required to secure the cleaning member to the mixer, making the installation process more complex. Further, when the cleaning member is fixed by the double-sided belt, it is difficult to peel the cleaning member from the agitator for recycling.

With the above structure for supporting the agitator shaft, when sliding over the restricting portion, there is a danger that the shaft may be broken since a large load is loaded when the shaft deflects.

Another disadvantage is that by forming an opening on the housing of the above-mentioned developer cartridge for exposing the developing roller, the peripheral edge of the opening must be weak. Therefore, when the user clamps the housing near the opening when installing or removing the developer cartridge, the housing deforms (flexes), which may cause damage to the developer roller or force toner to form between the developer roller and the housing. out of the gap.

Contents of utility model

In view of the foregoing, an object of the present invention is to provide a developer cartridge capable of preventing degradation of image quality.

Another object of the present invention is to provide a developer cartridge having a cleaning member fixed to the stirring member by a simple structure.

Still another object of the present invention is to provide a developer cartridge that reduces the risk of damage to the agitator shaft when the agitator is installed in the developer cartridge.

Another object of the present invention is to provide a housing that is reinforced along its upper opening and reliably maintains a precise clearance between the developing roller and the opening edge.

Another object of the present invention is to provide a process cartridge and an image forming apparatus mounted with a developer cartridge achieving at least one of the above objects.

The above and others are achieved by a developer cartridge comprising:

a developer accommodating chamber for accommodating developer;

a developer carrying member carrying a developer;

a supply member that charges and supplies the developer contained in the developer accommodating chamber to the developer carrying member;

a thickness regulating member in pressure contact with the developer carrying member at the contact portion to adjust the thickness of the toner carried on the developer carrying member;

a wall having a bottom end and a top end and arranged between the developer accommodating chamber and the thickness regulating member, the top end of the wall being positioned closer to the supply member than the bottom end of the wall, the wall accommodating the thickness regulating member from the developer The cavities are spaced such that a distance between the supply member and the top end of the wall is shorter than a distance between the supply member and a contact portion where the thickness regulating member contacts the developer carrying member.

With such a structure, the wall provided between the developer accommodating chamber and the thickness regulating member partitions the thickness regulating member from the developer accommodating chamber. The wall is arranged such that the distance between the supply member and the top end of the wall is shorter than the distance between the supply member and a contact portion where the thickness regulating member contacts the developer carrying member. Therefore, when the thickness regulating member scrapes off excess developer from the developer carrying member to regulate the thickness of development carried on the developer carrying member, the developer remaining between the thickness regulating member and the wall can be supplied again to the developer carrying member, and is regulated by pressing contact of the thickness regulating member. As a result, since the developer scraped off by the thickness regulating member, ie, electrostatically charged developer, can be prevented from returning to the developer accommodating chamber, it becomes possible to reliably control developer charging in order to prevent degradation of image quality.

The utility model can reliably tribocharge the developer. Further, the supply member can easily return the pre-charged developer to the developer carrying member, and also easily supply the uncharged developer contained in the developer accommodating chamber to the developer carrying member.

Another aspect of the utility model provides a developer cartridge, which includes:

a developer accommodating chamber for accommodating developer;

at least one window for detecting the amount of developer remaining in the developer containing chamber;

cleaning means for cleaning the window;

an agitating member that agitates the developer accommodated in the developer accommodating chamber; and

A fixing member arranged on the stirring member and having a slit formed therein fixes the cleaning member when the cleaning member is inserted into the slit.

With such a structure, by inserting the cleaning member from the slit of the fixing member, the cleaning member is fixed to the stirring member through the fixing member. This structure eliminates the need for additional parts for fixing the cleaning member and the stirring member, so that the cleaning member can be fixed to the stirring member through a simple installation process. Therefore, the present invention reduces the number of parts required and improves the efficiency of the mounting operation. Furthermore, since the cleaning member is fixed to the fixing member by being inserted from the slit, the cleaning member can also be easily removed, improving the suitability of recycling of the cleaning member.

Another aspect of the utility model provides a developer cartridge, which includes:

a developer accommodating chamber for accommodating developer;

an agitator having an agitator shaft and disposed inside the developer containing chamber; and

a shaft support unit supporting at least one end of the agitator shaft, the shaft support unit comprising:

a holding part agitator shaft which is formed as a groove in the inner wall of the developer accommodating chamber and rotatably holds the agitator shaft;

a guide slot that is open at one end and guides the agitator shaft towards the holding portion; and

A restricting portion that restricts the movement limit of the agitator shaft held in the holding portion between the guide groove and the holding portion, the guide groove being narrower than the holding portion in the inside of the developer accommodating chamber from a concave direction with respect to the holding portion The position directs the agitator shaft towards the restriction.

Since the guide groove guides the agitator shaft toward the restricting portion from a position narrower than the supporting portion in the concave direction in the inner wall, when installing the agitator shaft in the developer cartridge, the agitator shaft is required to slide from the guide groove through the restricting portion. Less deflection reduces the load applied to the agitator shaft and reduces the risk of the agitator shaft being damaged. Furthermore, since the resistance against sliding of the agitator shaft from the guide groove through the restricting portion is small, the agitator shaft can be easily installed.

According to another aspect of the present utility model, a developer cartridge is provided, comprising:

a developer carrying member having a peripheral surface and carrying a developer thereon;

a housing having an opening formed therein and supporting a developer carrying member at an exposed position of the opening, the opening having a rim; and

A reinforcing member is formed substantially in a box shape and arranged along the edge of the opening for reinforcing the edge.

The present structure provides the casing having a box-shaped reinforcing portion along the edge of the opening in which the developer carrying member is exposed, thereby effectively reinforcing the edge of the opening, which portion of the casing is low in strength. Further, since the reinforcing portion is formed into a box shape, the thickness of the housing provided with the reinforcing portion can be equal to the thickness of the area other than the reinforcing portion of the housing, reducing depressions on the surface opposite to the developer carrying member during molding. Possibility of (sinks). Therefore, the opening of the housing can be reliably reinforced while maintaining the precise gap between the developer carrying member and the edge of the opening.

When the user clamps the casing near the opening, the above structure prevents the deformation of the casing, thereby effectively preventing the damage of the developing roller and preventing the developer from leaking from the gap formed between the developing roller and the casing.

Description of drawings

The features, advantages and other objects of the present invention will become apparent when taken in conjunction with the accompanying drawings and the following description, in which:

1 is a side cross-sectional view of a laser printer as an image forming apparatus of the present invention;

2A is a side cross-sectional view of a process cartridge used in the laser printer shown in FIG. 1;

Figure 2B is a side cross-sectional view of a process cartridge usable in the laser printer shown in Figure 1 as an alternative to the process cartridge shown in Figure 2A;

Figure 3 is a rear perspective view of the developer cartridge according to the present invention;

Figure 4 is a rear view of the developer cartridge;

Figure 5 is a side view of the developer cartridge;

Figure 6 is a bottom view of the developer cartridge;

Figure 7 is an enlarged side cross-sectional view of the lower edge of the opening formed in the housing of the developer;

Figure 8 is an enlarged side cross-sectional view of the lower edge of the opening formed in a conventional developer housing;

Figure 9 is an enlarged side cross-sectional view of the lower edge of the opening formed in the housing of Figure 7 according to a variation of the embodiment;

Figure 10 is an enlarged side cross-sectional view of the lower edge of the opening formed in the housing of Figure 7 according to another variation of the embodiment;

11 is a side cross-sectional view of a developing chamber used in the laser printer of FIG. 1;

12 is an enlarged side cross-sectional view showing a portion of the developing chamber near a supply roller, a developing roller, a thickness regulating blade, and a plate wall;

Figure 13 is a cross-sectional view of the developer cartridge in Figure 11 along the line A-A;

Figure 14 is a perspective view from the front of the developer cartridge in Figure 11 when the top cover is opened;

15 is a side cross-sectional view of a developer cartridge used in the laser printer of FIG. 1;

Figure 16 is a perspective view of an agitator in a developer cartridge;

Figure 17 is a top view of the stirrer;

Figure 18 is a cross-sectional view of the portion of the agitator shown by line B-B in Figure 17;

Figure 19 is a cross-sectional view of the portion of the agitator shown by line C-C in Figure 17;

Figure 20 is a perspective view showing the shaft end of the agitator before the wiper is installed;

Fig. 21 is a perspective view showing the shaft end of the agitator after the wiper is installed;

Figure 22 is a top view showing the shaft end of the agitator;

Figure 23 is a bottom view showing the shaft end of the agitator;

24A is a cross-sectional view indicating the process of installing the wiper directly after the wiper is inserted into the gap;

24B is a cross-sectional view indicating the process of installing the wiper when the wiper is further inserted into the gap;

24C is a cross-sectional view illustrating the process of installing the wiper after it has been fully inserted into the gap;

Figure 25A is a top view of a modified wiper according to an embodiment;

Fig. 25B is a cross-sectional view showing the wiper of Fig. 25A being mounted to a fixed member;

26 is a perspective view of a stirrer provided with a guide plate according to a variation of the embodiment;

Fig. 27 is a perspective view showing the agitator shaft held in the shaft supporting unit inside the developer accommodating chamber of the developer cartridge;

Figure 28 is a central cross-sectional view of a developer cartridge without an agitator;

Fig. 29 is a perspective view showing the shaft support unit seen from inside the developer accommodating chamber when the agitator shaft is removed;

Figure 30 is a cross-sectional view of the developer cartridge in Figure 28 taken along the line D-D.

Detailed ways

The general structure of a laser printer will be described. As shown in Figure 1, a laser printer 1 as an image forming device of the present invention includes a main casing 2 and a feed-in unit 4 for supplying paper 3 in the main casing 2, and the paper 3 supplied from the feed-in unit 4 An image forming unit 5 on which an image is formed.

(1) Main housing

The laser printer 1 also includes an access port 6 formed on a side wall of the main casing 2 for inserting and removing a process cartridge 20 described later, and a front cover 7 that can be opened and closed on the access port 6 . The front cover 7 is rotatably supported by a cover shaft 8 inserted through the bottom edge of the front cover 7 . Therefore, when the front cover 7 is rotated closed about the cover shaft 8, the front cover 7 covers the inspection opening 6, as shown in FIG. 1 . When the front cover 7 is rotated open around the cover shaft 8 , the access opening 6 is exposed so that the process cartridge 20 can be installed into or removed from the main casing 2 through the access opening 6 .

In the following description, the side of the laser printer 1 on which the front cover 7 is mounted and the corresponding side of the process cartridge 20 when the process cartridge 20 is mounted into the main casing 2 will be referred to as "front side", and The opposite side will be referred to as the "rear side".

(2) Feed-in unit

The feeding unit 4 includes a paper tray 9 that can be inserted into or removed from the lower part of the main casing 2 in the front-rear direction, a separation roller 10 and a separation pad 11 arranged above the front end of the paper tray 9, and a conveyance with respect to the paper 3. The direction (hereinafter referred to as “sheet conveying direction”) is arranged at the feed roller 12 on the rear side of the separation roller 10 upstream of the separation pad 11 . The feeding unit 4 also includes a paper dust removal roller 13 disposed above and in front of the separation roller 10 and downstream of the separation roller 10 in the paper conveying direction, and a pinch roller 14 disposed opposite to the paper dust removal roller 13 .

The paper transfer path of the paper 3 on the feeding end is reversed toward the rear side of the laser printer 1 , forming a substantially U-shape near the paper dust removal roller 13 . The feed roller 4 also includes a pair of registration rollers 15 disposed below the process cartridge 20 further downstream of the U-shaped portion of the paper conveying path with respect to the paper conveying direction.

A paper platen 16 is provided in the paper tray 9 to support the paper 3 in a stacked state. Platen 16 is pivotally supported at its rear end so that the front end can pivot downward to a resting position, wherein platen 16 rests on the bottom plate of paper tray 9 and can pivot upward to Feed-in position, where the platen 16 slopes upward from the rear end to the front end.

A lever 17 is provided at the front of the paper tray 9 for lifting the front end of the paper platen 16 upward. The rear end of the lever 17 is pivotally supported on the lever shaft 18 at a position below the front end of the platen 16, so that the front end of the lever 17 can be placed at a horizontal position along the bottom plate of the paper tray 9 at the lever 17, and the lever 17 Lifts the platen 16 upwards to pivot between the tilted positions. When a driving force is input to the lever shaft 18, the lever 17 rotates around the lever shaft 18, and the front end of the lever 17 lifts the front end of the platen 16, shifting the platen 16 to the feeding position.

When the platen 16 is in the feed-in position, the topmost sheet of the sheets 3 stacked on the platen 16 is pressed against the feed-in roller 12 . The rotating feed roller 12 starts feeding the sheets of paper 3 between the separation roller 10 and the separation pad 11 .

When the paper tray 9 is removed from the main housing 2, the paper platen 16 settles into a resting position. When the platen 16 is at the parking position, the sheets 3 can be stacked on the platen 16 .

When the feed roller 12 conveys the paper 3 to the separation position, and the paper starts to be inserted between the separation roller 10 and the separation pad 11 , the rotating separation roller 10 separates and feeds the paper 3 one at a time. Each sheet of paper 3 fed by the separation roller 10 passes between the paper dust removal roller 13 and the pinch roller 14 . After the paper dedusting roller 13 removes paper dust from the paper 3 , the paper is conveyed along the U-shaped paper conveying path on the feeding end, reversed direction in the main housing 2 , and conveyed to the registration roller 15 .

After registering the paper 3, the registration roller 15 conveys the paper 3 to a transfer position between the photosensitive drum 28 and a transfer roller 31 described later, where the toner image formed on the photosensitive drum 28 is transferred to the paper 3 on.

(3) Image forming unit

The image forming unit 5 includes a scanning unit 19 , a process cartridge 20 and a fixing unit 21 .

(a) Scanning unit

The scanning unit 19 is arranged on the upper portion of the main housing 2 and includes a laser source (not shown), a polygon mirror 22 that can be driven to rotate, an fθ lens 23 , a mirror 24 , a lens 25 , and a mirror 26 . A laser source emits a laser beam based on image data. As shown by the dotted line in Fig. 1, the laser beam is deflected by the polygon mirror 22, passes through the fθ lens 23, is reflected by the mirror 24, passes through the lens 25, and is reflected downward by the mirror 26 to irradiate the photosensitive material in the process box 20. on the surface of the drum 28 .

(b) Disposal cartridge

As shown in FIG. 2A , the process cartridge 20 is disposed in the main body casing 2 below the scanning unit 19 and can be installed into or removed from the main body casing 2 through the access port 6 . The process cartridge 20 includes a drum cartridge 27 and a developer cartridge 30 detachably mounted on the drum cartridge 27 .

The drum cartridge 27 includes a drum-side casing 76 and, inside the drum-side casing 76 , the photosensitive drum 28 , the scorotron charger 29 , the transfer roller 31 and the cleaning member 32 .

A front drum opening 113 (pre-drum opening) is formed in the drum cartridge 27 for transferring the paper 3 to the transfer position inside the drum cartridge 27, and for transferring the paper 3 backward from the transfer position to the drum cartridge 27 outside rear drum openings 114 (post-drum opening 114). The front drum opening 113 is provided on the front side of the transfer position below the developer cartridge 30 to allow communication in the axial direction of the transfer roller 31 (hereinafter referred to as "axial direction") inside and outside the drum cartridge 27. ). The rear drum opening 114 is formed on the rear side passing through the transfer position opposite to that of the front drum opening 113 to provide communication in the axial direction along the inside and outside of the drum cartridge 27 .

The photosensitive drum 28 includes a main drum body 33 which is cylindrical in shape and has a positively charged photosensitive layer formed of polycarbonate or the like on its outer surface, and passes through it along the axial direction of the main drum body 33 . Centrally extending metal drum shaft 34 . A metal drum shaft 34 is supported within the drum case 27 , and the main drum body 33 is rotatably supported relative to the metal drum shaft 34 . With such a structure, the photosensitive drum 28 is arranged inside the drum cartridge 27 and is rotatable about the metal drum shaft 34 . Further, the photosensitive drum 28 is driven to rotate by a driving force input from a motor (not shown).

The charger 29 is supported on the drum cartridge 27 diagonally at the rear upper portion of the photosensitive drum 28 . The charger 29 is opposed to the photosensitive drum 28, but is separated from the photosensitive drum 28 by a prescribed distance so as not to contact it. The charger 29 includes a discharge wire 35 arranged at an opposite position but separated from the photosensitive drum 28 by a prescribed distance and is located between the discharge wire 35 and the photosensitive drum 28 for controlling the amount of corona discharge from the discharge wire 35 to the photosensitive drum 28 grid 49 . The charger 29 can charge the surface of the photosensitive drum 28 with a uniform positive electrode by applying a high voltage to the discharge line 35 to generate a corona discharge from the discharge line 35 while a bias voltage is applied to the grid 49 .

The developer cartridge 30 includes a casing 36 and, inside the casing 36 , a supply roller 37 , a developing roller 38 , and a thickness regulating blade 39 . The developer cartridge 30 is detachably mounted on the drum cartridge 27 . Therefore, when the process cartridge 20 is installed into the main casing 2, the developer cartridge 30 can be installed by first opening the front cover and then inserting the developer cartridge 30 through the access opening 6 and installing the developer cartridge 30 on the process cartridge 20. main housing 2.

The housing 36 has a box shape opened on the rear side, as will be described later, and has two side walls 69 . A partition wall 40 is provided inside the casing 36 to partition the inside of the casing 36 into a toner containing chamber 41 and a developing chamber 42 . The partition wall 40 is arranged at a halfway position in the front-rear direction inside the case 36 for partitioning the inside of the case 36 in the front-rear direction. An opening 43 is formed midway through the partition wall 40 .

The toner containing chamber 41 occupies the front space of the housing 36 partitioned by the partition wall 40 . The toner containing chamber 41 is filled with non-magnetic, single-component toner having a positive charge. The toner used in the examples is a polymerized toner obtained by polymerizing monomers by a known polymerization method such as suspension polymerization. For example, the polymerizable monomer may be a styrene monomer such as styrene or an acrylic monomer such as acrylic acid, alkyl acrylate or alkyl methacrylate. In order to have good flowability, the polymerized toner is formed into particles that are substantially spherical in shape to obtain high quality of formed images.

This toner is mixed with coloring agents, such as carbon black, or waxes, and additives such as silica to improve flow. The average diameter of the toner particles is about 6-10 microns.

The toner detection windows 44 are provided on both sides 69 of the housing 36 to define the toner containing chamber 41 to detect the amount of toner remaining in the toner containing chamber 41 . The toner detection window 44 is formed on the side wall 69 close to the partition wall 40 and faces across the toner accommodating chamber 41 in the width direction (the direction orthogonal to the front-rear direction and the vertical direction). The toner detection window 44 is formed by embedding a transparent disk-shaped plate on each side wall 69 .

The agitator 45 is disposed in the toner containing chamber 41 to agitate the toner contained therein. The stirrer 45 includes a rotating shaft 46 and a stirring member 47 .

The rotary shaft 46 is rotatably supported in a side wall 69 substantially at the center of the toner containing chamber 41 . The stirring member 47 is provided on the rotation shaft 46 . A motor (not shown) generates a driving force that is input to the rotary shaft 46 to rotate the rotary shaft 46 . Next, the agitating member 47 moves on a circular path around the rotation shaft 46 through the toner accommodating chamber 41 and agitates the toner accommodated in the toner accommodating chamber 41 . When the stirring member 47 stirs the toner, some of the toner is discharged toward the supply roller 37 in the front-rear direction through the opening 43 formed in the partition plate 40 .

The agitator 45 also includes wipers 48 attached to both axial ends of the rotary shaft 46 . When the rotation shaft 46 rotates, the wiper 48 moves in a circular direction around the rotatable shaft 46 through the toner containing chamber 41 to wipe the toner detection window 44 provided on the side wall 69 . Therefore, the wiper 48 is used to clean the toner detection window 44 .

The developing chamber 42 occupies a rear space of the housing partitioned by the partition wall 40 . The developing chamber 42 accommodates the supply roller 37 , the developing roller 38 , and the thickness regulating blade 39 .

The supply roller 37 is arranged behind the opening 43 and includes a metal roller shaft 50 covered by a foam roller 51 formed of an electrically conductive foam material. The roller shaft 50 is rotatably supported in both side walls 69 of the housing 36 inside the developing chamber 42 . The supply roller 37 is driven to rotate by a driving force input to the roller shaft 50 by a motor (not shown).

The developing roller 38 is arranged behind the supply roller 37 and is brought into contact with the supply roller 37 by pressure so that both are compressed. The developing roller 38 includes a metal roller shaft 52 and a rubber roller 53 formed of a conductive rubber material covering the roller shaft 52 . The roller shaft 52 is rotatably supported in both side walls 69 inside the developing chamber 42 . The rubber roller 53 is more specifically formed of conductive urethane foam rubber or silicone rubber containing fine carbon particles, and its surface is covered with urethane foam rubber or fluorine-containing silicone rubber. The developing roller 38 is driven to rotate by a driving force input to the roller shaft 52 by a motor (not shown). Further, a developing bias is applied to the developing roller 38 in a developing operation.

When the developer cartridge 30 is installed in the drum cartridge 27, the developing roller 38 is diagonally opposed to the photosensitive drum 28 from its upper front end. In other words, the rear portion of the developing roller 38 protruding farthest rearwardly downward from the vertical center is in contact with the photosensitive drum 28 .

The thickness regulating piece 39 includes a main blade member 54 composed of a metal leaf spring, a pressure portion 55 provided on a distal end of the main blade member 54 . The pressure portion 55 has a semicircular cross section and is formed of insulating silicone rubber. A thickness regulating piece 39 is attached to the housing 36 . More specifically, a mounting member 109 is provided to secure the bottom end of the main blade member 54 to the rear end of the housing 36 .

A sealing member 110 is inserted between the housing 36 and the mounting member 109 to prevent toner from leaking therebetween.

The mounting member 109 is provided at the rear of the housing 36 and includes a plate-shaped front support member 115 , a rear support member 111 having a substantially L-shaped section, and screws 112 . The front support member 115 is disposed on the rear side of the sealing member 110 . The bottom end of the main blade member 54 is arranged on the rear side of the front support member 115 , and the rear support member 111 is arranged on the rear side of the bottom end of the main blade member 54 . Screws 112 are inserted through the rear support member 111 into the bottom end of the main blade member 54, and the front support member 115, and secure these members together. With the sealing member 110 interposed between the thickness adjusting piece 39 and the case 36 , the thickness regulating piece 39 is fixed to the case 36 together with the mounting member 109 by screws 130 (see FIGS. 3 and 4 ). Thus, the main blade member 54 is attached to the housing 36 by interposing the bottom end of the main blade member 54 between the front support member 115 and the rear support member 111 . With such a structure, the pressure portion 55 arranged at the distal end of the main blade member 54 comes into contact with the developing roller 38 by the elastic force of the main blade member 54 .

The toner discharged through the opening 43 is supplied onto the developing roller 38 by the rotary supply roller 37 . At the same time, the toner is positively frictionally charged between the supply roller 37 and the developing roller 38 . When the developing roller 38 rotates, toner is supplied to the developing roller 38 passing between the rubber roller 53 of the developing roller 38 and the pressure portion 55 of the thickness regulating blade 39 , thereby maintaining a uniform thickness of the toner on the surface of the developing roller 38 .

The cleaning member 32 includes a cleaning brush 58 for scraping off paper dust and the like placed on the photosensitive drum 28 .

As the photosensitive drum 28 rotates, the charger 29 charges the surface of the photosensitive drum 28 with a uniform positive electrode. Next, the laser beam emitted from the scanning unit 19 is scanned at high speed on the surface of the photosensitive drum 28 to form an electrostatic latent image corresponding to the image to be formed on the paper 3 .

Next, when the developing roller 38 rotates, the positively charged toner carried on the surface of the developing roller 38 comes into contact with the photosensitive drum 28, and is supplied to the surface area of the positively charged photosensitive drum 28 exposed by the laser beam, and, Therefore there is a low potential. In this way, the electrostatic latent image on the photosensitive drum 28 is converted into a visible image according to a reverse developing process so that the toner image is carried on the surface of the photosensitive drum 28 .

Next, when the registration roller 15 passes through the front drum opening 113 and passes the paper 3 into the drum cartridge 27 through the transfer position between the photosensitive drum 28 and the transfer roller 31, the The toner image on the surface is transferred onto the paper 3 by a transfer bias applied to the transfer roller 31 . After the toner image is transferred, the paper 3 passes through the rear drum opening 114 and is conveyed out of the drum cartridge 27 , and is conveyed to the fixing unit 21 .

The toner remaining on the photosensitive drum 28 after the transfer operation is recovered by the developing roller 38 . Further, paper dust accumulated on the photosensitive drum 28 from the paper 3 is recovered by the cleaning brush 58 of the cleaning member 32 .

(c) Fixing unit

The fixing unit 21 is arranged on the rear side of the process cartridge 20 and includes a fixed frame 59 ; a heating roller 60 and a pressure roller 61 provided in the fixed frame 59 .

The heating roller 60 includes a metal tube whose surface is coated with a fluororesin, and a halogen lamp placed inside the metal tube for heating. The heat roller 60 is driven to rotate by a driving force input from a motor (not shown).

The pressure roller 61 is placed under and opposed to the heating roller 60 and pressure-contacts the heating roller 60 . The pressure roller 61 is constituted by a metal roller shaft covered with a roller formed of a rubber material. The pressure roller 61 is driven following the rotation of the heating roller 60 .

In the fixing unit 21 , when the paper 3 passes between the heat roller 60 and the pressure roller 61 , the toner image transferred onto the paper 3 at the transfer position is fixed to the paper 3 by heat. After the toner image is fixed to the paper 3 , the heat roller 60 and the pressure roller 61 continue to convey the paper 3 along the discharge end paper conveyance path to the discharge tray 62 formed on the top surface of the main casing 2 .

The paper transfer path at the discharge end leads from the fixing unit 21 to the discharge tray 62 and is substantially U-shaped for reversing the transfer direction of the paper 3 to a direction toward the front of the laser printer 1 . A pair of delivery rollers 63 is arranged at a midpoint along the delivery end sheet delivery path, and a pair of delivery rollers 64 is arranged at the downstream end of the same path.

Therefore, after passing through the fixing unit 21, the paper 3 is conveyed along the discharge end paper conveying path, where the conveying roller 63 receives and conveys the paper 3 to the discharge roller 64, and the discharge roller 64 then receives and discharges the paper 3 to the discharge tray 62 superior.

Next, the structure related to the casing of the developer cartridge will be described.

2A and 3, the housing 36 of the developer cartridge 30 has a box shape, is open on the rear side and is integrally provided with a top wall 70, a front wall 72, the above-mentioned two side walls 69 and a bottom wall. 71. The open area on the rear side is an opening 94 .

As shown in FIG. 3 , the opening 94 is defined by the rear support member 111 of the mounting member 109 , the rear edge of the side wall 69 and the rear edge of the bottom wall 71 . The opening 94 is substantially rectangular when viewed from the rear side and extends in the width direction. The developing roller 38 is disposed in the opening 94 and exposed therefrom. As shown in FIG. 5, the developing roller 38 is supported on the casing 36 so as to protrude from the casing 36 through the opening 94 when viewed from the side. Insertion holes 121 positioned opposite to each other in the width direction are formed in the rear end of each side wall 69 of the housing 36 . The roller shaft 52 of the developing roller 38 is inserted through the insertion hole 121 so that the developing roller 38 is rotatably supported on the casing 36 while the vertical center portion of the rubber roller 53 protrudes farthest from the casing 36 through the opening 94 .

As shown in FIG. 2A , the top wall 70 is plate-shaped in plan view and functions to isolate the top ends of the toner containing chamber 41 and the developing chamber 42 .

The front wall 72 is plate-shaped in front view and functions to isolate the front side of the toner containing chamber 41 . The front wall 72 extends downward from the front edge of the top wall 70 .

As shown in FIGS. 3 and 5 , the side wall 69 is plate-shaped and functions to isolate the sides of the toner containing chamber 41 and the developing chamber 42 . The side wall 69 also rotatably supports the rotary shaft 46 , the roller shaft 50 and the roller shaft 52 .

As shown in FIG. 2A , the bottom wall 71 functions to isolate the bottoms of the toner containing chamber 41 and the developing chamber 42 . The bottom wall 71 is integrally provided with a front bottom wall 74 , a central bottom wall 75 and a rear bottom wall 76 .

The front bottom wall 74 has a substantially semicircular cross section following the rotational path of the agitator 45 in the toner containing chamber 41 . The central bottom wall 75 is provided on the rear side of the front bottom wall 74 and has a substantially semicircular cross-section following the peripheral surface of the supply roller 37 in the developing chamber 42 .

The rear bottom wall 76 is provided on the rear side of the central bottom wall 75 and has a flange plate shape inclined downward to the rear. The rear edge of the rear bottom wall 76 is a lower edge 68 forming a lower edge of an opening 94 extending in the width direction of the housing 36 .

A handle 77 is provided on the front side of the casing 36 for the user to grasp when installing or removing the developer cartridge 30 and the process cartridge 20 . A handle 77 protrudes forward from the top of the front wall 72 constituting the housing 36 .

As shown in FIG. 3 , a gear mechanism (not shown) for driving the rotating shaft 46, the roller shaft 50 and the roller shaft 52 to rotate and a gear cover 79 for covering the gear mechanism are provided between the side walls 69 constituting the housing 36. one up. The two partial rear walls 73 are arranged on the lower edge 68 in the opening 94 of the housing 36 .

Portions of the rear wall 73 are arranged at lateral ends of the lower side 68 and are spaced apart in the width direction. Portions of the rear wall 73 extend upwardly from both lateral ends of the lower side 68 . The bottom of each partial rear wall 73 on the laterally inner side is cut away to form a substantially L-shape in rear view.

The reinforcement 80 is arranged on the lower side 68 of the opening 94 .

The reinforcement 80 extends along the lower edge 68 between the two partial rear walls 73 and is mounted in a cutout of the partial rear walls 73 . The reinforcing portion 80 is formed continuously from the lower side 68 of the opening 94 and is integrally provided with a top wall 82 , a front wall 85 , a bottom wall 83 and two side walls 84 . The reinforcing portion 80 is box-shaped and opened on the rear side. In particular, the cross section of the reinforcing portion 80 taken at right angles to the width direction substantially forms three sides of a rectangle without a rear side.

As shown in FIGS. 3 and 7 , the top wall 82 is disposed along and formed continuously with the lower edge 68 . The top wall 82 protrudes rearward. The front wall 85 is formed substantially as an elongated rectangular plate along the lower side 68 and extends downwardly from the front side of the top wall 82 . The bottom wall 83 also has a substantially elongated rectangular plate shape extending along the lower side and is placed opposite the top wall 82 in the vertical direction. The bottom wall 83 extends obliquely downward and rearward from the lower edge of the front wall 85 .

As shown in FIG. 3 , the side walls 84 have a substantially rectangular plate shape and are arranged at both lateral ends of the top wall 82 , the front wall 85 and the bottom wall 83 so as to face each other in the width direction.

As shown in FIG. 7 , the front wall 85 connects front ends of the front wall 82 and the bottom wall 83 , and the cross section of the reinforcing portion 80 taken at right angles to the width direction forms three sides of a rectangle opened rearward. Further, as shown in FIG. 3 , the two side walls 84 connect the two lateral sides of the top wall 82 to the respective lateral sides of the front wall 85 and the bottom wall 83 , forming a box shape opened rearward.

The portion of the lower side 68 above the reinforcing portion 80 as shown in FIG. 7 is integrally provided with a rear step portion 97 and a front step portion 98 placed diagonally in front of the rear step portion 97 . With such a structure, the cross section of the lower edge 68 taken at right angles to the width direction has a stepped form.

The rear step 97 includes a rear surface 99 and a top surface 100 . The rear surface 99 is formed at the end surface on the rear side of the top wall 82 . The rear surface 99 is a flat vertical surface in a cross section taken at right angles to the width direction. The top surface 100 is provided continuously from the top of the rear surface 99 . In a cross section taken at right angles to the width direction, the top surface 100 has a flat plate shape extending diagonally upward and forward from the rear surface 99 .

The front stepped portion 98 includes a rear surface 101 and a top surface 102 . The rear surface 101 is continuously formed from the front edge of the top surface 100 . In a cross section taken at right angles to the width direction, the rear surface 101 is plate-shaped and extends diagonally upward and rearward from the front edge of the top surface 100 .

The top surface 102 is continuously formed from the top side of the rear surface 101 . In a cross section taken at right angles to the width direction, the top surface 102 has a plate shape extending diagonally upward and forward from the top edge of the rear surface 101 .

A lower sheet 87 (film) is disposed on the top surface 102 of the lower edge 68 . The lower sheet 87 is formed of a polyethylene terephthalate sheet substantially in the shape of a rectangular sheet. As shown in FIGS. 2A and 7 , the rear half of the lower sheet 87 is secured to the surface of the top surface 102 .

In particular, as shown in FIG. 7 , the lower sheet 87 is arranged such that the rear edge of the lower sheet 87 is flush with the rear surface 101 of the lower edge 68 . More particularly, using the rear edge of the top surface 102 (the edge formed by the rear surface 101 and the top surface 102) as a reference for the front-to-back direction, the rear half of the lower sheet 87 is secured with double-sided tape or the like (not shown) to the top surface 102 . As a result, the rear end surface of the lower sheet 87 is positioned flush with the reference in the front-rear direction.

As shown in FIG. 2A , the lower sheet 87 is positioned such that the rear half is fixed to the top surface 102 and the front half extends obliquely upward and forward to contact the lower surface of the developing roller 38 . Thus, the lower sheet 87 blocks the gap between the lower edge 68 and the developing roller 38 and prevents toner from leaking through the gap.

As shown in FIGS. 3 and 6 , a guide member 81 is provided on the housing 36 of the developer cartridge 30 . The guide member 81 protrudes downward from the bottom wall 71 and is plate-shaped, extending in the front-rear direction. The guide members 81 are arranged at intervals in parallel with each other in the width direction. As shown in FIG. 2A , each guide member 81 protrudes downward from the rear bottom wall 76 and the central bottom wall 75 and has a rear end 105 connected to the front wall 85 and the bottom wall 83 , and a front end 104 connected to the front bottom wall 74 . Each guide member 81 is integrally formed with the bottom wall 83 , the front wall 85 , the rear bottom wall 76 , the center bottom wall 75 and the front bottom wall 74 . Each guide member 81 also has a lower edge 106 that extends straight forward from the rear end of the bottom wall 83 and then bends slightly upward and forward below the central bottom wall 75 to contact the rear end of the front bottom wall 74 .

As shown in FIG. 3 , a guide member reinforcing portion 86 is provided to reinforce the guide member 81 . As shown in FIGS. 2A and 6 , the guide member reinforcement portion 86 has a plate shape and extends in the width direction. The guide member reinforcement 86 protrudes downward from the central bottom wall 75 so as to intersect the front-rear midpoint of each guide member 81 in a direction substantially at right angles to the front-rear direction. The guide member reinforcement portion 86 connects the guide member 81 in the width direction and reinforces the guide member 81 .

In the developer cartridge 30 of the above-described embodiment, the box-shaped reinforcing portion 80 opened at the rear is provided along the lower side 68 of the opening 94 . Reinforcement 80 effectively reinforces lower edge 68 of opening 94 , which is a vulnerable area in housing 36 . By forming the box-shaped reinforcing portion 80 opened to the rear side, it is possible to form the outer shell 36 with a uniform thickness in the region of the reinforcing portion 80 and in other regions except the reinforcing portion 80 to reduce the number of parts that are continuously formed with the reinforced portion 80. The possibility of sinks developing during the molding process on the opposite surface of the developer roller 38, that is, the top surface 102 of the lower edge 68. Therefore, the reinforcing portion 80 can reliably reinforce the opening 94 of the casing 36 and, moreover, can maintain a precise gap between the developing roller 38 and the lower edge 68 of the opening 94 .

In the developer cartridge 30 in the above-described embodiment, the cross-section of the reinforcing portion 80 taken at right angles to the width direction is a rectangular shape with three sides, facilitating removal of the reinforcing portion 80 during molding and making The reinforcing portion 80 can be easily formed into a box shape. Therefore, it is possible to reliably reinforce the opening 94 of the housing 36 while simplifying the molding process.

In the developer cartridge 30 in the illustrated embodiment, the reinforcing portion 80 extends in the width direction of the developing roller 38 , that is, along the width direction of the casing 36 in the lower side 68 of the opening 94 . Reinforcing portion 80 prevents deformation of housing 30 when a user grasps housing 36 near opening 94 , thereby effectively preventing damage to developing roller 38 and occurrence of toner leakage between developing roller 38 and housing 36 .

The lower sheet 87 in the developer cartridge 30 in the illustrated embodiment blocks the gap formed between the lower edge 68 of the opening 94 and the developing roller 38, preventing toner from leaking through the gap. Further, the reinforcing portion 80 provided on the lower side 68 is formed in a box shape, so that a depression is less likely to occur on the top surface 102 of the lower side 68 opposite to the developing roller 38 during molding. As a result, the top surface 102 can be formed as a smooth surface, so that the lower sheet 87 can be precisely fixed to the smooth top surface 102 .

When the lower edge 68 is formed into a simple rectangular cross-section, in the conventional structure as shown in FIG. As shown by the line, if the lower edge 68 contacts another component, the lower sheet 87 is susceptible to peeling off from the lower edge 68. On the other hand, if the lower sheet 87 is fixed to a position on the lower edge 68 farther forward than the rear edge, as shown by the dotted line in FIG. Used to secure the lower sheet 87 to a well-defined reference point on the lower edge 68 . As a result, it is impossible to securely fix the lower sheet 87 to the lower side 68 in the width direction, lowering the mounting accuracy of the lower sheet 87 .

However, in the developer cartridge 30 in the illustrated embodiment, the lower side 68 has a stepped cross-sectional shape constituted by the rear stepped portion 97 and the front stepped portion 98 . By aligning the rear edge of the lower sheet 87 with the rear edge of the front stepped portion 98 provided farther forward than the rear stepped portion 97, that is, on the upstream side in the direction in which toner leaks through the opening 94, the lower sheet 87 is fixed. Go to the bottom 68. Therefore, if the rear step portion 97 contacts another member, since the lower sheet 87 is fixed to the front step portion 98 arranged in front of the rear step portion 97 , the lower sheet 87 is less likely to be peeled off from the top surface 102 . Also, fixing the lower sheet 87 on the front stepped portion 98 using the rear edge of the front stepped portion 98 as a reference point enables the lower sheet 87 to be securely fixed along the top surface 102 .

In the developer cartridge 30 in the illustrated embodiment, the developer roller 38 protrudes from the housing 36 through the opening 94 . Therefore, when the developer cartridge 30 is installed on the drum cartridge 27, the developing roller 38 can face the photosensitive drum 28 from the position of the top front side so that a part of the developing roller 38 passes through the opening below the vertical center protruding farthest. 94 contacts the photosensitive drum 28 . This structure can increase the degree of freedom in setting the layout of the device, enabling production of a more compact device. This configuration can also allocate space for forming the reinforcement 80 on the lower side 68 .

In the developer cartridge 30 in the illustrated embodiment, when the paper 3 is conveyed into the drum cartridge 27 through the front drum opening 113, the guide member 81 is continuously formed with the reinforcing portion 80 to guide the paper 3 to the photosensitive drum 28 and The transfer position between the transfer rollers 31. Therefore, the guide member 81 can smoothly guide the sheet 3 to the transfer position, and further reinforce the opening 94 of the housing 36 .

Further, the guide member 81 is formed along the front-rear direction at right angles to the direction in which the reinforcing portion 80 extends. The guide members 81 are spaced at intervals in the width direction. Therefore, the guide member 81 can reliably guide the paper 3 to the transfer position and reduce the frictional resistance generated between the paper 3 and the guide member 81 .

The process cartridge 20 and the laser printer 1 of the above-described embodiment include the developer cartridge 30 provided with the reinforcing portion 80 for reinforcing the opening 94 formed in the housing 36 . Therefore, the developer cartridge 30 increases the rigidity of the process cartridge 20 and the laser printer 1 .

In the above-described example, the developer cartridge 30 is detachably mounted on the drum cartridge 27 to form the process cartridge 20 , and the process cartridge 20 is detachably mounted in the main casing 2 . However, it is also possible to provide the photosensitive drum 28, the charger 29, the transfer roller 31, the cleaning member 32, and the like in the main casing 2, remove the drum cartridge 27, and detachably mount the developing unit in the main casing 2. Kit of 30.

In the above-described embodiment, the cross-section of the reinforcing portion 80 taken at right angles to the width direction forms three sides of a rectangle opened rearward, as shown in FIG. 7 . However, the reinforcing part of the present invention does not need to have this cross-sectional shape if the reinforcing part has a box shape. For example, the rear edges of top wall 82, bottom wall 83, and side walls 84 (not shown in FIG. 9) may be connected by rear wall 95, as shown in FIG. With this structure, the cross-section of the reinforcing portion taken at right angles to the width direction is a closed, hollow rectangle.

Alternatively, as shown in FIG. 10, the reinforcing portion 80 may be formed by connecting the front edges of the top wall 82 and the bottom wall 83 so that the cross section of the reinforcing portion obtained at right angles to the width direction forms a V-shape open rearward. .

As shown in FIG. 1 , the developer cartridge 30 is detachably installed in the drum side housing 76 . Therefore, when the process cartridge 20 is mounted in the main casing 2, the developer cartridge 30 can be installed in the main housing 2.

As shown in FIG. 11 , the developer cartridge 30 includes a developer side casing 36 and, in the developer side casing 36 , a developing roller 38 , a supply roller 37 , a thickness regulating blade 39 and a plate wall 49 .

As shown in FIGS. 11 and 14 , the developer side housing 36 is formed in a box shape with the rear side open. The developer side casing 36 includes a top cover 70 and a main casing 87 . The opening formed on the rear side is a rear opening 94 .

The rear opening 94 is defined by a rear support member 111 of a later-described mounting member 109 and rear edges of the side walls 69 and the bottom wall 71 . The rear opening 94 is substantially rectangular in rear view and extends in the width direction (hereinafter, the width direction will mean a direction at right angles to the front-rear direction and the vertical direction).

The top cover is plate-shaped in plan view, and opens and closes above a toner containing chamber 41 and a developing chamber 42 described later. The top cover 70 is formed integrally with the upper part of the partition wall 40 described later, the plate wall 49 , and a plurality of front and rear ribs 88 and lateral ribs 89 described later.

The front and rear ribs 88 are plate-shaped and parallel to each other, and extend in the front-rear direction on the top cover 70 when the top cover 70 is assembled on the main housing 87 (see FIG. 11 ). As shown in FIG. 14, the front and rear ribs 88 are arranged in parallel to each other at intervals in the width direction on the lower surface of the top cover 70 opposite to the inside of the developer side casing 36. As shown in FIG. The forward protrusion 90 is placed at the front end of two of the front and rear ribs 88 disposed closest to the lateral center of the top cover 70 to approach the front edge of the top cover 70 .

Two of the front and rear ribs 88 closest to the lateral ends of the top cover 70 are also provided with a stepped portion 91 in the middle in the front-back direction. A rearward protruding portion 93 near the rear edge of the top cover 70 is provided on the rear end of these stepped portions 91 to form a narrow stepped structure along the front-rear direction. Further, lateral protrusions 100 are formed on the front and rear ribs 88 closest to the lateral sides of the top cover 70 protruding outward from the narrow stepped structure width direction.

The transverse ribs 89 are plate-shaped and parallel to each other, extending in the width direction on the top cover 70 when the top cover 70 is assembled on the main housing 87 (see FIG. 11 ). As shown in FIG. 14 , parallel transverse ribs 89 are arranged at intervals in the front-rear direction on the lower surface of the top cover 70 facing the inside of the developer-side casing 36 so that the front-rear ribs 88 intersect.

The main housing 87 is integrally provided with the front wall 72 , the two side walls 69 , the bottom wall 71 and the blade mounting portion 73 . A top opening 95 covered by the top cover 70 is formed at the top of the main case 87 .

The front wall 72 is plate-shaped in front view and functions to isolate the front side of the toner containing chamber 41 . As shown in FIG. 11 , the front wall 72 extends downwardly from the front edge of the top cover 70 .

The side wall 69 is plate-shaped and functions to isolate the sides of the toner containing chamber 41 and the developing chamber 42 . The side wall 69 also rotatably supports the agitator rotation shaft 46 , the supply roller shaft 50 , and the developing roller shaft 52 described later.

The bottom wall 71 functions to isolate the bottoms of the toner containing chamber 41 and the developing chamber 42 . The bottom wall 71 is integrally provided with a front bottom wall 77 , a center bottom wall 78 and a rear bottom wall 79 .

The front bottom wall 77 has a substantially semicircular cross-section following the rotation path of an agitator 45 described later in the toner containing chamber 41 .

The central bottom wall 78 is provided on the rear side of the front bottom wall 77 and has a substantially semicircular cross-section following the peripheral surface of the supply roller 37 in the developing chamber 42 .

The rear bottom wall 79 is provided at the rear side of the front bottom wall 77 and has a flange plate shape inclined rearward and downward.

The blade mounting portion 73 extends in the width direction across between upper rear edges of the side walls 69 . The blade mounting portion 73 has a triangular cross-section that narrows toward the bottom. The rear surface of the blade mounting portion 73 is inclined downward and forward.

When viewed from the top, the top opening 95 is similar in shape to the outer sides of the lattice formed by the intersecting front and rear ribs 88 and transverse ribs 89 on the roof 70 to fit on these outer sides. Step portions 96 are formed on both side walls 69 constituting the sides of the top opening 95 for loosely fitting the top cover 70 closest to the outer lateral sides of the top cover 70 when the top cover 70 is assembled on the main case 87. The stepped portions 91 of the two front and rear ribs 88 .

As shown in Figures 11 and 14, the hook portion formed by the rear edge of the top cover 70 and each rearward protrusion 93 can be engaged with the edge of the blade mounting portion 73 at a lateral end formed by the top surface of the blade mounting portion 73 and The front surface is formed and has an L-shaped cross-section to position the rear edge of the top cover 70 relative to the rear edge of the main housing 87 when assembled. The top cover 70 is then rotated in the direction of the arrow in FIG. Formed in the top opening 95, thereby completing the assembly process of the top cover 70 on the main housing 87.

By placing the rearward projection 93 in contact with the blade mount 73 during this assembly, the top cover 70 can be positioned relative to the main housing 87 on the rear edge. Further, when the lateral projections 100 provided on the outermost front and rear ribs 88 in the width direction contact the inner surfaces of the side walls 69 constituting the main housing 87, the top cover 70 can be positioned relative to the main housing in the width direction. 87 were located. The forward projections 90 provided on the two centrally located front and rear ribs 88 then contact the inner surface of the front wall 72 constituting the main housing 87 to position the top cover 70 relative to the main housing 87 on the front side. As a result, the top cover 70 can be fitted on the main case 87 without movement therebetween.

A handle 80 is provided on the front side of the developer side casing 36 for the user to grip when installing or removing the developer cartridge 30 and the process cartridge 20 . A handle 80 protrudes forward from the top of the front wall 72 constituting the developer side housing 36 .

A gear mechanism 81 for driving the rotation of the agitator rotation shaft 46 , the supply roller shaft 50 , and the developing roller shaft 52 and a gear cover 82 for covering the gear mechanism 81 are provided on one of the side walls 69 constituting the developer side housing 36 .

A partition wall 40 is provided in the developer side casing 36 for partitioning the inside of the developer side casing 36 into a toner containing chamber 41 and a developing chamber 42 .

A partition wall 40 is arranged at a middle position in the front-rear direction inside the developer-side casing 36 for partitioning the inside of the developer-side casing 36 in the front-rear direction. An opening 43 penetrates a middle area of the partition wall 40 to allow communication between the toner containing chamber 41 and the developing chamber 42 . A lower portion of the partition wall 40 is formed from a connecting portion of the front bottom wall 77 and the center bottom wall 78 . An upper portion of the partition wall 40 is formed on the top cover 70 in a width direction to be vertically opposed to a lower portion of the partition wall 40 with an opening 43 formed therebetween. The partition wall 40 vertically extends downward from the top cover 70 , and the bottom end of the partition wall 40 is connected to the top cover 70 at substantially the same position as the stepped portion 91 in the front-rear direction of the top cover 70 .

As shown in FIG. 11 , the toner containing chamber occupies a space on the front side of the housing 36 partitioned by the partition wall 40 . The toner containing chamber 41 is filled with non-magnetic, single-component toner having a positive charge.

Toner supply openings for filling the toner containing chamber 41 with toner are formed in both side walls 69 of the developer side housing 36 defining the toner containing chamber 41 . The toner supply opening is sealed with a cap 35.

Toner detection windows 44 are provided in both side walls 69 of the housing 36 defining the toner containing chamber 41 for detecting the amount of toner remaining in the toner containing chamber 41 . The toner detection windows 44 are formed in the side wall 69 close to the partition wall 40 and through the toner containing chamber 41 and face each other in the width direction. The toner detection window 44 is formed by embedding a transparent disc-shaped plate in each side wall 69 .

An agitator 45 is disposed in the toner containing chamber 41 for agitating the toner contained therein. The stirrer 45 includes a rotating shaft 46 and a stirring member 47 . The rotation shaft 46 is rotatably supported in the side wall 69 substantially at the center of the toner containing chamber 41 . The stirring member 47 is provided on the rotation shaft 46 . A motor (not shown) generates driving force, and the input rotary shaft 46 is used to drive the rotary shaft 46 to rotate.

The agitator 45 also includes wipers 48 attached to both shaft ends of the rotary shaft 46 . When the rotation shaft 46 rotates, the wiper 48 moves in a circular direction around the rotation shaft 46 through the toner receiving chamber 41 to wipe the toner detection window 44 provided in the side wall 69 . Therefore, the wiper 48 functions to clean the toner detection window 44 .

The developing chamber 42 occupies a rear-side internal space of the casing 36 partitioned by the partition wall 40 . The developing chamber 42 accommodates the supply roller 37 , the developing roller 38 and the thickness regulating blade 39 and is provided with a plate wall 49 .

The supply roller 37 is arranged behind the opening 43 above the central bottom wall 78 of the developing chamber 42 . The supply roller 37 is diagonally opposed to the developing roller 38 from the lower front side so that the top of the supply roller 37 is lower than the top edge of the lower part of the partition wall 40 .

The supply roller 37 includes a metal roller shaft 50 covered with a sponge roller 51 formed of a conductive foam material. The supply roller 37 is supported in the side wall 69 of the developer side housing 36 and is in contact with the developing roller 38 so that both are compressed to some extent. In particular, the positions of the through holes 122 opposite to each other in the width direction are provided in each side wall 69 . The supply roller shaft 50 is inserted into the through hole 122 so that the supply roller 37 is rotatably supported in the developer side housing 36 .

Driving force from a motor (not shown) is input to the supply roller shaft 50 to drive the supply roller 37 in rotation. The supply roller 37 rotates counterclockwise in FIG. 11 so that the outer peripheral surface of the supply roller 37 moves in the opposite direction of the developing roller 38 at the point of contact between the two rollers.

The developing roller 38 is arranged above the rear bottom wall 79 of the developing chamber 42 on the side opposite to the supply roller 37 of the toner containing chamber 41 in the front-rear direction, that is, behind the supply roller 37 . The developing roller 38 is diagonally opposed to the supply roller 37 from the upper rear side and is in pressure contact with the supply roller 37 .

The developing roller 38 is arranged such that substantially the upper half of the developing roller 38 is above the top of the supply roller 37 . The developing roller 38 has a larger diameter than the supply roller 37 and includes the above-mentioned metallic developing roller shaft 52 , and a rubber roller 53 formed of a conductive rubber material covering the developing roller shaft 52 . The rubber roller 53 is more specifically formed of conductive urethane rubber or silicone rubber containing fine carbon particles or the like, and its surface is coated with urethane rubber or fluorine-containing silicone rubber. The developing roller shaft 52 is supported in the side wall 69 of the developer side housing 36 in the developing chamber 42 .

The developer roller 38 is supported in the side wall 69 so as to protrude from the developer side housing 36 through the rear opening 94 . More specifically, through-holes 121 are formed in both side walls 69 of the developer-side housing 36 at positions near the rear end of the developer-side housing 36 and are opposed to each other in the width direction. The developing roller shaft 52 is inserted through the through hole 121 so that the developing roller 38 is rotatably supported in the developer side housing 36, and the vertical center portion of the rubber roller 53 protrudes to the outermost side of the developer side housing 36 through the rear opening 94. far away.

The developing roller 38 is driven to rotate counterclockwise in FIG. 11 by a driving force input to the developing roller shaft 52 from a motor (not shown). Further, a developing bias is applied to the developing roller 38 during the developing operation.

The thickness regulating blade 39 is arranged above the rear portion of the developing roller 38 and a plate wall 49 described later in the developing chamber 42 . The blade mounting portion 73 supported on the rear side of the side wall 69 holds the thickness regulating piece 39 at both lateral ends thereof.

The thickness regulating piece 39 includes a main blade member 54 formed of a metal leaf spring that is rectangular in front view (see FIG. 13 ), and a pressure portion 55 provided on the top end of the main blade member 54 . The main blade member 54 includes an upper end 83 which is a bottom end mounted in the blade mounting portion 73 , and a lower end 84 which is a top end where the pressure portion 55 is disposed. The pressure portion 55 has a semicircular cross section and is formed of insulating silicone rubber.

As shown in FIG. 13 , the thickness regulating piece 39 extends in the width direction along the rear surface of the blade mounting portion 73 . As shown in FIG. 11 , a mounting member 109 secures the upper end 83 of the main blade member 54 to the rear surface of the blade mounting portion 73 supported at both lateral ends in the rear end of the side wall 69 .

A sealing member 110 is interposed between the rear surface of the blade mounting portion 73 and the mounting member 109 to prevent toner from leaking therebetween.

The mounting member 109 includes a plate-shaped front support member 115 , a rear support member 111 having a substantially L-shaped cross-section, and screws 112 . The front support member 115 is disposed on the rear side of the sealing member 110 . The upper end 83 of the main blade member 54 is arranged on the rear side of the front support member 115 , and the rear support member 111 is arranged on the rear side of the upper end 83 . Screws 112 are inserted in a front-rear direction through the rear support member 111 , the upper end 83 of the main blade member 54 and the front support member 115 to secure these components together. Screws 130 fix the upper end 83 of the main blade member 54 and the mounting member 109 to the blade mounting portion 73 and the sealing member 110 interposed therebetween.

Accordingly, the main blade member 54 is arranged such that the upper end 83 is supported on the rear surface of the blade mounting portion 73 inclined downwards and forwards, and the lower end 84 in turn extends diagonally downwards and forwards from the upper end 83 to the supply roller 37, close to The developing roller 38 and the plate wall 49 therebetween. Therefore, the thickness adjusting piece 39 extends downward and forward from the upper end 83 to the lower end 84 , and gradually approaches the panel wall 49 .

The pressure portion 55 extends in the width direction along the rear surface of the lower end 84 of the main blade member 54 . The pressing portion 55 is pushed rearward by the elastic force of the main blade member 54 to press-contact the rubber roller 53 of the developing roller 38 at a position above and slightly rearward of the contact point between the developing roller 38 and the supply roller 37 .

The plate wall 49 is integrally formed with the top cover 70 and is arranged in the developing chamber 42 above the supply roller 37 and between the thickness regulating blade 39 and the partition wall 40 in the front-rear direction. As shown in FIG. 13 , the plate wall 49 has a rectangular plate shape in front view, extending through the developing chamber 42 in the width direction so as to partition the thickness regulating blade 39 from the toner containing chamber 41 . The panel wall 49 includes a bottom end 85 being an upper end and a free end 86 being a lower end.

The bottom end 85 of the plate wall 49 is connected to the bottom surface of the top cover 70 between the upper portion of the partition wall 40 and the blade mounting portion 73 . The free end 86 of the plate wall 49 extends vertically downwards from the bottom end 85 towards the supply roller 37 . The free end 86 of the plate wall 49 is positioned between the contact portion X where the pressure portion 55 of the thickness regulating blade 39 contacts the developing roller 38 (see FIG. 12 ) and the front edge of the supply roller 37 in the front-rear direction. In particular, the bottom end 85 of the panel wall 49 is aligned vertically with the sponge roller 51 of the supply roller 37 .

Therefore, the plate wall 49 extends vertically downward from the upper end to the lower end so that the free end 86 is close to the pressure portion 55 of the thickness regulating piece 39 and the supply roller 37 . With respect to the vertical direction, the free end 86 of the plate wall 49 extends below the pressure portion 55 and is separated from the supply roller 37 . Further, the upper end 83 and the lower end 85 of the thickness regulating piece 39 and the plate wall 49 are respectively supported on the top cover 70 , and the respective lower end 84 and free end 86 extend toward the supply roller 37 . Therefore, the top cover 70 , the thickness regulating piece 39 and the plate wall 49 form a substantially rectangular shape in cross section narrowing toward the bottom (ie, toward the supply roller 37 ). Here, the lower end 84 of the thickness regulating piece 39 and the free end 86 of the plate wall 49 are slightly separated in the front-rear direction.

As shown in FIG. 12 , the free end 86 of the plate wall 49 is positioned such that the shortest distance A between the free end 86 of the plate wall 49 and the surface of the sponge roller 51 on the supply roll 37 is in contact with the pressure portion 55 of the thickness regulating piece 39 The shortest distance B between the contact portion X of the developing roller 38 and the surface of the sponge roller 51 is short.

Therefore, as shown in FIG. 13 , the free end 86 of the plate wall 49 is positioned below the contact portion X where the pressure portion 55 of the thickness regulating blade 39 contacts the developing roller 38 .

When a driving force is input from a motor (not shown) to the agitator rotating shaft 46, the agitator rotating shaft 46 is driven to rotate clockwise in FIG. The circular direction movement of the rotating shaft 46 of the device. Thus, the agitating member 47 agitates the toner contained in the toner containing chamber 41 and discharges some of the toner to the developing chamber 42 through the opening 43 .

The toner discharged to the developing chamber 42 through the opening 43 is supplied onto the developing roller 38 by the rotating supply roller 37 . At this time, the toner is positively frictionally charged between the supply roller 37 and the developing roller 38 because the surfaces of the two rollers move in opposite directions at the point of contact. As the developing roller 38 rotates, the toner supplied onto the developing roller 38 from the supply roller 37 moves upward on the side portion of the supply roller 37 to the contact portion X where the pressure portion 55 of the thickness regulating blade 39 contacts the developing roller 38 . At this contact portion X, the toner passes between the pressure portion 55 of the thickness regulating blade 39 and the rubber roller 53 of the developing roller 38 . At this time, in order to maintain a thin layer of uniform thickness on the surface of the rubber roller 53 , the pressure portion 55 peels off excess toner.

In the developer cartridge 30 described above, the plate wall 49 is disposed between the thickness regulating blade 39 and the partition wall 40 and above the supply roller 37 for partitioning the thickness regulating blade 39 from the toner containing chamber 41 . The free end 86 of the plate wall 49 is positioned as the shortest distance A between the free end 86 of the plate wall 49 and the sponge roller 51 on the supply roller 37 than the contact portion X where the pressure portion 55 of the thickness regulating blade 39 contacts the developing roller 38 and the supply roller The shortest distance B between the sponge rollers 51 of 37 is short.

The toner is positively tribocharged between the supply roller 37 and the developing roller 38 rotating in the same direction so that the surface of the roller moves in the opposite direction at the contact area. As the developing roller 38 rotates, some charged toner reaches the contact portion X. As shown in FIG. At this time, the thickness regulating blade 39 peels off excess charged toner to form a thin layer of uniform thickness on the developing roller 38 . The excess toner peeled off by the thickness regulating blade 39 can be maintained between the thickness regulating blade 39 and the plate wall 49 and can be carried on the surface of the developing roller 38 again and regulated by the thickness regulating blade 39 .

As a result, since the excess toner peeled off by the thickness regulating blade 39 can be prevented from returning to the toner containing chamber 41, it is possible to reliably control the charging of the toner to prevent degradation of image quality.

Further, in the developer cartridge 30 of the illustrated embodiment, the partition wall 40 is arranged in the middle of the developer side casing 36 in the front-rear direction to partition the developer side casing 36 into the toner accommodating chamber 41 and the developing chamber 42, and the plate wall 49 is arranged in the developing chamber 42 . Therefore, when the toner flows from the area between the thickness regulating sheet 39 and the plate wall 49 , the partition wall 40 can prevent excess charged toner peeled off by the thickness regulating sheet 39 from returning to the toner containing chamber 41 .

Accordingly, the charged toner can be maintained in the developing chamber 42 , thereby further preventing the charged toner from returning to the toner containing chamber 41 . As a result, it is possible to more reliably control the charging of the toner and further prevent degradation of image quality.

Further, the plate wall 40 is arranged so that the bottom end 85 is connected to the top cover 70 of the developer side casing 36, and the free end 86 is arranged at the contact portion X where the pressure portion 55 of the thickness regulating blade 39 contacts the developing roller 38 and the supply roller 37 between the front sides in the front-rear direction.

With such a structure, even when the excess charged toner peeled off by the thickness regulating blade 39 flows along the plate wall 49 and flows forward from the free end 86 of the plate wall 49, the charged toner comes into contact with the supplying toner to the developing roller again. 38 on the supply roll 37 . Therefore, with a simple structure, the charged toner is reliably held between the thickness regulating sheet 39 and the plate wall 49, thereby reliably preventing the charged toner from returning to the toner accommodating chamber 41.

In the developer cartridge 30 of the illustrated embodiment, the thickness regulating blade 39 gradually approaches the plate wall 49 from the upper end 83 to the lower end 84, and the pressure portion 55 arranged on the lower end 84 contacts the developing roller 38 by the elastic pressure of the main blade member 54. The rubber roller 53. Therefore, such a simple structure can reliably prevent excess charged toner peeled off by the pressure portion 55 of the thickness regulating piece 39 at the contact portion X from flowing through the free end 86 of the plate wall 49 toward the toner containing chamber 41, thereby further preventing charged toner The toner returns to the toner containing chamber 41.

Further, in the developer side casing 36 described above, intersecting front and rear ribs 88 and lateral ribs 89 are provided on the top cover 70 to form a lattice structure. In addition, the forward protrusion 90 near the front of the top cover 70 is arranged at the front ends of the two front and rear ribs 88 closest to the lateral center of the top cover 70, and the stepped portion 91 and the lateral protrusion 100 are arranged at a distance from the top cover 70. 70 on the two front and rear ribs 88 closest to the outer lateral sides, and the rearward protrusion 93 is arranged at the rear ends of the two front and rear ribs 88 .

With such a structure, the outermost sides of the lattice formed by the intersecting front and rear ribs 88 and transverse ribs 89 are fitted into the top opening 95 so that the forward protrusion 90, the lateral protrusion 100 and the rearward protrusion 93 Corresponding interior surfaces of the top opening 95 are contacted. Therefore, the top cover 70 can be accurately mounted on the main casing 87 so that the plate wall 49 provided on the top cover 70 can be accurately arranged at a desired position in the developer side casing 36 .

The rearward protrusions 93, which are arranged at the rear ends of the two front and rear ribs 88 closest to the lateral sides of the top cover 70, have a height at the position where the blade mounting portion 73 is supported on the side wall 69, that is, with respect to the lateral center. The rigid position contacts the lateral end of the blade mount 73 . Therefore, this structure achieves stable positioning, improving the assembly accuracy of the top cover 70 on the main housing 87 .

Further, the forward protrusions 90 arranged at the front ends of the two front and rear ribs 88 closest to the transverse center of the top cover 70 contact the front wall 72 near the transverse center of the front wall 72, where the front wall 72 has a smaller Rigid and more likely to bend than the ends of the front wall 72 supported by the side walls 69 . Therefore, this structure can prevent the bending of the gear cover 82 in the lateral center.

While dimensional control of the contact area between the top cover 70 and the main housing 87 must be strictly enforced, as described above, the effort to achieve such control cannot be reduced by the fact that the control is localized.

In the developer cartridge 30 of the illustrated embodiment, since the surface of the supply roller 37 moves in a direction opposite to the surface of the developing roller 38 at the area in contact with the developing roller 38, the toner can be reliably tribocharged. Further, the developing roller 38 rotates so that the toner supplied from the supply roller 37 moves backward on the upper half of the developing roller 38 so that the toner moves upward on the side of the supply roller 37 to reach the pressure of the thickness regulating blade 39 The portion 55 contacts the contact portion X of the developing roller 38 . Therefore, since the surface of the supply roller 37 moves in the opposite direction to the surface of the developing roller 38 at the contact area therebetween, the surface of the supply roller 37 also moves backward at its upper half. Therefore, the supply roller 37 can easily return the excess charged toner that has been peeled off by the thickness regulating blade 39 to the developing roller 38, and the supply roller 37 can also easily supply the uncharged toner contained in the toner containing chamber 41 to the developing roller 38. On the developing roller 38.

The process cartridge 20 and the laser printer 1 of the illustrated embodiment include the developer cartridge 30, in order to reliably control the charging of the toner, by preventing the excessively charged toner peeled off by the thickness regulating sheet 39 from returning to the toner containing chamber 41, The developer cartridge 30 can prevent degradation of image quality. Therefore, the process cartridge 20 and the laser printer 1 can accurately develop the electrostatic latent image formed on the photosensitive drum 28 in order to accurately form the toner image, and thus, a high-quality image form can be achieved.

In the above-described embodiment, the developer cartridge 30 is detachably mounted on the drum cartridge 27 to form the process cartridge 20 , and the process cartridge 20 is detachably mounted in the main casing 2 . However, it is also possible to provide the photosensitive drum 28, the charger 29, the transfer roller 31, the cleaning member 32, and the like in the main casing 2, and remove the drum cartridge 27, and detachably install the developer in the main casing 2 box of 30. It is also possible to remove the drum cartridge 27 and the developer cartridge 30 and provide the photosensitive drum 28, the charger 29, the transfer roller 31, the cleaning member 32, and the like in the main housing 2, along with the toner accommodating chamber 41, the developing roller 38, Supply roll 37 , thickness regulating piece 39 and plate wall 49 .

Toner detecting windows 44 are formed in both side walls 88 of the housing 36 for detecting the amount of toner remaining in the toner containing chamber 41 . The toner detection windows 44 are formed at positions close to the side wall 88 of the partition wall 40 and are opposed to each other in the width direction. Toner detection window 44 is a transparent disc embedded in side wall 88 of housing 36 .

A toner sensor (not shown) including a light emitting element and a light receiving element is arranged outside the housing 36 opposite to the toner detection window 44 . The detection light emitted by the light emitting element enters the toner containing chamber 41 through one of the toner detection windows 44 . After passing through the toner containing chamber 41, the detection light is discharged through another toner detection window 44 and received by the light receiving element. The toner sensor is configured to detect the toner remaining in the toner accommodating chamber 41 by measuring the detection time when the detection light passes through the two toner detecting windows 44 and the toner in the toner accommodating chamber 41 is agitated by an agitator 45 described later. amount of powder.

Next, referring to Figs. 16 to 24C, the agitator 45 and the wiper 48 will be described in detail according to one illustrated embodiment.

In addition to the above-mentioned rotating shaft 46 , stirring member 47 and grid 49 , as shown in FIG. 16 , the stirrer 45 includes a light-shielding plate 89 and a guide plate 90 .

The stirring member 47 includes a sheet support member 65 extending radially outward from the rotation shaft 46 , and a sheet 66 mounted on the sheet support member 65 . The sheet support member 65 includes a plurality of spaced cross plates 68 spaced from each other in the width direction of the rotation shaft 46 , and a sheet support plate 69 connected to the rotation shaft 46 through the cross plates 68 . Each transverse plate 68 has a bottom end connected to the rotation shaft 46 and extends radially outward therefrom.

The sheet support plate 69 extends parallel to the rotation shaft 46 and is separated from the rotation shaft 46 by a predetermined distance and is connected to the top end of each cross plate 68 . Therefore, the rotating shaft 46, the horizontal plate 68 and the sheet support plate 69 are connected to form a stepped structure.

The sheet 66 has a bottom edge fixed to the sheet support plate 69 along the width direction of the rotation shaft 46 . As shown in FIG. 17, the thin piece 66 is divided into inclined pieces 70 whose free ends are inclined relative to the width direction, which are arranged at both ends in the width direction (equal to the width direction of the rotating shaft 46), and a slanted piece 70 inserted between the two slanted pieces 70 is formed. The free end of the rectangular piece 71 in the central part is shorter than the inclined piece 70 and aligned with the width direction.

As shown in FIG. 16 , the sheet 66 is fixed to the sheet support plate 69 at a predetermined obtuse angle with respect to the extending direction of the transverse plate 68 . As shown in FIG. 17 , the light blocking plate 89 is integrally formed with the horizontal plate 68 positioned just inside the outermost horizontal plate 68 in the width direction on one lateral end of the rotary shaft 46 . As shown in FIG. 16 , the light blocking plate 89 has a plate shape and extends in a plane at right angles to the axial direction of the rotation shaft 46 . The light blocking plate 89 functions to block the detection light emitted by the toner sensor at regular intervals to increase the detection accuracy of remaining toner.

The guide plate 90 extends radially outward from the rotation shaft 46 in a direction opposite to the direction of the sheet 66 . The guide plate 90 has a rectangular plate shape of substantially uniform thickness and is formed in an axial center region of the rotation shaft 46 extending in a direction opposite to the direction in which the transverse plate 68 extends. When the agitator 45 rotates, the guide plate 90 plays the role of distributing the toner evenly in the toner containing chamber 41 in its width direction, and accumulates the toner so that the toner is directed toward both lateral ends of the toner containing chamber 41. flow.

A fixing member 49 is placed at one of each lateral end of the rotation shaft 46 . As shown in FIG. 17 , each fixing member 49 is integrally configured with a supporting plate 72 , a clamping plate 73 , a connecting wall 74 and a restricting plate 75 . Each support plate 72 has a substantially rectangular plate shape in plan view. The support plate 72 is separated from the guide plate 90 by a predetermined distance in the width direction of the rotation shaft 46 (see FIG. 4 ), and extends in a direction opposite to the direction in which the horizontal plate 68 extends.

As shown in FIG. 23 , a first cutout portion 76 is formed in the support plate 72 . The first cutout 76 is substantially U-shaped in bottom view. The first cutout portion 76 is formed in a part of the support plate 72 opposite to the clamp plate 73 in an extended direction along which the support plate 72 extends from the rotation shaft 46 . The first cutout portion 76 moves from the downstream end in the insertion direction relative to the wiper 48 (the inner end in the axial direction of the rotation shaft 46 ) toward the upstream end in the insertion direction (towards the outer end in the axial direction of the rotation shaft 46 ). ). Here, the extended direction includes a direction from the bottom end of the support plate 72 connected to the rotation shaft 46 to a free end of the support plate 72 and a direction from the top end to the bottom end.

As shown in FIGS. 20 and 22 , the first cutout 76 surrounds a central portion 77 of the support plate 72 . A protrusion 78 arranged on the central portion 77 protrudes inwardly in a direction in which the support plate 72 faces the clamping plate 73 .

The protrusion 78 is arranged at the upstream end of the central portion 77 in the insertion direction and has an inclined surface 86 formed on an end portion thereof. The inclined surface 86 is inclined inwardly from the upstream side to the downstream side in the insertion direction in the direction in which the support plate 72 opposes the clamp plate 73 .

As shown in FIGS. 18 and 19 , the clamping plate 73 faces the support plate 72 across and through a gap corresponding to the thickness of the wiper 48 from the midpoint of the support plate 72 in the extending direction to the top end thereof.

As shown in FIGS. 20 and 22 , the splint 73 is formed in a portion opposite to the first cutout 76 and is substantially U-shaped in plan view, approximately the same in shape as the first cutout 76 . The second cutout portion 79 is formed in a region of the splint 73 opposite to the central portion 77 formed in the support plate 72 and is surrounded by the splint 73 .

A part of the clamping plate 73 extending in the extending direction of the support plate 72 along the upstream side of the second cutout portion 79 in the insertion direction serves as a pressure plate 80 . The pressure plate 80 acts to prevent the wiper 48 from lifting the support plate 72 .

The connecting walls 74 are parallel to each other in the insertion direction and are separated from each other by a predetermined gap corresponding to the width of the wiper 48 in the extending direction of the support plate 72 . The connection walls 74 connect the support plate 72 to both ends of the splint 73 in the extending direction.

With such a structure, a slit 81 for receiving the wiper 48 is formed in the fixing member 49 and defined by the support plate 72 , the clamping plate 73 and the connection wall 74 .

The restricting plate 75 is arranged along the downstream end of the supporting plate 72 with respect to the insertion direction and extends in the extending direction of the supporting plate 72 . The limiting plate 75 protrudes from the support plate 72 towards the region surrounded by the clamping plate 73 and connects the supporting plate 72 and the clamping plate 73 in the region of the supporting plate 72 opposite the clamping plate 73 .

The hook insertion portion 82 is provided as a cutout portion in the restriction plate 75 forming a gap in the extending direction of the support plate 72 so that the support plate 72 communicates with the central portion 77 . A concave portion 83 that is U-shaped in plan view is formed in a portion of the support plate 72 that communicates with the hook insertion portion 82 .

The rotating shaft 46, the sheet supporting member 65 of the agitating member 47, the fixing member 49, the light shielding plate 89, and the guide plate 90 of the agitator 45 are integrally formed of hard synthetic resin such as ABS resin, and the sheet 66 is formed of such as polyethylene for Soft flakes made of polyethylene terephthalate resin.

As shown in FIG. 20, the wiper 48 is plate-shaped and substantially rectangular in plan view. The wiper 48 is formed of a soft elastic member such as urethane rubber.

As shown in FIG. 19, the wiper 48 is formed with substantially the same width as the width in the extending direction of the slit 81 formed in the fixing member 49 (the wiper 48 in a direction at right angles to the insertion direction and the thickness direction size of). The thickness of the wiper 48 is substantially the same as the width of the opening formed by the slit 81 in the direction in which the support plate 72 faces the clamping plate 73, as shown in FIGS. 18 and 19 . The length of the wiper in the direction of insertion is approximately twice as long as the depth of the slot 81 in the direction of insertion, as shown in FIGS. 18 and 21 .

The wiper 48 has a through hole 84 formed therein with a circular cross section. When the wiper 48 is inserted into the slit 81 formed in the fixing member 49 , the through hole 84 formed in the wiper 48 is positioned at the protrusion 78 to receive the protrusion 78 there.

Next, the process of installing the wiper 48 in the fixing member 49 will be described with reference to FIGS. 7 , 8 and 11 .

As illustrated in FIG. 20 , the wiper 48 is positioned against the slit 81 and inserted into the slit 81 in the direction of the arrow. 24A to 24C illustrate the process of inserting the wiper 48 into the slit 81 . After the downstream end of the wiper 48 passes between the support plate 72 and the pressure plate 80 of the clamping plate 73 in the insertion direction, the downstream end contacts the protrusion 78 as shown in FIG. 24A . As the wiper 48 is inserted further, the wiper 48 flexes so that the downstream end of the wiper 48 slides over the protrusion 78, as shown in FIG. 24B. As shown in Fig. 24C, the wiper 48 has been inserted until the downstream end contacts the restricting plate 75, which prevents further downstream movement in the direction of insertion. At this time, the protrusion 78 is received in the through opening 84 so as to penetrate the wiper 48 in the same thickness direction. When the protrusion 78 is received in the through opening 84 , the wiper 48 is inserted between the support plate 72 and the clamping plate 73 and is thus mounted in the fixing member 49 .

When the wiper 48 is installed in the fixing member 49 , as shown in FIG. 21 , the protrusion 78 is inserted through the through hole 84 , preventing the wiper 48 from being removed from the fixing member 49 . Further, the pressure plate 80 restricts the wiper 48 from rising from the support plate 72 , thereby fixing the wiper 48 in the fixing member 49 .

However, the wiper 48 can be removed from the securing member 49 using the sharpened needle hook 85 shown in phantom in Figure 24C. A hook 85 is inserted through the hook insertion portion 82 between the downstream end of the wiper 48 in the insertion direction and the recess 83 of the support plate 72 to lift the downstream end of the wiper 48 from the support plate 72 . In this state, the through hole 84 can be lifted off the protrusion 78 so that the wiper 48 can then be pulled out of the slot 81 and removed from the fixing member 49 .

In the agitator 45 described above, the wiper 48 is fixed to the fixing member 49 by being inserted into the slit 81 of the fixing member 49 , and thus is fixed to the agitating member 47 of the agitator 45 via the fixing member 49 . Further, the fixing member 49 is integrally formed with the stirring member 47 . Therefore, the wiper 48 can be fixed to the stirring member 47 by simple assembly that does not require special parts such as double-sided tapes or thrust nuts to fix the wiper 48 to the stirring member 47 . Therefore, such a structure reduces the number of required parts and improves the efficiency of assembly operations. Further, since the wiper 48 is fixed to the fixing member 49 through the insertion slit 81, the wiper 48 can be easily removed, making the wiper 48 more suitable for recycling.

The wiper 48 is inserted and held between the supporting plate 72 and the clamping plate 73, thereby securely fixing the wiper 48 with a simple structure.

Further, with respect to the opposing portions of the support plate 72 and the clamp plate 73 between which the wiper 48 is inserted, a first cutout portion 76 facing the clamp plate 73 is formed in the support plate 72, and a second cutout portion facing the support plate 72 79 is formed in the splint 73 . In other words, only one of the supporting plate 72 and the clamping plate 73 is formed at the opposite portion of the supporting plate 72 and the clamping plate 73 between which the wiper 48 is inserted, thereby facilitating the removal of the members when molding the supporting plate 72 and the clamping plate 73 . Further, toner entering the gap 81 can be easily removed during recycling.

When the wiper 48 is inserted into the slit 81 formed in the fixing member 49, the protrusion 78 is inserted into the through hole 84 formed in the wiper 48, thereby more securely fixing the wiper 48 to the fixing member 49, and passing Extended to the stirring member 47.

The inclined surface 86 of the protrusion 78 is formed to be inclined inwardly in the direction in which the support plate 72 faces the clamping plate 73 from the upstream to the downstream side in the insertion direction.

The inclined surface 86 of the protrusion 78 guides the wiper 48 in an inclined direction when the wiper 48 is inserted downstream into the fixing member 49 . As the downstream end of the wiper 48 slides over the protrusion 78 , the protrusion 78 begins to insert into the through hole 84 of the wiper 48 . This structure enables the wiper 48 to be installed smoothly.

After the protrusion 78 is inserted into the through hole 84 of the wiper 48 , the protrusion 78 prevents removal of the wiper 48 since the inclined surface 86 of the protrusion 78 is on the downstream side in the direction of removing the wiper 48 .

Further, when the wiper 48 is installed in the fixing member 49 , the pressure plate 80 restricts the wiper 48 from floating the support plate 72 , thereby reliably preventing the through hole 84 of the wiper 48 from slipping off the protrusion 78 . In this way, the wiper 48 can be firmly fixed.

Further, when the wiper 48 is mounted in the fixing member 49, the restricting plate 75 restricts the wiper 48 from being excessively inserted downstream, thereby securely fixing the wiper 48 at a predetermined position.

In order to remove the wiper 48 from the fixing member 49 , a hook 85 is inserted through the hook insertion portion 82 so that the developing chamber 42 can be easily peeled off from the support plate 72 . In this way, it is convenient to recycle.

Further, since the wiper 48 is formed of a soft elastic material such as urethane rubber, the wiper 48 is easily bent when installed into or removed from the fixing member 49 , so that the opening 84 can be inserted into or removed from the protrusion 78 . As a result, this structure facilitates the insertion of the wiper 48 into the slit 81 and can improve the efficiency of the assembly operation. This structure also facilitates removal of the wiper 48 from the slot 81, making the wiper 48 more suitable for recycling.

Since the developer cartridge 30 of the illustrated embodiment can be composed of fewer parts and can provide a more efficient assembly process, as described above, the process cartridge 20 equipped with the developer cartridge 30 and the laser printer 1 equipped with the process cartridge 20 can Manufactured at a lower cost and better suited for recycling.

By using a structure for inserting the wiper 48 into the slit 81 of the fixing member 49 in the toner containing chamber 41 and fixing the wiper 48 to the fixing member 49, the developer cartridge 30 described above has the following effects. By eliminating the need for such special parts, this structure prevents contamination from the double-sided tape or other special parts from entering the toner contained in the toner containing chamber 41 which is supplied for development. Further, this mechanism prevents chemical reaction between the toner and the adhesive layer of the double-sided tape.

In the illustrated embodiment described above, the protrusions 78 are arranged on the support plate 72 and on the pressure plate 80 on the clamping plate 73 . However, the protrusion 78 may instead be arranged on the clamping plate 73 and the pressure plate 80 on the support plate 72 .

In the illustrated embodiment described above, the through hole 84 is formed in the wiper 48 to insert the protrusion 78 . However, the receiving portion of the present invention for receiving the protrusion 78 does not have to be the through hole 84 if the receiving portion can receive the protrusion 78 inserted in the thickness direction of the wiper 48 . For example, a slit 87 that is substantially U-shaped in plan view may cut through the wiper 48 in the thickness direction, as shown in FIG. 25A . With this structure, the groove 87 can receive the protrusion 78 inserted through the wiper 48 in the width direction, as illustrated in FIG. 25B .

Further, in the above-described embodiment, the guide plate 90 of the agitator 45 is formed with a uniform thickness. However, it is possible instead to form the guide plate 90 thicker in the center region (with respect to the width direction of the rotation shaft 46 ) and become thinner toward the lateral ends (outer ends of the rotation shaft 46 in the width direction). When the agitator 45 rotates to agitate the toner, the surface of the guide plate 90 scraping off the toner is formed as an inclined surface on which the center portion of the guide plate 90 is on the upstream side in the rotation direction of the agitator 45 and Both lateral ends of the guide plate 90 are on the downstream side.

The guide plate 90 formed in this way can guide a smoother flow of toner toward the lateral side of the toner containing chamber 41 . Therefore, the guide plate 90 can more uniformly distribute the toner in the toner containing chamber 41 in the width direction of the toner containing chamber 41 .

Note that the flakes 66 and wiper 48 have been omitted from the agitator 45 shown in FIG. 26 .

Next, the shaft support unit 250 will be described in detail with reference to FIGS. 27 to 30 . As will be described in detail below, the shaft support unit 250 is disposed on the inner wall of the developer accommodating chamber 222 . The shaft support unit 250 includes a guide groove 250 for mounting the agitator shaft 223a, and a holding portion 250b for rotatably holding the agitator shaft 223a (see FIG. 28 ).

One end of the agitator shaft 223 a is rotatably held in a through hole (not shown) formed in the inner wall of the developer accommodating chamber 222 opposite to the inner wall where the shaft supporting unit 250 is provided. The same end of the agitator shaft 223a is fitted into a gear (not shown). A motor (not shown) provided in the laser printer 1 transmits driving force to the agitator shaft 223a through gears.

As shown in FIG. 27 , the other end of the agitator shaft 223 a is rotatably held in the shaft support unit 250 . As shown in FIGS. 28 and 30, the shaft supporting unit 250 includes a holding portion 250b for rotatably holding the agitator shaft 223a, a guide groove 250a for guiding the end of the agitator shaft 223a downward toward the holding portion 250b And a restricting portion 250c for restricting upward movement of the agitator shaft 223a held in the retaining portion 250b forms a boundary between the retaining portion 250b and the guide groove 250a.

As shown in FIG. 30 , the holding portion 250 b and the guide groove 250 a form a concave portion in the inner wall of the developer accommodating chamber 222 . The concave guide groove 250a is shallower than the concave holding portion 250b in the concave direction as shown in FIG. 30 .

The guide groove 250a has a shaft-facing surface 501a that faces the shaft end of the agitator shaft 223a when the agitator 223 is loaded into the developer accommodating chamber 222 . The axial facing surface 501a is inclined downward and in a direction opposite to the concave direction.

The restricting portion 250c has an inclined surface 501c formed continuously with the shaft facing surface 501a. The inclined surface 501c is inclined downward, that is, toward the holding portion 250b and away from the shaft facing surface 501a in a direction opposite to the concave direction.

An introduction surface 254 is also formed on the inner wall of the developer accommodating chamber 222 . The introduction surface 254 is inclined in a concave direction toward the guide groove 250a from a position deeper than the guide groove 250a, and is formed continuously with the open side 502a in the top of the axial facing surface 501a.

As shown in FIG. 28 , the guide groove 250 a has a side surface 503 a for restricting the movement of the agitator shaft 223 a in a direction at right angles to the guiding direction in which the agitator shaft 223 a is guided toward the holding portion 250 b. A gap 250e is formed between the side surface 503a of the guide groove 250a and the restricting portion 250c. The gap 25Oe is smaller than the diameter of the agitator shaft 223a.

The holding portion 250b has a polygonal shape in a cross section taken at right angles to the axial direction of the agitator shaft 223a. In this embodiment, the retaining portion 250b is substantially square in this cross-section.

The widths of the guide groove 250a and the holding portion 250b are the same in a direction at right angles to the guide direction of the agitator shaft 223a.

As shown in FIG. 27, a transparent window 251 (only one is shown in FIG. 27; the other is provided in the inner wall of the developer accommodating chamber 222 opposite to the wall provided with the shaft support unit 250) is provided in the developer. In the side wall of the accommodation cavity 222 . A light source (not shown) arranged outside the developer cartridge 216 transmits a light beam through the transparent window 251 for detecting the amount of remaining toner in the developer accommodating chamber 222 . To clean the transparent window 251, a soft wiper 253 is disposed on the agitator 223 to slidably contact the transparent window 251 when the agitator 223 rotates. The slope part 260 is formed on the side of the shaft support unit 250 contacted by the soft wiper 253 .

Next, referring to FIG. 30 , the operation of installing the agitator 223 in the developer accommodating chamber 222 will be described. First, one end of the agitator shaft 223 a is fitted into a through hole (not shown) formed in the developer containing chamber 222 . Next, the other end of the stirrer 223 is lowered into contact with the side 502a. The guide groove 250a guides the other end of the agitator shaft 223a toward the restricting portion 250c when the agitator shaft 223a is bent. Next, the other end of the agitator shaft 223a is guided downward along the inclined surface 501c, thus forcing the other end of the agitator shaft 223a to move upward to the restricting portion 50c in a direction opposite to the concave direction. When the other end of the agitator shaft 223a is pushed down, the end slides over the restriction 250c and fits into the retainer 250b. At this point, the agitator shaft 223a resumes its straight extension.

Since the guide groove 250a formed on the inner wall of the developer accommodating chamber 222 is narrower in the concave direction than the holding portion 250b, the agitator shaft 223a can be guided toward the restricting portion 250c from the narrow position. This reduces the amount by which the agitator shaft 223a must bend to slide over the restricting portion 250c, thereby reducing the load applied to the agitation compared with the load applied when the guide groove 250a and the holding portion 250b are formed to the same depth in the concave direction. The load of the device shaft 223a.

Since the restricting portion 250c has the inclined surface 501c connected to the shaft-facing surface 501a for inclining downward and in the direction opposite to the concave direction, when the end of the agitator shaft 223a slides over the restricting portion 250c, the agitator shaft 223a is slightly curved. As a result, this structure can reduce the load applied to the agitator shaft 223a.

The inner wall of the developer accommodating chamber 222 includes an introduction surface 254 inclined toward the guide groove 250a and is connected to an open end at the top of the shaft facing surface 501a. Therefore, the agitator shaft 223a can be smoothly guided to the open end of the top of the shaft facing surface 501a.

A gap 250e having a smaller diameter than the agitator shaft 223a is formed between the side surface 503a and the restricting portion 250c. Therefore, the toner accumulated in the holding portion 250b can leak through the gap 250e. Therefore, this structure can prevent toner from accumulating between the agitator shaft 223 a and the holding portion 250 b and prevent the agitator 223 from rotating.

In a cross section taken at right angles to the axial direction of the agitator shaft 223a, the holding portion 250b is substantially square. Therefore, the outer peripheral surface of the agitator shaft 223a points into contact with the holding portion 250b, reducing the frictional force generated between the outer peripheral surface of the agitator shaft 223a and the holding portion 250b.

It is possible to minimize the space required for the guide groove 250a by forming the guide groove 250a and the holding portion 250b with the same width in a direction at right angles to the direction in which the agitator shaft 223a is guided.

The slope part 260 is formed on the side of the shaft support unit 250 contacted by the soft wiper 253 so as to improve degradation of the soft wiper 253 due to sliding contact with the shaft support unit 250 .

The axial facing surface 501a of the guide groove 250a is inclined downward in a direction opposite to the concave direction. With such a structure, when installed in the developer accommodating chamber 222, the agitator shaft 223a is bent more slightly, and thus less load is applied to the agitator shaft 223a.

Although the invention has been described with reference to specific embodiments, various modifications may be made by those skilled in the art without departing from the scope of the invention.

The process cartridge 20 and the developer cartridge 30 described by the embodiment include the plate wall 49 extending vertically downward from the bottom end 85 toward the supply roller 37 so that the free end 86 of the plate wall 49 is positioned close to the outer peripheral surface of the supply roller 37 . However, the process cartridge 20 or the developer cartridge 30 may be modified as shown in FIG. 2B and retain a number of novel technical features and advantages as described above. In the modified process cartridge 20' shown in Figure 2B, the vertical length of the wall 49' is shortened with respect to the wall 49 shown in Figure 2A, Figure 11, Figure 12 and Figure 15, so that the wall 49' The free ends 86 are spaced a large distance away from the outer peripheral surface of the supply roller 37 .

Claims (8)

1, a kind of developer box comprises:

Have the developer that developer is carried outer surface thereon and carry member;

Have the position that is formed on the uncovered and exposure in uncovered wherein and support the shell that developer carries member, uncovered have an edge; With

It is characterized in that, developer box further comprise formed box-like substantially and along uncovered edge placement to reinforce the strenthening member at this edge.

2, developer box as claimed in claim 1 is characterized in that, wherein strenthening member with along with the xsect of the direction quadrature of uncovered longitudinal edge in form three limits of rectangle.

3, developer box as claimed in claim 1 is characterized in that, wherein to carry member be the form with roller of turning axle to developer; And strenthening member is extended along the turning axle of developer roll.

4, developer box as claimed in claim 1 is characterized in that, further comprises being set on the uncovered edge and in order to prevent that developer is configured to stop the sheet members in described space by the air gap leakage that uncovered limit and developer carry between the member.

5, developer box as claimed in claim 4 is characterized in that, wherein uncovered edge with in the xsect of the direction quadrature at uncovered edge, have the stepped form that comprises a plurality of steps; And wherein thereby sheet members is fixed in the downstream edge alignment of the upstream step of developer by the step in the downstream farthest of the direction of uncovered leakage with this upstream step.

6, developer box as claimed in claim 1 is characterized in that, thus wherein developer to carry member supported in the enclosure by uncovered being projected into outside the shell that is formed on wherein.

7, developer box as claimed in claim 1, it is characterized in that wherein shell comprises with strenthening member and forming continuously and the guiding elements of leader record medium when being carried at developer and carrying the developer image that is formed by developer on the member and be transferred on the recording medium.

8, developer box as claimed in claim 7 is characterized in that, a plurality of guiding elements wherein are set, and guiding elements is spaced on the direction that the bearing of trend with strenthening member intersects with interval.

Images