CN1854927A - Image forming device and removable cartridge - Google Patents

Abstract

The image forming apparatus of the present invention includes: an electrostatic latent image bearing member; a toner cartridge; a developing member; a transfer member; The toner cartridge is connected with the developing device in a removable manner. The developing device incorporates a developing member therein. When the toner container is connected to the developing device, the circulation part can always be operated regardless of whether the developing part is in operation, so that the toner circulates between the developing device and the toner container.

Description

Image forming device and removable cartridge

Cross References to Related Applications

This application claims priority from Japanese Patent Application No. 2005-53706 filed on February 28, 2005 and Japanese Patent Application No. 2005-208443 filed on July 19, 2005. The entire contents of each of the above priority applications are incorporated herein by reference.

Technical field

The present invention relates to an electrophotographic type image forming apparatus in which an electrostatic latent image formed on a latent electrostatic image bearing body is developed into a toner image, and the toner image is transferred onto a recording medium, and an image forming apparatus used in the image forming apparatus box.

Background technique

There has been proposed an image forming apparatus comprising: an image carrier having an electrostatic latent image formed on its surface; a toner cartridge storing toner for developing the electrostatic latent image; A developing unit that develops an electrostatic latent image into a toner image by triboelectrically charging and adding toner to the surface of an image carrier; transfer printing for transferring a toner image from an image carrier to a recording medium a component; and a developing device in which at least the developing component is combined and a toner cartridge is removably provided. In such an image forming apparatus, after an electrostatic latent image is formed on the surface of an image carrier, a developing member applies triboelectric charging toner from a toner cartridge to the surface of the latent electrostatic image carrier, thereby developing the latent image. Thus, a toner image is formed. Then, the transfer member transfers the toner image to the recording medium. As a result, an image corresponding to the electrostatic latent image is formed on the recording medium. Since the toner cartridge is removable from the developing device in which the developing unit is incorporated, the toner cartridge can be replaced with a new one when the toner runs out. Therefore, image formation is continued.

U.S. Patent No. 5,867,756 has proposed an image forming apparatus of the above-mentioned type, wherein a supply member such as an agitator is provided in the toner container for supplying toner from the toner container to a developing device whose A return member, such as a screw conveyor roller, is provided in the housing to return the toner from the developing device to the toner container. The supply part and the return part operate simultaneously, thereby circulating the toner between the developing device and the toner container. This prevents the toner from agglomerating and hardening at specific locations. Ensure the fluidity of toner and improve image quality.

However, the image formed by such an image forming apparatus may deteriorate in quality when the toner cartridge is replaced with a new one. When an image forming apparatus repeatedly performs an image forming action, toner performance deteriorates. Toner, especially non-magnetic one-component toner, is repeatedly charged in friction as toner particles repeatedly move in sliding contact with a developing roller and a layering regulation member provided in an image forming apparatus, resulting in poor performance. Therefore, the chargeability of such deteriorated toner is lowered. Thus, in some cases, old toner subjected to repeated triboelectric charging and new toner not subjected to triboelectric charging differ in chargeability. If new and old toners are mixed, they cannot be charged to the same polarity. New toner will be positively charged, while old or degraded toner will be negatively charged. Negatively charged old toner will adhere to those positively charged electrostatic latent image portions, ie, those portions of the electrostatic latent image that should be developed as white solids or blanks in the toner image. As a result, a so-called print fogging phenomenon occurs.

Contents of Invention

SUMMARY OF THE INVENTION In view of the above circumstances, an object of the present invention is to provide an image forming apparatus and a cartridge capable of preventing the occurrence of printing fogging.

To achieve the above and other objects, the present invention provides an image forming apparatus comprising: an electrostatic latent image bearing member; a toner cartridge; a developing member; a transfer member; The latent electrostatic image bearing member has a surface on which a latent electrostatic image is formed. The toner cartridge stores toner. The developing part supplies toner from the toner container onto the surface of the latent electrostatic image bearing member, thereby developing the latent electrostatic image into a toner image. The transfer member transfers the toner image from the surface of the latent electrostatic image bearing member to the recording medium. The toner cartridge is removably connected to the developing device. A developing member is incorporated in the developing device. The circulation means is operable when the toner container is connected to the developing device, so that the toner is always circulated between the developing device and the toner container regardless of whether the developing means is in operation.

According to another aspect, the present invention provides a removable cartridge used in an image forming apparatus, comprising: a receiving portion for detachably receiving a toner cartridge storing toner; a developing part that applies toner to the surface of the image carrier, thereby developing an electrostatic latent image formed on the image carrier; and a return part that returns the toner from the cartridge to the toner container, regardless of the developing part Does work always works.

According to another aspect, the present invention provides a removable toner cartridge, which is configured to be connected to a developing device, and the developing device at least includes a developing component, and the developing component causes the toner to add color to the surface of the image carrier through frictional electrification. powder to develop the electrostatic latent image formed on the surface of the image carrier into a toner image. The unit supplies the toner stored in the toner cartridge.

According to another aspect, the present invention provides an image forming apparatus including: a latent electrostatic image bearing member; a toner cartridge; a developing member; a transfer member; The latent electrostatic image bearing member has a surface on which a latent electrostatic image is formed. The toner cartridge stores toner. The developing part supplies toner from the toner container onto the surface of the latent electrostatic image bearing member, thereby developing the latent electrostatic image into a toner image. The transfer member transfers the toner image from the surface of the latent electrostatic image bearing member to the recording medium. The toner cartridge is removably connected to the developing device. A developing member is incorporated in the developing device. The supply part supplies toner from the toner container to the developing device. The return part returns the toner from the developing unit to the toner container. The return part is able to work independently of the work of the supply part.

According to another aspect, the present invention provides a removable cartridge used in an image forming apparatus including: a receiving portion for detachably receiving a toner cartridge storing toner, and provided with a supplying part for supplying toner to a developing part ; the developing part, which supplies toner from the toner container to the surface of the electrostatic latent image carrier, thereby developing the electrostatic latent image formed on the image carrier; and the return part which returns the toner to the toner container, returning Parts are able to work independently of the supply work that supplies the parts.

With the above arrangement, the occurrence of printing fogging can be prevented.

Description of drawings

Fig. 1 is the perspective view of the laser printer of the first embodiment of the present invention;

Figure 2 is a perspective view of the laser printer illustrating how to open the cover of the laser printer;

3 is a perspective view of the laser printer illustrating how to pull out the paper cassette from the main body of the laser printer;

Fig. 4 is a sectional view showing the internal structure of the laser printer cut along line IV-IV in Fig. 2;

5 is a sectional view of the laser printer illustrating how the photosensitive drum cartridge, the developing cartridge, and the toner cartridge are removed from the laser printer main body as an integral unit;

Figure 6 is a sectional view of a laser printer illustrating how to disconnect the toner cartridge from the developer cartridge;

7 is a sectional view of the laser printer illustrating how to remove only the toner cartridge from the laser printer main body;

8 is a sectional view of the laser printer illustrating how the developing cartridge and the toner cartridge are removed from the laser printer main body as an integral unit;

Fig. 9 is a left side view of the photosensitive drum cartridge from which the developing cartridge and the toner cartridge are removed;

Figure 10 shows the configuration of the inner surface of the left side wall in the main body of the laser printer;

Figure 11 is a left side view showing a state in which the toner cartridge and the developing cartridge are connected to each other;

Figure 12A is a front view of the toner container holder in the developing cartridge viewed from the side of the toner cartridge when the toner cartridge is disconnected from the developing cartridge;

Figure 12B is a rear view of the toner cartridge viewed from the toner cartridge holder side when the toner cartridge is disconnected from the developing cartridge;

Figure 12C is a front view of the toner container holder in the developing cartridge viewed from the side of the toner container when the toner container is connected to the developing cartridge;

Figure 12D is a rear view of the toner cartridge viewed from the toner cartridge holder side when the toner cartridge is connected to the developing cartridge;

Fig. 13 is a right side view showing a state in which the toner container and the developing cartridge are connected to each other;

Figure 14 is a sectional view illustrating the internal structure of a toner container and a developing cartridge when they are connected to each other;

Figure 15 is a cross-sectional view of the developing cartridge cut along the arrangement line of the screw conveying roller;

16 is a block diagram illustrating the configuration of a control system incorporated therein in the laser printer;

Fig. 17 is a flowchart illustrating processing performed by the control system;

Fig. 18A is a left side view showing a state in which a toner container and a developing cartridge according to a modification of the first embodiment are connected to each other;

Fig. 18B is a left side view showing the state in which the toner container and the developing cartridge according to the modification of the first embodiment are connected to each other, in which some gears shown are hidden and are not shown in Fig. 18A.

Figure 19 is a sectional view illustrating the internal structure of the toner container and the developing cartridge when they are connected to each other;

Fig. 20 is a left side view showing a state in which the toner container and the developing cartridge are connected to each other according to the second embodiment;

Figure 21 is a right side view showing a state in which the toner container and the developing cartridge are connected to each other according to the second embodiment;

22A is a front view of the toner container holder in the developing cartridge viewed from the toner container side when the toner container is disconnected from the developing cartridge according to the second embodiment;

Fig. 22B is a rear view of the toner cartridge viewed from the toner cartridge holder side when the toner cartridge is disconnected from the developing cartridge according to the second embodiment;

Figure 22C is a front view of the toner container holder in the developing cartridge viewed from the toner container side when the toner container is connected to the developing cartridge according to the second embodiment;

22D is a rear view of the toner container viewed from the toner container holder side when the toner container is connected to the developing cartridge according to the second embodiment;

Fig. 23 shows the configuration of the inner surface of the left side wall in the main body of the laser printer according to the second embodiment;

24 is an enlarged view showing the configuration of a part of the inner surface of the left side wall in the main body of the laser printer shown in FIG. 23;

25 is an enlarged view showing the configuration of a part of the inner surface of the right side wall in the main body of the laser printer according to the second embodiment;

Fig. 26 is a block diagram illustrating the configuration of a control system incorporated in a laser printer according to the second embodiment; and

Fig. 27 is a flowchart for explaining processing performed by the control system according to the second embodiment.

Detailed ways

An image forming apparatus according to various embodiments of the present invention will be described below with reference to the drawings in which the same parts and components are denoted by the same reference numerals to avoid duplication of description.

FIG. 1 is a perspective view showing the appearance of a laser printer 1 according to a first embodiment of the present invention. The laser printer 1 is used to form an image using a non-magnetic one-component toner having a positively charged property. A representative example of the toner is a styrene-propylene polymerized toner.

The terms "upward", "downward", "upper", "lower", "above", "below", "below", "left", "right" etc. used throughout the description assume that the laser printer 1 is The orientation setting that will be used. The laser printer 1 in use is placed as shown in FIG. 1 . The left-right direction defined for the laser printer 1 is equivalent to the width direction of paper conveyed in the laser printer 1 .

As shown in FIG. 1 , a cover 2 is provided to cover the outer periphery of the main body of the laser printer 1 . The carton 3 is installed under the cover 2 .

As shown in FIG. 2, the cover 2 defines an opening 2a on its front side, and has a cover 4 capable of opening and closing the opening 2a. Normally, the cover 4 closes the opening 2a as shown in FIG. 1 .

The cover 4 has finger rests 4a on its upper left and right sides, respectively. The user puts his finger into this finger seat 4a to hold the cover 4, and then pulls the cover 4 open. As a result, as shown in FIG. 2, the cover 4 is rotated about the hinge 4b at the lower edge of the cover 4, thereby opening the opening 2a.

As shown in FIG. 3 , the paper cassette 3 can be pulled forward from the main body of the laser printer 1 . Thus, the paper cassette 3 can be removed from the main body of the laser printer 1 .

As shown in Figure 4, spring 6 and support plate 5 are installed in the carton 3. The spring pushes up the supporting plate 5 upwards. The paper feed roller 9 is provided above the front edge of the support plate 5 . Paper feed rollers 9 feed paper (not shown) placed on support plate 5 to image forming unit 7 one at a time. Along the paper conveying path from the paper conveying roller 9 to the image forming unit 7 , a conveying roller 11 , a guide 13 , and a pair of registration rollers 14 , 15 are sequentially arranged. The transport roller 11 transports paper in cooperation with the paper transport roller 9 . The guide 13 receives the paper conveyed by the conveying roller 11 along the outer circumference of the conveying roller 11 and reverses the paper by about 180 degrees. The registration rollers 14, 15 are stopped at proper timing to catch the leading edge of the paper and eliminate skewing of the paper.

The image forming unit 7 includes a photosensitive drum 21 and a transfer roller 22 . The photosensitive drum 21 and the transfer roller 22 are installed in the photosensitive drum cartridge 20 . The transfer roller 22 faces the photosensitive drum 21 . A toner image is formed on the paper as the paper passes through the nip position between the photosensitive drum 21 and the transfer roller 22 . The paper is then sent to the fixing unit 31 .

In the fixing unit 31 , the toner image on the paper is fixed as the paper passes through the nip position between the heat roller 33 and the pressure roller 35 . The sheet of paper on which the toner image is now fused is then transported by a pair of transport rollers 36 .

The provided guide 37 guides the paper conveyed by the conveying roller 36 to the upper surface of the cover 2 . A pair of paper discharge rollers 38 discharges the paper to a paper tray 39 provided on the top surface of the cover 2 .

The scanning unit 90 is disposed between the paper tray 39 and the photosensitive drum cartridge 20 . The scanning unit 90 scans the photosensitive drum 21 with the laser beam L. As shown in FIG.

The image forming unit 7 and the scanning unit 90 will be described in more detail below.

The photosensitive drum 21 is rotatably supported in the photosensitive drum cartridge 20 . The photosensitive drum 21 has a photosensitive layer on its peripheral surface. A transfer roller 22 , a grid-controlled charger 23 , and a paper waste recycling brush 24 are also installed in the photosensitive drum cartridge 20 . The grid-controlled charger 23 is used to uniformly charge the surface of the photosensitive drum 21 . The photosensitive drum cartridge 20 is formed with an exposure opening 20a. The laser beam L emitted from the scanning unit 90 enters the photosensitive drum cartridge 20 through the exposure opening 20a. The laser beam L forms an electrostatic latent image on the photosensitive drum 21 .

The reed 26 provided on the photosensitive drum cartridge 20 holds the developing cartridge 40 on the photosensitive drum cartridge 20 . A handle 25 is provided on the free front end of the reed 26 . The developer cartridge 40 is detachably installed on the photosensitive drum cartridge 20 . The developing roller 41 is rotatably installed in the developing cartridge 40 . The developing roller 41 supplies toner onto the surface of the photosensitive drum 21 , thereby developing the electrostatic latent image into a toner image on the photosensitive drum 21 . Then, the toner image is transferred from the photosensitive drum 21 to the paper as the paper passes through the nip position between the photosensitive drum 21 and the transfer roller 22 .

The paper scrap collection brush 24 is in close contact with the surface of the photosensitive drum 21 at a position downstream in the rotational direction of the photosensitive drum 21 with respect to the position where the toner image is transferred from the photosensitive drum 21 to paper. A positive bias is applied to the paper dust collection brush 24 to remove negatively charged paper dust from the photosensitive drum 21 .

As shown in FIG. 4 , the developing roller 41 is rotatably supported in the developing cartridge 40 . The developing roller 41 is driven by a mechanism (described later) while being in contact with the photosensitive drum 21 .

Specifically, the developing cartridge 40 has a developing portion 40a and a toner container holding portion 40b. In the developing section 40 a , a developing roller 41 , an upper screw conveying roller 43 , a lower screw conveying roller 44 , a toner supply roller 45 , and a developing blade 47 are installed in a developing cartridge 40 .

The developing cartridge 40 has a toner container holder 42 in the toner container holding portion 40b.

The toner container holder 42 has a hollow cylindrical shape with an outer peripheral side wall and a pair of end walls (left and right side end walls) therein, and the front portions of the outer peripheral side wall and the end walls have openings. The toner container holder 42 detachably supports the toner container 60 on its inner surface, and exposes the front side of the toner container 60 . The toner container holder 42 is formed with an opening 42 a as shown in FIG. 7 . Toner is supplied from the toner container 60 into the developing section 40a through the opening 42a.

As shown in FIG. 15, the conveying screw rollers 43 and 44 receive toner from the toner container 60 through the opening 42a facing the central portion of the conveying screw rollers 43 and 44 in the axial direction. The screw conveying rollers 43 and 44 circulate the toner between their left and right end portions in the axial direction thereof.

The toner supply roller 45 receives toner from the upper and lower screw conveying rollers 43 and 44 and supplies the toner to the developing roller 41 . The developing blade 47 charges the toner supplied from the toner supply roller 45 onto the surface of the developing roller 41 by friction, and forms a thin layer of toner on the developing roller 41 .

The agitator 61 is rotatably supported in the toner container 60 . The agitator 61 rotates about its rotation shaft 61 a to agitate the toner in the toner container 60 , thereby supplying the toner to the developing cartridge 40 .

Next, the scanning unit 90 will be explained.

The scanning unit 90 includes a polygon mirror 91 , two mirrors 91 and 92 , an fθ lens 95 , and a cylindrical lens 97 . The polygon mirror 91 deflects and scans the laser beam L emitted from a laser emitting unit (not shown). The mirrors 92 and 93 reflect the laser beam L to guide the laser beam L to the photosensitive drum 21 . The fθ lens 95 is placed on the optical path extending from the polygon mirror 91 to the mirror 92 . The cylindrical lens 97 is placed on another optical path extending from the reflector 92 to the reflector 93 .

A laser unit (not shown) intermittently emits the laser beam L at an appropriate timing while rotating the polygon mirror 91 and the photosensitive drum 21 . As a result, an electrostatic latent image is formed on the surface of the photosensitive drum 21 . The developing roller 41 supplies toner to the photosensitive drum 21 to develop the electrostatic latent image into a toner image. Then, the toner image is transferred from the photosensitive drum 21 to paper. An image is thus formed on the paper according to the electron imaging method.

As shown in Figure 5, when the user opens the cover 4 and pulls the handle 25 provided on the photosensitive drum cartridge 20, the photosensitive drum cartridge 20, the developer cartridge 40 and the toner cartridge 60 are removed from the main body of the laser printer 1 through the opening 2a. .

The toner container 60 has a handle 62 . When the user rotates the handle 62 upward to the disengagement position shown in FIG. 6, the toner cartridge 60 is disengaged from the developing cartridge 40 in a manner described later. The user then pulls the handle 62, thereby removing only the toner cartridge 60 from the main body of the laser printer 1 through the opening 2a as shown in FIG.

As shown in FIG. 8, when the user presses down the handle 25 on the photosensitive drum cartridge 20, the reed 26 is also pressed down. The user then pulls the handle 62 forward without rotating the handle 62 upward. In this case, the toner cartridge 60 and the developer cartridge 40 are disassembled together as an integral unit from the drum cartridge 20 as shown in FIG. 8, and removed from the main body of the laser printer 1 through the opening 2a.

Each component in the image forming unit 7 will be described in detail below.

As described above, the handle 25 is fixedly fastened relative to the photosensitive drum cartridge 20 by the reed 26 . As shown in FIG. 9, the leaf spring 26 is bent upward at its midpoint to provide a bent portion 26a in the shape of a step. When the developing cartridge 40 is mounted on the drum cartridge 20 as shown in FIG. When the handle 25 is depressed as described above (refer to FIG. 8 ), the bent portion 26 a is disengaged from the lower edge of the toner container holder 42 . Therefore, the developing cartridge 40 can be connected and disconnected with respect to the photosensitive drum cartridge 20 .

As shown in FIG. 9 , the photosensitive drum 21 has metal shafts 21 a protruding outward from both left and right sides of the photosensitive drum cartridge 20 . The left end portion of the photosensitive drum 21 is provided with a gear 21b. The gear 21 b rotates integrally with the photosensitive drum 21 . A gear 21b protrudes from the rear end of the photosensitive drum cartridge 20 .

As shown in FIG. 10 , the guide groove 121 is formed on the inner surface of the left side wall of the main body of the laser printer 1 . The guide groove 121 serves to guide the rotation shaft 21 a of the photosensitive drum 21 . A gear 121b is provided in the main body of the laser printer 1 . The gear 121b can be driven by a drum motor 122 (refer to FIG. 16 ). The gear 121b is engaged with the gear 21b when the photosensitive drum cartridge 20 is placed in place in the main body of the laser printer 1 . Therefore, driving force is transmitted from the main body of the laser printer 1 to the photosensitive drum 21 .

As shown in FIG. 11, the drive shaft 51 is provided on the left side of the developing cartridge 40 at the developing section 40a. The driving shaft 51 is used to receive the driving force from the driving shaft 151 , and the driving shaft 151 is provided on the inner surface of the left side wall of the main body of the laser printer 1 as shown in FIG. 10 . The drive shaft 151 has a plate-shaped protrusion 151a at its shaft tip. The drive shaft 51 has a hollow cylindrical portion at its shaft tip and a pair of protrusions 51a provided in the hollow cylindrical portion. The pair of protrusions 51 a can be engaged with the plate-shaped protrusion 151 a of the drive shaft 51 . Therefore, the drive shaft 151 can be adapted to the drive shaft 51 . The drive shafts 51 and 151 form a so-called drive connection.

As shown in FIG. 11 , the gear 51b is mounted to the drive shaft 51 in a fixed manner. A gear 51b is on the outer surface of the left side wall of the developing cartridge 40 at the developing portion 40a. The gear 51b rotates integrally with the drive shaft 51 .

From the left side wall of the developing cartridge 40, a rotating shaft 41b of the developing roller 41 and a rotating shaft of the toner supply roller 45 protrude outward. The gear 41 a is fixed to the left end of the rotating shaft 41 b and rotates integrally with the developing roller 41 . The gear 45 a is fixed to the left end of the rotation shaft of the toner supply roller 45 , and rotates integrally with the toner supply roller 45 . Thus, the gear 41a and the gear 45a are located on the outer surface of the left side wall of the developing cartridge 40 at the developing portion 40a. The gear 51b is engaged with both the gear 41a and the gear 45a.

The toner cartridge 60 is connectable and disconnectable from the developing cartridge 40 . 12A and 12B show the state in which the toner container 60 is disconnected from the developer cartridge 40, that is, the handle 62 of the toner container 60 is rotated upward to the disconnected position shown in FIG. 6 . 12A shows the toner container holder 42 in the developing cartridge 40 viewed from the toner container 60 side, and FIG. 12B shows the toner container 60 viewed from the toner container holder 42 side.

As shown in FIG. 12B , the toner container 60 has an inner cylinder 63 and an outer cylinder 64 .

The inner cylinder 63 is a longitudinal hollow cylinder having an outer peripheral side wall and a pair of opposite end walls (left and right side end walls). The inner cylinder 63 stores toner therein. The rotation shaft 61 a of the agitator 61 extends along the central axis of the inner cylinder 63 . The rotation shaft 61 a protrudes outward from a pair of opposite end walls (left and right end walls) of the inner cylindrical body 63 . The gear 61 b is arranged at the right end of the rotating shaft 61 a and thus is located outside the right end wall of the inner cylinder 63 . The gear 61b rotates integrally with the rotating shaft 61a.

The outer cylinder 64 is coaxial with the inner cylinder 63 and surrounds the axial central portion of the inner cylinder 63 . The inner and outer cylinders 63 and 64 are coaxially supported by the cylindrical toner container holder 42 .

The outer cylindrical body 64 has an elongated protrusion 64a on its outer peripheral surface. The elongated protrusion 64 a protrudes to the inner peripheral surface of the toner container holder 42 . The toner container holder 42 has an elongated groove 42b on its inner peripheral surface. The outer cylinder 64 is supported by the toner cartridge holder 42 by fitting the protrusion 64a into the elongated groove 42b. Therefore, the outer cylinder 64 is secured relative to the toner container holder 42 in a fixed manner and cannot rotate relative to the outer cylinder 64 .

The handle 62 is integrally formed with the inner cylinder 63 . When the user operates the handle 62 to move the handle up or down, the inner cylinder 63 can rotate around its central axis relative to the outer cylinder 64 .

As shown in FIG. 12A , a pair of guide rails 42 c are provided on the inner peripheral surface of the toner container holder 42 . A shutter 48 made of metal is slidably mounted on a pair of guide rails 42c at a pair of opposite ends thereof. The shutter 48 has a rectangular shape in which the long side is located in the axial direction of the toner container holder 42 . The shutter 48 can move upward from the opening 42a to reveal the opening of the opening 42a in the closed position where the shutter 48 closes the opening 42a as shown in FIG. 12A along the circumferential surface of the cylindrical toner cartridge holder 42. Move between the positions.

Two pairs of protrusions 63 a are provided on the outer peripheral surface of the inner cylinder 63 . As the shutter 48 is sandwiched between the two pairs of protrusions 63 a, the two pairs of protrusions 63 a are separated from each other in the circumferential direction of the inner cylinder 63 . The two protrusions 63 a constituting each pair are separated from each other in the axial direction of the inner cylinder 63 and face two opposite longitudinal ends of the shutter 48 . As the inner cylinder 63 rotates, the two pairs of projections 63 a move the shutter 48 while holding the shutter 48 therebetween in the circumferential direction along the inner peripheral surface of the toner container holder 42 . When the handle 62 is rotated to the disconnected position shown in FIG. 6, the shutter 48 closes the opening 42a as shown in FIG. 12A.

The elongated groove 42b is located on the inner peripheral surface of the toner container holder 42 at a position below the shutter 48, even in the case where the shutter 48 is moved to its lowest position shown in FIG. 12A to completely close the opening 42a. Also be unlikely to make valve 48 overlap.

The opening 42 a has a rectangular shape in which the long side is located in the axial direction of the toner container holder 42 . A rectangular frame-shaped sponge member 49 is bonded to the inner peripheral surface of the toner container holder 42 around the opening 42a.

A pair of engagement pieces 63 c are formed integrally with the inner cylinder 63 on the outer peripheral surface of the inner cylinder 63 . The pair of engaging pieces 63c is provided on the inner cylinder 63 at such a position that each engaging piece 63c can engage with the pair of guide rails 42c when the handle 62 of the inner cylinder 63 is in the connected position shown in FIG. 4 . It should be noted that each guide rail 42c has an L-shaped cross section, and each engaging member 63c has a cross-sectional shape capable of engaging with the L-shaped cross section of the corresponding guide rail 42c.

The outer cylinder 64 is formed with an opening 64b having the same shape as the opening 42a. The opening 64b is provided in the outer cylinder 64 at such a position that when the outer cylinder 64 is mounted in the toner cartridge holder 42 by fitting the elongated protrusion 64a into the elongated groove 42b, the opening 63b will be This position faces the opening 42a. A sponge member 65 having the same shape as the sponge member 49 is bonded to the outer peripheral surface of the outer cylinder 64 around the opening 64b.

The inner cylinder 63 is formed with an opening 63b having the same shape as the opening 64b. As shown in FIG. 12B, when the handle 62 is in the disconnected position in FIG. 6, the openings 64b and 63b do not overlap each other. This structure ensures that toner does not flow out of the toner container 60 when the toner container 60 is removed from the developing cartridge 40 as shown in FIG. 7 .

The handle 62 of the toner container 60 is rotated downward from the disconnected position shown in FIG. 6 to the connected position shown in FIG. 4 while keeping the protrusion 64a engaged with the elongated groove 42b. As a result, the openings 64b and 63b overlap each other as shown in FIG. 12D, and the projection 63a pushes the shutter 48 from the opening 42a as shown in FIG. 12C. As a result, the inner side of the inner cylinder 63 and the inner side of the developing portion 40 a of the developing cartridge 40 are in fluid communication. Thus toner can be supplied from the toner container 60 to the developing portion 40 a in the developing cartridge 40 .

At this time, both the sponge members 49 and 65 are in close contact with each other, and each engaging piece 63c is engaged with each guide rail 42c. Therefore, the openings 64b and 42a are hermetically sealed over their entire peripheries, not allowing the toner to flow out. When the engaging member 63c is thus engaged with the guide rail 42c, the developing cartridge 40 and the toner cartridge 60 are connected to each other as shown in FIG. Therefore, the cartridges 40 and 60 can be removed and inserted with respect to the photosensitive drum cartridge 20 as an integral unit as shown in FIG. 8 . Thus, the cartridges 40 and 60 can be removed and inserted relative to the main body of the laser printer 1 as an integral unit as shown in FIG. 8 .

The handle 62 can be operated to rotate the inner cylinder 63 to release the engagement members 63c from the guide rails 42c. Thus, the developing cartridge 40 and the toner cartridge 60 are detachably connected to each other. Thus, only the toner cartridge 60 can be removed from the laser printer 1 as shown in FIG. 7 .

As shown in FIGS. 12A and 13 , a gear 53 is mounted on the inner side of the right side end wall of the toner container holder 42 . When the toner container 60 is placed in the toner container holder 42, the gear 53 meshes with the gear 61b.

As shown in FIG. 15 , an upper auger roller 43 and a lower auger roller 44 protrude outward from the right side wall of the developing cartridge 40 . As shown in FIG. 13, gears 43a and 44a are attached to the right end portions of the upper screw conveyor roller 43 and the lower screw conveyor roller 44, respectively. Thus, the gears 43 a and 44 a are located on the outer surface of the right side wall of the developing cartridge 40 . The gears 43a and 44a rotate integrally with the upper screw conveyor roller 43 and the lower screw conveyor roller 44, respectively. The gear 53 meshes with both the gears 43a and 44a. It should be noted that components disposed outside the developing cartridge 40 such as the gears 43a and 44a are not shown in FIG. 15 for convenience of explanation.

As shown in FIG. 10 , the drive shaft 161 is provided on the inner surface of the left side wall in the main body of the printer 1 . The drive shaft 161 forms a so-called drive connection with the rotational shaft 61a of the agitator 61 shown in FIG. 11 . Specifically, the drive shaft 161 has a plate-shaped protrusion 161a at its shaft tip. The rotating shaft 61a has a hollow cylindrical portion at the top end of the shaft on the left side thereof, and a pair of protrusions 61c provided in the hollow cylindrical portion. The pair of protrusions 61 c may engage with the plate-shaped protrusion 161 a of the drive shaft 161 . In this way, the drive shaft 161 can be adapted to the rotating shaft 61a.

When the driving force is transmitted from the driving shaft 161 to the rotating shaft 61a, the agitator 61 is rotated. The driving force is transmitted from the gear 61b to the gear 53, and then from the gear 53 to the gears 43a and 44a. As a result, the screw conveyor rollers 43 and 44 rotate.

As shown in FIG. 10 , the gear 171 is fastened in a fixed manner with respect to the rotating shaft of the developing motor 170 and rotates integrally with the rotating shaft of the developing motor 170 . The provided gear 172 meshes with the gear 171 .

An electromagnetic clutch 275 provided as shown in FIG. 16 connects and disconnects the drive shaft 151 with respect to the gear 172 . When the electromagnetic clutch 275 is in the state of connecting the drive shaft 151 and the gear 172 , the drive shaft 151 and the gear 172 rotate integrally. When the electromagnetic clutch 275 is in a disengaged state that disconnects the drive shaft 151 from the gear 172 , even if the gear 172 rotates, the drive shaft 151 does not rotate.

The gear 174 is fastened with respect to the drive shaft 161 in a fixed manner, and the gear 174 rotates integrally with the drive shaft 161 . Gear 173 is provided to mesh with both gears 172 and 174 . In this way, the gear 174 is meshed with the gear 172 through the gear 173 .

When the electromagnetic clutch 275 is switched to the connected state, the driving force of the developing motor 170 is output from both the drive shafts 151 and 161 to the cartridges 40 and 60 . As a result, the developing roller 41, the toner supply roller 45, the upper auger roller 43, the lower auger roller 44, and the agitator 61 are driven. On the other hand, when the electromagnetic clutch 275 is switched to the disengaged state, the driving force of the developing motor 170 is output to the drive shaft 161 only. In this case, the upper screw conveying roller 43, the lower screw conveying roller 44, and the agitator 61 are driven, while the developing roller 41 and the toner supply roller 45 are still in a stopped state.

The driving shafts 151 and 161 are provided on the left side wall in the main body of the laser printer 1, and both can be extended and retracted together. Specifically, the drive shafts 151 and 161 are connected to a link mechanism (not shown), and protrude when the cover 4 is closed, and retract when the cover 4 is opened. When the cover 4 is opened, the drive shafts 151 and 161 are disengaged from the drive shaft 51 and the rotary shaft 61a, respectively. In this way, the photosensitive drum cartridge 20 , the developing cartridge 40 , and the toner cartridge 60 can be removed from the main body of the laser printer 1 . On the other hand, when the cover 4 is closed, the drive shafts 151 and 161 are engaged with the drive shaft 51 and the rotary shaft 61a, respectively. As a result, the above-mentioned components can be driven.

Next, the agitator 61 will be described in detail with reference to FIG. 14 .

The agitator 61 is made of flexible resin such as ABS resin, and is constituted by the following parts integrally formed with each other. Specifically, the agitator 61 includes a shaft 61a, a gear 61b (FIG. 13), a blade member 61d, a flexible film member 61e, and a pair of blade support members 61f, which are integrally formed with each other. The blade member 61d is fastened to the rotating shaft 61a. The membrane member 61e is fastened to the blade member 61d. The blade holder 61f is fastened to the rotating shaft 61a.

The blade holders 61e protrude from a pair of opposite shaft ends (left and right side shaft ends) of the rotation shaft 61a in directions opposite to the direction in which the blades 61d protrude, respectively. As will be described below, a pair of toner amount detection windows 63d are provided on a pair of opposite side end walls (left and right end walls) of the inner cylindrical body 63 . One wiper member 67 is fixed relative to each wiper support member 61f in elastic contact with the inner surface of the corresponding end wall (left or right end wall) of the inner cylinder 63 so as to be able to wipe the corresponding end wall The toner amount detection window 63d on the top.

It should be noted that the pair of toner amount detection windows 63d are formed at the rear lower portions of the left and right end walls of the inner cylinder 63, respectively. The pair of detection windows 63d are opposed to each other. As shown in FIGS. 11 and 13, the toner container holder 42 is formed with a pair of circular light-transmitting through holes 42d. The pair of circular light-transmitting through holes 42d are respectively formed through the left and right side end walls of the toner container holder 42, and are opposed to the toner amount detection window 63d.

As shown in FIG. 15, the upper auger roller 43 and the lower auger roller 44 have helical blades 43b and 44b, respectively. When the agitator 61 is driven, as shown by the arrow in the figure, the lower screw conveying roller 44 conveys the toner from the opening 42a to the left and right sides of the developing cartridge 40, while the upper spiral conveying roller 43 conveys the toner from the developing cartridge 40 The left and right sides are transported back to the middle of the box 40. Therefore, the toner can be recovered from the left and right sides of the developing cartridge 40 to the center thereof, and returned to the toner container 60 through the opening 42a.

Therefore, the upper screw conveying roller 43 , the lower screw conveying roller 44 , and the agitator 61 circulate the toner not only between the developing cartridge 40 and the toner cartridge 60 but also within the developing cartridge 40 . This prevents the degraded toner from agglomerating, forming hard lumps, and firmly adhering thereto at specific locations, thereby maintaining the fluidity of the toner.

As shown in FIGS. 14 and 15 , the spacer 55 is disposed between the upper screw conveying roller 43 and the lower screw conveying roller 44 in the developing cartridge 40 . This partition 55 contributes to the smooth conveyance of toner.

As shown in FIGS. 12B and 14 , a pair of spring seats 66 are provided on the outer surface of the inner cylinder 63 . The spring seat 66 is located slightly higher than the left and right ends of the handle 62 . Each spring seat 66 has a concave portion in the middle portion of the cylindrical body 63 in the circumferential direction. As shown in FIG. 2 , a pair of pushing pieces 71 protrude from the back of the cover 4 . Each pushing piece 71 is urged in its protruding direction by a spring (not shown) installed in the pushing piece 71 . When the cover 4 is closed, the spring seat 66 receives the pushing force of the pushing member 71 . This thrust securely holds the cartridges 20, 40, and 60 in their installed positions.

An intervening member 72 also protrudes from the back of the cover 4 at a position between the pair of pushing pieces 71 . The intervening member 72 interferes with the handle 62 unless the handle 62 is placed in the connected position shown in FIG. 4 . Therefore, the lid 4 cannot be closed until the handle 62 is properly placed in the connected position.

The laser printer 1 has a control system, which will be described below with reference to FIG. 16 .

As shown in FIG. 16 , the laser printer 1 has a cap sensor 198 and an end sensor 199 . The lid sensor 198 is, for example, a limit switch, and detects whether the lid 4 is opened or closed. The end sensor 199 is, for example, an optical coupler, and optically detects whether there is toner in the toner cartridge 60 through the toner amount detection window 63d and the light-transmitting through hole 42d. In this example, the end sensor 199 includes a light emitting element 199a and a light receiving element (not shown). As shown in FIG. 10 , the light-emitting element 199 a is provided on the inner surface of the left side wall in the main body of the laser printer 1 . Although not shown, a light receiving element is provided on the inner surface of the right side wall in the main body of the laser printer 1 .

The control unit 200 of the laser printer 1 is a known type of microcomputer including a CPU 201 , a ROM 202 , a RAM 203 , an I/O 204 , and a bus 205 . The bus 205 connects the components 201, 202, 203, and 204 to each other. The I/O port 204 receives signals output by the lid sensor 198 and the end sensor 199 . The I/O port 204 is connected to the scanning unit 90 , the photosensitive drum motor 122 , the developing motor 170 , and the electromagnetic clutch 275 through drive circuits 211 , 212 , 213 , and 214 , respectively. Mechanisms of known types such as an operation panel and a buzzer are also connected to the I/O port 204 .

FIG. 17 is a flowchart illustrating processing executed by the CPU 201 according to a program stored in the ROM 202 according to the present embodiment. This process is repeatedly executed at a predetermined timing after the laser printer 1 is powered on.

When this process is started, first the CPU 201 determines in S1 whether the toner cartridge 60 is empty based on the detection signal of the end sensor 199 . In other words, the CPU 201 determines whether the toner has been consumed so much that light continues to pass through the light-transmitting through hole 42d for a relatively long time. It should be noted that even if there is a sufficient amount of toner in the toner container 60 , light can pass through the light-transmitting through hole 42 d because the agitator 61 agitates the toner in the inner cylinder 63 . However, as the amount of toner in the cartridge 60 decreases, the length of time that light continues to pass through the light-transmitting through-hole 42d increases. Therefore, the CPU 201 determines whether the toner cartridge 60 is used up by detecting the length of time that light continues to pass through the light-transmitting through hole 42d.

If the toner cartridge 60 is not used up in S1 (No in S1), the process proceeds to S2. Normal or normal processing is performed in S2. For example, an image forming job is performed based on data input to the laser printer 1 . Then, the process returns from S2 to S1. Specifically, the usual processing is continued until it is determined in S1 that the toner cartridge 60 is used up.

It should be noted that when the image forming job is performed in the normal processing of S2, the electromagnetic clutch 275 is switched to the connected state, and the developing motor 170 is driven, thereby driving the developing roller 41, the toner supply roller 45, the upper screw conveyor roller 43, the lower screw conveyor Conveying roller 44, and agitator 61. It should be noted that the photosensitive drum motor 122 is also driven to rotate the photosensitive drum 21 .

On the other hand, when the toner cartridge 60 is used up (YES in S1), the process proceeds to S3. In S3, the display provided on the operation panel displays a message, and the buzzer on the laser printer 1 sounds an alarm to inform the user that the cartridge 60 is used up. When the toner end is detected, the laser printer 1 tends to form an image on paper at this time. In view of this situation, after the image forming job currently being executed is completed, the image forming process is prohibited in S4.

In S6 the CPU 201 determines whether the cover 4 is open. The process of S6 is repeated until the cover sensor 198 detects that the user opens the cover 4 to replace the toner cartridge 60 with a new one in response to the message or warning issued in S3.

When the cover 4 is opened (YES in S6), the process proceeds to S7. In S7 the CPU 201 determines whether or not the cover 4 has been closed by the user. The process of S7 is repeated until the user closes the cover 4 . When the cover 4 is still open, the user replaces the toner cartridge 60 with a new one in most cases. Once the cover 4 is closed (YES in S7 ), the CPU 201 determines that the user has set a new toner cartridge 60 in the laser printer 1 . Then the process goes to S8.

The electromagnetic clutch 275 is switched to the disengaged state in S8, and then the developing motor 170 starts to be driven. The upper screw conveying roller 43, the lower screw conveying roller 44, and the agitator 61 are driven for a predetermined period of time while the developing roller 41 and the toner supply roller 45 are still in a stopped state. Therefore, the old toner remaining in the developing cartridge 40 and the new toner stored in the new toner cartridge 60 are circulated, thereby being mixed with each other. When the predetermined time elapses, in S9 the image formation prohibition state set in S4 is released for the laser printer 1 . Then the process returns to S1.

In the above steps, after the new toner cartridge 60 is connected to the developer cartridge 40, the upper screw conveyor roller 43, the lower screw conveyor roller 44, and the agitator 61 are driven for a predetermined period of time to mix the old and new toner. Since the developing roller 41 and the toner supply roller 45 are stopped for a predetermined period of time, the toner is not rubbed to be charged. Prevents unwanted print fogging.

Specifically, the laser printer 1 uses a non-magnetic one-component toner for triboelectrification. Non-magnetic one-component toners, especially styrene-propylene polymerized toners, become less rechargeable as the toner performance degrades. Specifically, old toner has little rechargeability, and new toner has greater rechargeability. If the old and new toners are mixed with each other and charged by friction, the toners are not charged with the same polarity. New toner is positively charged, while old toner is negatively charged. If a large amount of positively charged new toner exists near the developing roller 41, the new toner mainly adheres to the developing roller 41 due to the force of the image. Therefore, even if old toner charged with negative polarity exists near the developing roller 41, no printing fogging occurs.

Conversely, if new toner is added to the old toner that has been negatively charged and exists in large quantities near the developing roller 41, the old toner will mainly adhere to the developing roller 41 due to the force of the image, thereby unavoidable. There is a phenomenon of printing fogging.

According to this embodiment, the process of S8 is executed after the toner cartridge 60 is replaced with a new one. New toner and old toner can be mixed with each other without frictional electrification. After a large amount of new toner and a small amount of old toner are sufficiently uniformly mixed, the developing roller 41 and the toner supply roller 45 are started to be driven to charge the toner by friction. In other words, frictional electrification is prevented from occurring when a small amount of new toner and a large amount of old toner (ie, degraded toner) exist near the developing roller 41 . Thus, printing fogging can be prevented from occurring.

It should be noted that if the developing motor 170 is driven at a higher speed in S8 than in the normal image forming operation (S2), the new toner and old toner can be mixed more rapidly. In this case, after the toner cartridge 60 is replaced with a new one, the normal image forming operation can be quickly started.

Since the developing roller 41 and the toner supply roller 45 are arranged to be in contact with each other, once the rollers 41 and 45 are driven to rotate, the particles of new toner and old toner are in sliding contact between the rollers 41 and 45. movement and electrification by friction. However, according to the present embodiment, the developing roller 41 and the toner supply roller 45 are in a stopped state for a predetermined period of time during the process of S8. Thus, for the predetermined period of time, frictional electrification can be reliably prevented.

Since the agitator 61 and the auger rollers 43 and 44 are all driven in S8, the toner can be smoothly circulated.

The more chargeable the toner is, the more likely the print will fog. The above advantages of this embodiment are prominent when using the styrene-propylene polymerized toner because the styrene-propylene polymerized toner has high chargeability. Since the polymerized toner has high fluidity, even if the developing roller 41 is in a stopped state in S8, there is almost no influence on the recycling of the toner. By using the polymerized toner, the influence of stopping the developing roller 41 in S8 on the toner recycling can be reduced.

When it is found that the performance of the developing roller 41 is too low, it can be replaced with a new developing cartridge 40 . This increases maintenance efficiency. Likewise, if the photosensitive drum 21 is found to be degraded in performance, it can be replaced with a new photosensitive drum cartridge 20 . This likewise increases maintenance efficiency.

It should be noted that when the toner container 60 is disconnected from the developer cartridge 40, no driving force is transmitted to the upper screw conveyor roller 43 or the lower screw conveyor roller 44. Once the upper screw conveying roller 43 and the lower screw conveying roller 44 are driven in a state disconnected from the toner cartridge 60 , the toner may overflow the developing cartridge 40 . Since neither the upper screw conveying roller 43 nor the lower screw conveying roller 44 is driven, and this is the case unless or until the toner cartridge 60 is connected to the developing cartridge 40, the overflow of the toner from the developing cartridge 40 is reliably prevented as described above.

Specifically, when the toner cartridge 60 is connected to the developing cartridge 40, the driving force is input from the drive shaft 161 on the main body of the laser printer 1 to the left side end of the rotating shaft 61 of the agitator 61 through the driving connection. Then, the driving force is output from the rotating shaft 61 of the agitator 61 to the screw conveying rollers 43 and 44 through the gear 61b located on the right shaft end of the rotating shaft 61a. Thereby, the conveying screw rollers 43 and 44 are driven. When the toner cartridge 60 is disconnected from the developing cartridge 40, the rotary shaft 61a having the driving force input portion (left shaft end) and the driving force output portion (gear 61b) is also removed. The driving force can no longer be transmitted to the screw conveyor rollers 43 and 44 . This prevents the conveying screw rollers 43 and 44 from operating in a state where the toner cartridge 60 is disconnected from the developing cartridge 40 . This prevents toner from overflowing the developing cartridge 40 .

As long as the toner cartridge 60 is connected to the developing cartridge 40, the screw conveying rollers 43 and 44 and the agitator 60 cooperate with each other. Therefore, the laser printer 1 can be easily controlled.

The left shaft end of the rotating shaft 61 a is connected to the driving shaft 161 to receive the driving force, and the gear 61 b is disposed on the right shaft end of the rotating shaft 61 a to output the driving force to the screw conveying rollers 43 and 44 . Therefore, the portion receiving the driving force and the portion outputting the driving force are disposed on opposite sides of the toner cartridge 60 . It is then possible to easily design a drive system such as a gear arrangement located near the drive force input portion and the drive force output portion. It is thereby possible to easily miniaturize the toner cartridge 60, the developing cartridge 40, and the laser printer 1.

Specifically, in the developing cartridge 40, the developing roller 41 and the screw conveying rollers 43 and 44 must be arranged in close proximity to each other. Furthermore, the toner supply roller 45 must be arranged in the developing cartridge 40 . Therefore, according to this embodiment, one of the driving mechanisms is provided on one side (left side) of the developing cartridge 40 to drive the developing roller 41 and the toner supply roller 45, and the other driving mechanism is provided on the other side of the developing cartridge 40. (right side) to drive the auger rollers 43 and 44. Thus, the driving force is transmitted from one side (left side) of the toner container 60 to the other side (right side) thereof through the toner container 60 (rotation shaft 61a). Therefore, the developing roller 41 , the toner supply roller 45 , and the screw conveying rollers 43 and 44 can all be driven by a single developing motor 170 . It is therefore not necessary to install one but two motors on each side of the developing cartridge 40 . Therefore, the laser printer 1 can be downsized.

The toner is circulated using the screw conveying roller pair 43 and 44 having a simple configuration. This contributes to reducing the manufacturing cost of the laser printer 1 .

[Modification of the first embodiment]

In the above-mentioned first embodiment, when the new toner container 60 is connected to the developing cartridge 40, the new toner is mixed with the old toner in S8, and the developing roller 41 and the toner supply roller 45 are stopped at the same time. Instead, according to a modification of the first embodiment, only the developing roller 41 is stopped while new toner is mixed with old toner, as explained below.

18A and 18B, the gear 51b integrally rotating with the drive shaft 51 meshes with the gear 41a integrally rotating with the developing roller 41, but not meshes with the gear 45a integrally rotating with the toner supply roller 45. The gear 61g is fastened to the left end portion of the rotating shaft 61a of the agitator 61, and rotates integrally with the rotating shaft 61a. The gear 61g is located on the outer side of the left end wall of the inner cylinder 63 . Gears 68 and 69 are provided on the inner surface of the left side wall of the developing cartridge 40, and mesh with each other. The gear 69 meshes with the gear 45a. When the toner cartridge 60 is installed in the developing cartridge 40, the gear 68 is meshed with the gear 61g. Therefore, when the driving force is transmitted from the driving shaft 151 to the driving shaft 51, the developing roller 41 can be rotated. When the driving force is transmitted from the drive shaft 161 to the rotary shaft 61a, the toner supply roller 45, the agitator 61, the upper auger roller 43, and the lower auger roller 44 can be rotated.

As shown in FIG. 19, the toner supply roller 45 is separated from the developing roller 41 and is in such a position that it does not come into contact with the developing roller 41. As shown in FIG. Therefore, even if the toner supply roller 45, the agitator 61, the upper screw conveying roller 43, and the lower screw conveying roller 44 are all rotated while only the developing roller 41 is still in a stopped state, the toner will flow between the developing roller 41 and the toner supply. Roller 45 also will not be subject to friction when moving between the two. Therefore, the toner will not be charged by friction. Therefore, this modified example can obtain the same advantages as those of the first embodiment when the laser printer 1 performs the same processing as described above with reference to FIG. 17 . Specifically, when the electromagnetic clutch 275 is switched to the disengaged state and the developing motor 170 is driven in S8, the toner supply roller 45, the upper screw conveying roller 43, the lower screw conveying roller 44, and the agitator 61 are driven for a predetermined amount. time, while the developing roller 41 is still in a stopped state. For this predetermined time, the new toner and the old toner can be uniformly mixed without being charged by friction.

Since the developing roller 41 and the toner supply roller 45 are arranged out of contact with each other, toner particles no longer move between the respective rollers 41 and 45 in a frictionally electrified sliding contact. Even if the upper screw conveying roller 43, the lower screw conveying roller 44, and the agitator 61 are driven for a predetermined time while the toner supply roller 45 rotates, since the rotation of the developing roller 41 is stopped, it is possible to prevent the toner from being rotated for the predetermined time. During friction electrification.

[Second embodiment]

Next, a second embodiment will be described with reference to FIGS. 20-27.

The second embodiment differs from the first embodiment in the driving manner of the components in the developing cartridge 40 and the toner cartridge 60 .

The configurations of the developing cartridge 40 and the toner cartridge 60 are generally the same as those of the first embodiment, but differ in the following respects:

The left shaft end of the rotating shaft 61a does not constitute the configuration of the above-mentioned driving connection. The gear 61b is not disposed on the right shaft end of the rotating shaft 61a. Instead, as shown in FIG. 20, the gear 61h is integrally formed with the rotary shaft 61a at its left shaft end. The gear 61h is located on the outer side of the left end wall of the inner cylinder 63 .

A gear 153 is provided on the inner surface of the left end wall of the toner container holder 42 . The gear 153 meshes with the gear 51b. When the toner cartridge 60 is installed in the developing cartridge 40, the gear 153 is at a position opposite to the gear 61h. Thus, when the toner container 60 is connected to the developing cartridge 40, the gear 153 is meshed with the gear 61h. Accordingly, the driving force is transmitted from the drive shaft 51 to the rotary shaft 61a of the agitator 61 through the gears 51b, 153, and 61h.

As shown in FIG. 21 , the drive shaft 54 is provided on the right side of the toner container holder 42 . As shown in FIG. 25 , the drive shaft 154 is provided on the inner surface of the right side wall in the main body of the laser printer 1 . The drive shafts 54 and 154 form a so-called drive connection. The drive shaft 154 has a flat plate-like protrusion 154a on its shaft tip. The drive shaft 54 has a hollow cylindrical portion on its shaft tip. The drive shaft 54 has two protrusions 54a that can engage with the plate-shaped protrusion 154a. The drive shaft 154 can thus be adapted to the drive shaft 54 .

The gear 54 b is fastened with respect to the drive shaft 54 and is located on the inner surface of the right side end wall of the toner container holder 42 . The gear 54b meshes with the gears 43a and 44a fastened with respect to the upper and lower screw conveyor rollers 43 and 44, respectively.

Therefore, when the driving shaft 154 transmits the driving force to the driving shaft 54, the upper and lower screw conveying rollers 43 and 44 may be rotated.

Note that the toner container 60 is connected and disconnected from the developing cartridge 40 in the same manner as in the first embodiment. Specifically, FIGS. 22A and 22B show a state in which the toner cartridge 60 is disconnected from the developing cartridge 40 according to the second embodiment, that is, the handle 62 of the cartridge 60 has been rotated upward to the disengaged position as in FIG. 6 . 22C and 22D show the state in which the toner cartridge 60 is connected to the developing cartridge 40 according to the second embodiment, that is, the handle 62 of the cartridge 60 has been rotated downward to the connected position as in FIG. 4 . 22A-22D correspond to FIGS. 12A-12D of the first embodiment, respectively.

The configuration of the laser printer 1 of the second embodiment is generally the same as that of the first embodiment, but differs in the following respects:

As shown in FIG. 23, according to the second embodiment, no drive shaft 161 is provided on the left side wall in the main body of the laser printer 1. As shown in FIG.

As shown in FIG. 24 , according to the present embodiment, the gear 151b is provided to rotate integrally with the drive shaft 151 . The gear 151b meshes with the gear 171 through the gear 272 . As in the first embodiment, the gear 171 rotates integrally with the developing motor 170 . Thus, when the developing motor 170 is driven, the driving shaft 51 drives the developing roller 41, the toner supply roller 45, and the agitator 61.

The drive system shown in FIG. 25 is provided on the inner surface of the right side wall in the main body of the laser printer 1 . This drive system is located opposite the drive system shown in FIG. 24 . As shown in FIG. 25, the right side wall in the main body of the laser printer 1 also has guide grooves 121 formed on its inner surface. The guide groove 121 guides the rotation shaft 21 a of the photosensitive drum 21 . The driving shaft 154 is disposed in the middle of the guide groove 121 . The gear 154b is provided to rotate integrally with the drive shaft 154 . The return motor 175 is provided on the right side wall in the main body of the laser printer 1 . The gear 176 is provided to rotate integrally with the rotation shaft of the return motor 175 . Gear 154b meshes with gear 176 . Thus, when the return motor 175 is driven, the rotary shaft 54 can simultaneously drive the upper and lower screw conveyor rollers 43 and 44 .

It should be noted that, like the drive shafts 151 and 161 in the first embodiment, the drive shafts 151 and 154 can be extended and retracted. The rotating shafts 151 and 154 are connected with a link mechanism (not shown), so that the rotating shafts can be extended when the cover 4 is closed, and can be retracted when the cover 4 is opened. When the cover 4 is opened, the shafts 151 and 154 are retracted to disengage from the drive shafts 51 and 54, respectively. Therefore, the photosensitive drum cartridge 20, the developing cartridge 40, and the toner cartridge 60 can be removed from the laser printer 1 main body. When the cover 4 is closed, the drive shafts 151 and 154 are extended to engage with the drive shafts 51 and 54 . In this case, the above-mentioned components can be driven.

As shown in FIG. 25 , a light receiving element 199 b is provided on the inner surface of the right side wall in the main body of the laser printer 1 . The end sensor 199 is constituted by the light emitting element 199a and the light receiving element 199b shown in FIGS. 23 and 24 .

As shown in Figure 26, the control system of the laser printer 1 of this embodiment is generally the same as that of the first embodiment (Figure 16), except that the return motor 175 is provided instead of the electromagnetic clutch 275, and the ROM 202 stores its flow chart as shown in FIG. The procedure shown in FIG. 27 is not the procedure of FIG. 17 .

Next, the processing executed by the CPU 201 of the control unit 200 according to the program stored in the ROM 202 according to the present embodiment will be described with reference to FIG. 26 .

Similar to the first embodiment, this process is repeatedly executed at a predetermined timing after the power of the laser printer 1 is turned on. When this process is started, the process of S11 is executed first. It should be noted that the processing of S11-S14 is the same as that of S1-S4 of the first embodiment.

After prohibition of image formation in S14, the routine proceeds to S15.

Recovery control is started in S15. Specifically, the return motor 175 is driven while the developing motor 170 is still stopped. As a result, the agitator 61 stops supplying toner from the toner container 60, and the developing roller 41 and the toner supply roller 45 stop rotating. On the other hand, the upper and lower screw conveyor rollers 43 and 44 are driven. The lower spiral conveying roller 44 conveys the toner in the developing cartridge 40 to the left and right sides, and then the upper spiral conveying roller 43 conveys the toner to the middle. The toner returns to the toner container 60 through the opening 42a. As an independent routine, this recovery control is continuously performed for a long period of time sufficient for the toner in the developing cartridge 40 to be completely recovered to the toner container 60 . This recovery control is automatically stopped when the toner is completely recovered. Specifically, the return motor 175 is stopped, while the developing motor 170 is still in a stopped state.

After the recovery control is started in S16, the CPU 201 judges whether or not the cover 4 is open. If the user ignores the information or warning sent in S13 (in the negative situation in S16), the process of S16 is repeated until the cover sensor 198 detects that the user opens the cover 4 and replaces it with a new toner cartridge 60 .

When the cover 4 is opened (positive case of S16), the recovery control is prohibited in S17. Then, in S18, the CPU 201 judges whether or not the recovery control is completed. If the recovery control has not been completed (in the negative case of S18), the process proceeds to S19. In S19, an alarm is issued to notify the user that the toner cartridge 60 cannot be replaced. Then, in S20, CPU 201 determines whether or not the user has closed cover 4 in response to the warning. If the user has not yet closed the cover 4 (negative case in S20 ), the process of S20 is repeatedly executed until the user closes the cover 4 . When the user closes the cover 4 (YES in S20), the process returns to S15, and collection control is executed.

If the cover 4 is opened after the recovery control has been completed (YES in S18), the processing proceeds to S21. In S21, CPU 201 judges whether or not cover 4 is closed. The process of S21 is repeated until the cover 4 is closed. Usually, the user replaces the toner cartridge 60 with a new one during the repetition of the process of S21. When the user closes the cover 4 (YES in S21), the processing proceeds to S22. In S22, the agitator 61 is driven by a predetermined amount to fill the developing cartridge 40 with toner. For example, the agitator 61 is driven for a predetermined period of time. Then, the process proceeds to S23, and the image formation prohibition state set in S14 is released for the laser printer 1 . Then the process returns to S11.

Therefore, in this embodiment, if the toner cartridge 60 is used up (Yes in S11), the toner in the developing cartridge 40 is automatically recovered into the toner cartridge 60 (in S15). After the toner has been collected into the toner cartridge 60 , the toner cartridge 60 is replaced with a new toner cartridge 60 .

Specifically, when the recycling control has been completed (Yes in S18), only a small amount of toner (ie, old toner with degraded performance) remains in the developing cartridge 40 . In this state, the toner container 60 can be replaced with a new one. Therefore, it is possible to prevent a large amount of old toner from being mixed with new toner when new toner is supplied from the new toner container 60 . Therefore, printing fogging can also be avoided in this embodiment.

As the toner is circulated in the developing cartridge 40 by the screw conveying rollers 43 and 44 in S15 , the toner can be homogenized and fully returned to the toner cartridge 60 .

The developing roller 41 conveys toner to the photosensitive drum 21 . Therefore, by stopping the developing roller 41 in S15, the toner can be returned to the toner container 60 more fully.

In the above description, after the toner container 60 is replaced with a new one (Yes in S21), the agitator 61 is driven by a predetermined amount (for example, for a predetermined period of time) in S22. Then, the image formation prohibited state is canceled in S23. This brings about the following advantages.

Although it is detected that the toner is used up, the user may mistakenly reinstall the old toner cartridge 60 on the developing cartridge 40 instead of replacing it with a new toner cartridge 60 . In this case, a large amount of toner is recovered into the toner container 60 in S15, so that false detection may occur in S11. However, according to this embodiment, after the toner container 60 is replaced with a certain toner container (Yes in S21), the process returns to S11 after the agitator 61 is driven by a predetermined amount (for example, for a predetermined period of time) in S22. Thus, such false detection can be prevented from occurring.

In addition, since the process returns to S11 after the agitator 61 is driven by a predetermined amount (for example, for a predetermined period of time) in S22 after the toner container 60 is replaced with a certain toner container (Yes in S21), it is ensured that the total The image forming job is performed in a state where the developing cartridge 40 is filled with a sufficient amount of toner. It is thus possible to prevent the image from being too light.

It should be noted that in order to prevent misdetection, the size of the aforementioned predetermined amount (eg, the length of the predetermined time period) may be set to an appropriate value in advance according to the configuration of the toner container 60 and the agitator 61 .

Although the present invention has been specifically described with reference to the above-mentioned embodiments, it is obvious that various changes and modifications can be made by those skilled in the art without departing from the essence of the present invention.

For example, in the above description, whether to replace the toner cartridge 60 with a new one is determined by detecting the amount of toner remaining in the toner cartridge 60 . Alternatively, it may be determined whether toner cartridge 60 should be replaced by detecting how many pages have been printed.

In the above description, it is determined by the cover sensor 198 whether the toner container 60 has been replaced. However, whether the toner cartridge 60 has been replaced can be determined by the end sensor 199 . Alternatively, the replacement of the toner cartridge 60 may be detected by using an IC label attached to the toner cartridge 60 and an IC label reader provided on the laser printer 1 .

The laser printer 1 can be modified into various types of electrophotography-type image forming apparatuses such as copying devices, facsimile devices, and color laser printers. The photosensitive drum 21 may be modified into a photoelectric belt. A non-photosensitive latent electrostatic image bearing body may be provided instead of the photosensitive drum 21 . The toner image may be transferred to a recording medium using an intermediate transfer belt.

In the above description, since the photosensitive drum cartridge 20 and the developing cartridge 40 are detachably installed in the main body of the laser printer 1, they can be replaced with new ones when necessary. This contributes to easy maintenance of the laser printer 1 . However, the photosensitive drum cartridge 20 and the developing cartridge 40 can be secured in the main body of the laser printer 1 in a fixed manner.

In the above description, the photosensitive drum cartridge 20 and the developing cartridge 40 are detachably connected to each other. This contributes to easy maintenance of the photosensitive drum cartridge 20 and the developing cartridge 40 . However, the photosensitive drum cartridge 20 and the developing cartridge 40 may be formed integrally with each other in a process cartridge. The photosensitive drum cartridge 20 and the developing cartridge 40 may not be disconnected from each other.

In the first and second embodiments described above, the styrene-propylene polymerized toner was used. However, any polymerized toner may be used instead of the styrene-propylene polymerized toner. Non-polymerizable toners can also be used.

Claims (31)

1. an image forming apparatus is characterized in that, comprising:

Form the electrostatic latent image load bearing component of electrostatic latent image on the surface that is had;

Deposit the toner cartridge of toner;

Toner is fed on the surface of electrostatic latent image load bearing component from toner cartridge, thereby latent electrostatic image developing is the developing parts of toner image;

With the transfer member of toner image on from the surface transfer of electrostatic latent image load bearing component to recording medium;

Developing apparatus, described toner cartridge is connected with it movably, and is combined with described developing parts; And

Circulation member can be worked when described toner cartridge is in the state that is connected with described developing apparatus, no matter so that described developing parts whether work, always toner circulates between the two at described developing apparatus and described toner cartridge.

2. image forming apparatus as claimed in claim 1, it is characterized in that, further comprise control of working unit, described toner cartridge with make described circulation member work predetermined amount of time after described developing apparatus is connected, allow described developing parts to be in halted state simultaneously.

3. image forming apparatus as claimed in claim 2 is characterized in that, described toner is non magnetic one-component toner.

4. image forming apparatus as claimed in claim 3 is characterized in that, described toner is the styrene-propene polymerized toner.

5. image forming apparatus as claimed in claim 2 is characterized in that, the work the when work of described circulation member when described developing parts is in halted state is more in running order than described developing parts is rapider.

6. image forming apparatus as claimed in claim 2 is characterized in that described developing apparatus is provided with in removable mode.

7. image forming apparatus as claimed in claim 2 is characterized in that described image carrier is provided with in removable mode.

8. image forming apparatus as claimed in claim 2 is characterized in that,

Described developing parts is a developer roll, the feed rolls that described developing apparatus is combined with described developer roll and gives described developer roll with color powder feeding,

Described control of working unit makes the described predetermined amount of time of described circulation member work, allows described developer roll and described feed rolls to be in halted state simultaneously.

9. image forming apparatus as claimed in claim 2 is characterized in that,

Described developing parts is a developer roll, the feed rolls that described developing apparatus is combined with described developer roll and gives described developer roll with color powder feeding, and described feed rolls is positioned at and the not contacted position of described developer roll,

Described control of working unit makes described circulation member and the described predetermined amount of time of described feed rolls work, allows described developer roll to be in halted state simultaneously.

10. image forming apparatus as claimed in claim 2 is characterized in that, described circulation member comprises:

Supply part is arranged in the described toner cartridge, and is configured to toner is supplied to described developing apparatus from described toner cartridge;

And

Returning part is arranged in the described developing apparatus, and is configured to toner is back to the described toner cartridge from described developing apparatus.

11. image forming apparatus as claimed in claim 10 is characterized in that, described toner cartridge comprises: the driving force input block that receives driving force from the main body of image forming apparatus; And the driving force output unit that the driving force that inputs to the driving force input block can be exported to described Returning part.

12. image forming apparatus as claimed in claim 11 is characterized in that, described driving force input block and described driving force output unit and described supply part collaborative work.

13. image forming apparatus as claimed in claim 11 is characterized in that, described driving force input block and described driving force output unit are arranged on the surfaces opposite to each other of described toner cartridge.

14. image forming apparatus as claimed in claim 10 is characterized in that, described Returning part comprises:

The toner round-robin supply spiral conveyer that described toner cartridge is supplied; And

Make such round-robin toner be back to the spiral conveyer that returns in the described toner cartridge.

15. the removable cartridge that uses in the image forming apparatus is characterized in that, comprising:

Receiving portion is admitted the described toner cartridge of depositing toner with removably;

Developing parts makes from the toner of described toner cartridge through electrification by friction, toner being provided to the surface of image carrier, thereby makes the latent electrostatic image developing that forms on the described image carrier; And

Returning part makes toner be back to the described toner cartridge from described box, no matter whether the described developing parts of described Returning part works can work.

16. box as claimed in claim 15 is characterized in that, described toner is non magnetic one-component toner.

17. box as claimed in claim 16 is characterized in that, described toner is the styrene-propene polymerized toner.

18. box as claimed in claim 15 is characterized in that, described developing parts is a developer roll,

Further comprise the feed rolls of color powder feeding being given described developer roll, and

Described Returning part can work when described developer roll and described feed rolls are in halted state.

19. box as claimed in claim 15 is characterized in that, described developing parts is a developer roll,

Further comprise the feed rolls of color powder feeding being given described developer roll, described feed rolls is in and the not contacted position of described developer roll, and

Described Returning part and described feed rolls can be worked when described developer roll is in halted state.

20. box as claimed in claim 15 is characterized in that, described Returning part comprises:

The toner round-robin supply spiral conveyer that described toner cartridge is supplied; And

Make such round-robin toner be back to the spiral conveyer that returns in the described toner cartridge.

21. removable toner cartridge, be configured to be connected with developing apparatus, described developing apparatus comprises developing parts at least, described developing parts makes toner through electrification by friction, toner is provided to the surface of image carrier, thereby making the latent electrostatic image developing that forms on the described image carrier surface is toner image, it is characterized in that, described toner cartridge comprises:

Supply part no matter whether described developing parts is worked and can be worked when being connected with described developing apparatus, and is configured to supply stored toner in the described toner cartridge to described developing apparatus.

22. an image forming apparatus is characterized in that, comprising:

Form the electrostatic latent image load bearing component of electrostatic latent image on the surface that is had;

Deposit the toner cartridge of toner;

Toner is fed on the surface of described electrostatic latent image load bearing component from described toner cartridge, thereby latent electrostatic image developing is the developing parts of toner image;

With the transfer member of toner image on from the surface transfer of described electrostatic latent image load bearing component to recording medium;

Developing apparatus, described toner cartridge is connected with it movably, and is combined with described developing parts;

Toner is supplied to the supply part of described developing apparatus from described toner cartridge; And

Toner is recycled to Returning part the described toner cartridge from described developing apparatus, and described Returning part can be independent of the work of supply part and carry out work.

23. image forming apparatus as claimed in claim 22 is characterized in that, described Returning part circulates toner in described developing apparatus, thereby toner is back in the described toner cartridge.

24. image forming apparatus as claimed in claim 22 is characterized in that, described developing apparatus is provided with in removable mode.

25. image forming apparatus as claimed in claim 22 is characterized in that, described electrostatic latent image supporting body is provided with in removable mode.

26. image forming apparatus as claimed in claim 22 is characterized in that, when described Returning part work and described supply part were in halted state, described developing parts stopped.

27. image forming apparatus as claimed in claim 22 is characterized in that, further comprises:

When decision should change the replacing time detecting unit of described toner cartridge; And

Control module when the decision of described replacing time detecting unit should be changed described toner cartridge, carries out to reclaim to control that described Returning part is worked when described supply part is in halted state.

28. image forming apparatus as claimed in claim 27 is characterized in that, comprises that further the described toner cartridge of detection is to install or the attaching/detaching detecting unit of dismounting with respect to the main body of image forming apparatus,

Described replacing time detecting unit detects whether should change this toner cartridge according to the toner amount of depositing in the described toner cartridge, and

Described attaching/detaching detecting unit detects the main body that described toner cartridge has been installed to image forming apparatus, and described supply part has been worked after the scheduled volume, and described control module is being carried out the testing result of described recovery control back with reference to described replacing time detecting unit.

29. image forming apparatus as claimed in claim 28 is characterized in that,

Further comprise the housing that is formed with opening, described toner cartridge is installed to described housing by described opening and dismantles from described housing,

Described attaching/detaching detecting unit comprises that detecting described opening is in and opens the still open state detecting unit of closed condition.

30. image forming apparatus as claimed in claim 22 is characterized in that, described toner is non magnetic one-component toner.

31. the removable cartridge that uses in the image forming apparatus is characterized in that, comprising:

Receiving portion is deposited the toner cartridge of toner with the removably admittance, and is provided with the supply part of color powder feeding being given developing parts;

Described developing parts is supplied to the surface of electrostatic latent image supporting body with toner from described toner cartridge, thereby makes the latent electrostatic image developing that forms on the described image carrier; And

Toner is back to Returning part in the described toner cartridge, and described Returning part can be independent of the supply work of described supply part and carry out work.

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