Image forming apparatus

Abstract

To provide a toner cartridge that can prevent an image defect, and an image forming apparatus including the same.SOLUTION: A toner cartridge is removably attached to a developing unit having a developing roller. The toner cartridge has a frame body that extends in a longitudinal direction, and that has a storage chamber that stores toner, a first discharge port that is provided in the frame body to communicate with the storage chamber and allows passage of the toner discharged from the storage chamber to the developing unit, and a second discharge port that is provided in the frame body to communicate with the storage chamber, is arranged at a position different from the first discharge port in the longitudinal direction, and allows passage of the toner discharged from the storage chamber to the developing unit; and a partition part that partitions the storage chamber into a plurality of spaces including a first space and a second space separated from the first space. The first discharge port communicates with the first space, and the second discharge port communicates with the second space.SELECTED DRAWING: Figure 10

Description

[Technical Field]

[0001] The present invention relates to a toner cartridge that contains toner and an image forming apparatus that includes the toner cartridge. [Background technology]

[0002] In electrophotographic image forming apparatuses, a rotary development system is known in which a color image is formed by rotating a rotary equipped with multiple developing members. Patent Document 1 describes an image forming apparatus that includes a rotary equipped with multiple developing rollers and multiple toner cartridges (toner storage containers) that are each detachable from the rotary. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-096852 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the toner contained in the toner cartridge described in Patent Document 1 may become unevenly distributed inside the toner cartridge due to the transportation process before it reaches the user or the orientation of the toner cartridge during storage. This can cause variations in the amount of toner passing through the discharge opening provided in the toner cartridge, resulting in uneven toner supply to the developing unit. This can lead to image defects in areas where the toner supply to the developing unit is insufficient.

[0005] SUMMARY OF THE INVENTION An object of the present invention is to provide a toner cartridge capable of suppressing image defects and an image forming apparatus including the toner cartridge. [Means for solving the problem]

[0006] The present invention is a toner cartridge that can be attached to and detached from a development unit having a development roller, characterized in that the frame body extends in the longitudinal direction and includes: a storage chamber for storing toner; a first discharge port provided in the frame body so as to communicate with the storage chamber and through which toner passes as it is discharged from the storage chamber to the development unit; and a second discharge port provided in the frame body so as to communicate with the storage chamber and positioned at a position different from the first discharge port in the longitudinal direction and through which toner passes as it is discharged from the storage chamber to the development unit; and a partition portion that divides the storage chamber into multiple spaces including a first space and a second space separated from the first space, wherein the first discharge port communicates with the first space and the second discharge port communicates with the second space.

[0007] The present invention also provides a toner cartridge that is detachable from a development unit having a development roller, the toner cartridge comprising a frame body extending in the longitudinal direction, the frame body including a storage chamber for storing toner, and a plurality of discharge ports provided in the frame body so as to communicate with the storage chamber and arranged side by side in the longitudinal direction, through which toner passes as it is discharged from the storage chamber to the development unit, and a partition portion that divides the storage chamber into a plurality of spaces, each of which communicates with at least one of the plurality of discharge ports. [Effects of the Invention]

[0008] According to the present invention, it is possible to suppress image defects. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a schematic diagram of an image forming apparatus according to a first embodiment. [Figure 2] (a) is a cross-sectional view showing the rotary body in the developing position, (b) is a cross-sectional view showing the rotary body in the separated position, (c) is a cross-sectional view showing the rotary body in the standby position, and (d) is a cross-sectional view showing the rotary body in the replacement position. [Figure 3]1A is a cross-sectional view showing the tray and toner cartridge housed in the rotary body, and FIG. 1B is a cross-sectional view showing the tray and toner cartridge pulled out from the rotary body. [Figure 4] 1A is a schematic diagram showing a developing frame and a toner cartridge mounted on the developing frame, and FIG. 1B is a schematic diagram showing the communication direction of a communication portion. [Figure 5] (a) is a schematic diagram showing the position of the toner cartridge when toner replenishment begins, (b) to (d) are schematic diagrams showing the position of the toner cartridge during toner replenishment, and (e) is a schematic diagram showing the position of the toner cartridge when toner replenishment is complete. [Figure 6] 1A is a cross-sectional view showing a cross section perpendicular to the thickness direction of the toner cartridge, and FIG. 1B is a cross-sectional view showing a cross section perpendicular to the width direction of the toner cartridge. [Figure 7] 1A is a cross-sectional view showing the toner cartridge with the second frame removed, and FIG. 1B is a cross-sectional view showing the second frame being attached to the first frame. [Figure 8] 1A is a cross-sectional view showing a cross section perpendicular to the thickness direction of a toner cartridge according to Comparative Example 1, and FIG. 1B is a cross-sectional view showing a cross section perpendicular to the width direction of a toner cartridge according to Comparative Example 1. FIG. [Figure 9] FIG. 4 is a perspective view showing the attitude of the toner cartridge during a tapping test. [Figure 10] 1A is a cross-sectional view showing the state of the toner after the tapping test according to Example 1, and FIG. 1B is a cross-sectional view showing the state of the toner after the toner has been consumed. [Figure 11] FIG. 10(a) is a cross-sectional view showing the state of the toner after a tapping test according to Comparative Example 1, and FIG. 10(b) is a cross-sectional view showing the state of the toner after the toner has been consumed. [Figure 12] 1A is a cross-sectional view showing the internal structure of a toner cartridge according to a first modified example of the first embodiment, and FIG. 1B is a cross-sectional view showing the internal structure of a toner cartridge according to a second modified example of the first embodiment. [Figure 13] 10A is a cross-sectional view showing a toner cartridge according to a second embodiment, and FIG. 10B is a cross-sectional view showing the positional relationship between the toner cartridge and a scanner. [Figure 14]10A is a cross-sectional view showing a toner cartridge according to Comparative Example 2, and FIG. 10B is a cross-sectional view showing the positional relationship between the toner cartridge and a scanner. [Figure 15] 10A is a cross-sectional view showing the state of the toner after a tapping test according to Example 2, and FIG. 10B is a cross-sectional view showing the state of the toner after the toner has been consumed. [Figure 16] 10A is a cross-sectional view showing the state of the toner after a tapping test according to Comparative Example 2, and FIG. 10B is a cross-sectional view showing the state of the toner after the toner has been consumed. [Figure 17] 10A is a cross-sectional view showing a cross section perpendicular to the thickness direction of a toner cartridge according to a third embodiment, and FIG. 10B is a cross-sectional view showing a cross section perpendicular to the width direction of the toner cartridge. [Figure 18] 10A is a cross-sectional view showing a cross section perpendicular to the thickness direction of a toner cartridge according to Comparative Example 3, and FIG. 10B is a cross-sectional view showing a cross section perpendicular to the widthwise direction of the toner cartridge. [Figure 19] 1A is a cross-sectional view showing the toner cartridge with the second frame removed, and FIG. 1B is a cross-sectional view showing the second frame being attached to the first frame. [Figure 20] Schematic view in the Y direction showing the toner cartridge rotating about its axis of rotation. [Figure 21] (a) is a schematic diagram showing a cross section perpendicular to the Y direction and a cross section perpendicular to the H direction of the toner cartridge at position Tp3 in Figure 20, and (b) is a schematic diagram showing a cross section perpendicular to the Y direction and a cross section perpendicular to the H direction of the toner cartridge at position Tp7 in Figure 20. [Figure 22] 10A is a cross-sectional view showing the state of the toner after a tapping test according to Example 3, and FIG. 10B is a cross-sectional view showing the state of the toner after the toner has been consumed. [Figure 23] 10A is a cross-sectional view showing the state of the toner after a tapping test according to Comparative Example 3, and FIG. 10B is a cross-sectional view showing the state of the toner after the toner has been consumed. [Figure 24] 10A is a cross-sectional view showing a cross section perpendicular to the thickness direction of a toner cartridge according to a modification of the third embodiment, and FIG. 10B is a cross-sectional view showing a cross section perpendicular to the width direction of the toner cartridge. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0011] Example 1 An image forming apparatus 1 according to a first embodiment will be described. In the following description and in each drawing, the vertical direction when the image forming apparatus 1 is installed on a horizontal surface is referred to as the Z direction. The direction of a rotation axis 90C of a rotary body 90 (described later) (rotary axis direction) that intersects with the Z direction is referred to as the Y direction. The direction of the rotation axis of the photosensitive drum 2 (photosensitive drum rotation axis direction) is also parallel to the direction of the rotation axis 90C of the rotary body 90, which is referred to as the Y direction. The direction that intersects with both the Z direction and the Y direction is referred to as the X direction. The X direction and the Y direction are preferably horizontal. The X direction, Y direction, and Z direction are preferably perpendicular to each other. Furthermore, as necessary, the directions of the arrows X, Y, and Z shown in each drawing will be referred to as the +X side, +Y side, and +Z side, respectively, and the opposite sides will be referred to as the -X side, -Y side, and -Z side, respectively.

[0012] (Overall configuration of image forming apparatus) First, we will explain the overall configuration of the image forming apparatus 1. The image forming apparatus 1 is a laser beam printer that forms an image on a sheet S by electrophotography. More specifically, the image forming apparatus 1 is a color laser beam printer equipped with four development units 50y, 50m, 50c, and 50k. As the sheet S, which is the recording material (recording medium), a variety of sheet materials of different sizes and materials can be used, including paper such as plain paper and cardboard, surface-treated sheet materials such as plastic film, cloth, and coated paper, and sheet materials of special shapes such as envelopes and index paper.

[0013] The schematic configuration and image forming operation of the image forming apparatus 1 will be described with reference to Fig. 1. Fig. 1 is a schematic diagram showing the cross-sectional configuration of the image forming apparatus 1.

[0014] 1, the image forming apparatus 1 includes an image forming apparatus main body (hereinafter referred to as the apparatus main body) 1A and toner cartridges 70y, 70m, 70c, and 70k that are detachably attached to the apparatus main body 1A. The apparatus main body 1A in this embodiment is the portion of the image forming apparatus 1 excluding the toner cartridges 70y, 70m, 70c, and 70k.

[0015] An apparatus main body 1A of the image forming apparatus 1 has a drum-shaped (cylindrical) electrophotographic photosensitive member (hereinafter referred to as photosensitive drum) 2 as an image carrier that carries an electrostatic latent image. Around the photosensitive drum 2, a charging roller 3, a scanner 4 as an exposure device, and a cleaning unit 6 are arranged.

[0016] The charging roller 3 is an example of a charging means or charging unit for uniformly charging the photosensitive drum 2. The scanner 4 is an example of an exposure means or exposure unit that irradiates the photosensitive drum 2 with laser light according to image information to expose it. By irradiating the charged photosensitive drum 2 with laser light, an electrostatic latent image is formed on the surface of the photosensitive drum 2. The cleaning unit 6 is an example of a cleaning means or cleaning section that removes toner remaining on the surface of the photosensitive drum 2.

[0017] Furthermore, the apparatus main body 1A has a sheet storage section 300, a pickup roller 310, a feed roller 311, a separation roller 312, a pair of conveying rollers 320, a secondary transfer roller 12, a fixing device 40, and an intermediate transfer unit 10. The pickup roller 310 is an example of a feeding means or a feeding unit that feeds the sheet S. The feed roller 311 and the separation roller 312 are examples of a separation conveying unit that separates and conveys the sheets S one by one by frictional force. The secondary transfer roller 12 is an example of a transfer means or a transfer unit that transfers an image from the intermediate transfer belt 10a to the sheet S.

[0018] The intermediate transfer unit 10 has an intermediate transfer belt 10a, a belt drive roller 10b, a tension roller 10c, a cleaning device 13, and a primary transfer roller 11. The intermediate transfer belt 10a is an example of an intermediate transfer body that carries an image transferred (primary transfer) from the photosensitive drum 2 and transports it to be transferred (secondary transfer) to a sheet S. The intermediate transfer belt 10a is stretched over the belt drive roller 10b and the tension roller 10c. The belt drive roller 10b is a drive member that is rotationally driven by a drive source to transport the intermediate transfer belt 10a.

[0019] The apparatus main body 1A also has a rotary main body (rotary, rotating body, developing device) 90 having developing units 50y, 50m, 50c, and 50k. As will be described later, in this embodiment, trays (support members) 80y, 80m, 80c, and 80k are attached to the rotary main body 90. Toner cartridges 70y, 70m, 70c, and 70k are removably attached to the trays 80y, 80m, 80c, and 80k.

[0020] In the following description, multiple components with similar functions may be distinguished by numbers. For example, one of the toner cartridges 70y, 70m, 70c, and 70k may be referred to as the first toner cartridge, one of the remaining three as the second toner cartridge, one of the remaining two as the third toner cartridge, and the last one as the fourth toner cartridge. Similarly, one of the trays 80y, 80m, 80c, and 80k may be referred to as the first tray, one of the remaining three as the second tray, one of the remaining two as the third tray, and the last one as the fourth tray. In other words, one of the trays 80y to 80k is an example of a first support member, another of the trays 80y to 80k is an example of a second support member, yet another of the trays 80y to 80k is an example of a third support member, and the last of the trays 80y to 80k is an example of a fourth support member. These numbering schemes are used merely for convenience and, in principle, can be interchanged as appropriate.

[0021] The developing units (first to fourth developing units) 50y, 50m, 50c, and 50k are examples of developing means or developing sections that develop (visualize) the electrostatic latent image formed on the photosensitive drum 2 into a toner image using toner of the corresponding color. The developing units 50y, 50m, 50c, and 50k develop the electrostatic latent image formed on the photosensitive drum 2 using yellow toner, magenta toner, cyan toner, or black toner, respectively. The developing units 50y, 50m, 50c, and 50k may be arranged in an order different from that shown in FIG. 1.

[0022] The developing unit 50y has a developing roller 51y, a supply roller 52y, and a developing blade. The developing roller 51y is a developer carrier that carries toner as a developer and rotates to supply the toner to the photosensitive drum 2. The supply roller 52y is disposed in contact with the developing roller 51y and is a supply member that supplies toner to the developing roller 51y. The developing blade is a regulating member that regulates the thickness of the toner layer carried by the developing roller 51y. The other developing units 50m, 50c, and 50k also have similar developing rollers 51m, 51c, and 51k, supply rollers 52m, 52c, and 52k, and developing blades.

[0023] (Rotary configuration) The configuration of the rotary body 90 will be described using FIGS. 1 to 4(b). As shown in FIG. 1, the rotary body 90 is fitted with toner cartridges 70y, 70m, 70c, and 70k corresponding to the development units 50y, 50m, 50c, and 50k. The toner cartridges 70y, 70m, 70c, and 70k contain yellow toner, magenta toner, cyan toner, and black toner, respectively, to supply the development units 50y, 50m, 50c, and 50k. One of the four toner colors can be referred to as the first toner, one of the remaining three toner colors as the second toner, one of the remaining two toner colors as the third toner, and the last toner as the fourth toner. For example, black toner can be referred to as the first toner, and magenta toner as the second toner. These numbering schemes are used merely for convenience and can, in principle, be interchanged as appropriate.

[0024] The rotary main body 90 has a rotary frame 90f that supports the developing units 50y, 50m, 50c, and 50k. The developing units 50y, 50m, 50c, and 50k are supported by the rotary frame 90f, which is a rotatable support body.

[0025] Trays 80y, 80m, 80c, and 80k are attached to the rotary body 90. The combination of the rotary body 90 and the trays 80y, 80m, 80c, and 80k can be called the rotary unit 90U. In other words, the rotary unit 90U has the rotary body 90 and the trays 80y, 80m, 80c, and 80k.

[0026] The toner cartridges 70y-70k are detachably held in the trays 80y-80k. As will be described later, the trays 80y-80k are supported so as to be slidable to the outside of the rotary main body 90. The combination of the rotary unit 90U and the toner cartridges 70y, 70m, 70c, and 70k can be referred to as the rotary assembly 90A. In other words, the rotary assembly 90A has the rotary unit 90U and the toner cartridges 70y, 70m, 70c, and 70k.

[0027] The rotary body 90 is rotatable around a rotation axis (rotation center) 90C. The rotation axis 90C coincides with the rotation axes of the rotary frame 90f, the rotary unit 90U, and the rotary assembly 90A. The rotation axis 90C is also substantially parallel to the rotation axis (rotation center) of the photosensitive drum 2.

[0028] Fig. 2(a) is a cross-sectional view showing the rotary body 90 in the developing position, Fig. 2(b) is a cross-sectional view showing the rotary body 90 in the separated position, Fig. 2(c) is a cross-sectional view showing the rotary body 90 in the standby position, and Fig. 2(d) is a cross-sectional view showing the rotary body 90 in the replacement position.

[0029] 1 and 2(a), the rotary body 90 rotates around a rotation axis 90C, thereby being able to assume a developing posture in which any one of the developing rollers 51y, 51m, 51c, and 51k abuts against the photosensitive drum 2. Disk gears are formed on both ends of the rotary body 90 in the Y direction, and the disk gears are engaged with rotary drive gears (not shown). When the rotary drive gears are driven by a motor (not shown), the disk gears and the rotary body 90 rotate around the rotation axis 90C.

[0030] The position in which the developing roller 51y contacts the photosensitive drum 2 is called the yellow developing position. The position in which the developing roller 51m contacts the photosensitive drum 2 is called the magenta developing position. The position in which the developing roller 51c contacts the photosensitive drum 2 is called the cyan developing position. The position in which the developing roller 51k contacts the photosensitive drum 2 is called the black developing position. In other words, the rotary body 90 can rotate around the rotation axis 90C so that the positions of the developing rollers 51y, 51m, 51c, and 51k relative to the photosensitive drum 2 change. The black developing position is an example of a first developing position in which the first developing roller (developing roller 51k) contacts the photosensitive drum 2. The other developing positions are examples of a second developing position in which the second developing roller (developing rollers 51y to 51c) contact the photosensitive drum 2. The yellow / magenta / cyan / black developing positions can also be called first to fourth developing positions. These numbering schemes are used merely for convenience in explanation, and in principle can be interchanged as appropriate.

[0031] Here, the subscripts y, m, c, and k attached to the developing units 50y, 50m, 50c, and 50k, the toner cartridges 70y, 70m, 70c, and 70k, and the trays 80y, 80m, 80c, and 80k indicate the toner color. The developing units 50y, 50m, 50c, and 50k share the same basic configuration and function. The toner cartridges 70y, 70m, 70c, and 70k also share the same basic configuration and function. The trays 80y, 80m, 80c, and 80k also share the same basic configuration and function. Therefore, when it is not necessary to distinguish between them, the subscripts y, m, c, and k are omitted and the unit is described as any one of the four units, cartridges, and trays. Furthermore, when it is necessary to distinguish between the four units, cartridges, and trays, the subscripts y, m, c, and k are added and the unit is described as one of the four units, cartridges, and trays corresponding to the subscript.

[0032] The rotary body 90 is supported so as to be able to swing about a swing shaft 91. The rotary body 90 is urged by a biasing member (not shown) in the counterclockwise direction in FIGS. 1 to 2(d) about the swing shaft 91. This direction can be said to be the direction in which each of the developing rollers 51y to 51k approaches the photosensitive drum 2. As a result, when the rotary body 90 is in the developing position, each of the developing rollers 51y to 51k abuts against the photosensitive drum 2. In FIG. 2(a), the rotary body 90 is in the black developing position in which the developing roller 51k abuts against the photosensitive drum 2.

[0033] As shown in FIG. 1, the apparatus main body 1A has a frame 16 that houses the rotary body 90. The frame 16 is the main body frame of the image forming apparatus 1 in this embodiment. The frame 16 is a housing (skeleton) of the apparatus main body 1A that is composed of a frame and exterior members, and in this embodiment, is approximately rectangular parallelepiped-shaped. The frame 16 rotatably supports a cam 96, which is configured to be able to abut against the rotary body 90. When the cam 96 rotates, the rotary body 90 is pressed by the cam 96 and rotates clockwise around the swing shaft 91, as indicated by the dashed arrow in FIG. 2(b). This direction can be said to be the direction in which each of the developing rollers 51y to 51k moves away from the photosensitive drum 2. This direction can also be said to be the direction in which the rotary body 90 approaches the opening 16a of the frame 16 and the door 14. As a result, the developing roller 51k provided in the rotary body 90 moves away from the photosensitive drum 2. The posture of the rotary body 90 in this state where the developing roller 51 faces the photosensitive drum 2 but is spaced apart from the photosensitive drum 2 is called the spaced posture.

[0034] Furthermore, when the image forming apparatus 1 is waiting for image formation to be performed, the rotary body 90 assumes a standby position in which the photosensitive drum 2 and the developing roller 51 are spaced apart, with the photosensitive drum 2 positioned between the developing rollers 51c and 51k, as shown in FIG. 2(c). When the user replaces the toner cartridge 70, the rotary body 90 assumes the replacement position shown in FIG. 2(d). When the rotary body 90 assumes the replacement position, the photosensitive drum 2 and the developing roller 51 are spaced apart, and one of the toner cartridges 70 is positioned approximately horizontally. In FIG. 2(d), the black toner cartridge 70k is positioned horizontally.

[0035] As described above, the toner cartridges 70y to 70k are detachable from the rotary body 90. When the toner in the toner cartridges 70y to 70k runs out, the user can replenish toner in the image forming apparatus 1 by replacing the toner cartridges 70y to 70k with new ones.

[0036] Next, with reference to Figures 1 and 3(a, b), the attachment and detachment of the toner cartridge 70k to and from the rotary body 90 will be described. Figure 3(a) is a cross-sectional view showing the tray 80k and toner cartridge 70k housed in the rotary body 90, and Figure 3(b) is a cross-sectional view showing the tray 80k and toner cartridge 70k pulled out of the rotary body 90.

[0037] As shown in FIGS. 1 and 3(a, b), the frame 16 has an opening 16a. More specifically, the frame 16 has a side surface 16b that extends in a direction intersecting the horizontal direction. The side surface 16b constitutes at least a part of the exterior surface on the +X side of the device main body 1A. The opening 16a is located on this side surface 16b. The side surface 16b is located downstream of the discharge port in the discharge direction in which sheets S on which images are formed are discharged from the discharge port of the device main body 1A. A user can access the sheet storage unit 300 from the side surface 16b of the image forming apparatus 1 to refill sheets S or retrieve sheets S discharged from the discharge port. Therefore, the side surface 16b can be said to be the front surface (front face) of the device main body 1A.

[0038] Toner cartridges 70y, 70m, 70c, and 70k are detachably attached to the rotary body 90 through the opening 16a. In other words, toner cartridge 70k is an example of a first toner cartridge that contains toner to be supplied to the first developing roller (developing roller 51k) and is detachably attached to the rotary (rotary body 90) through the opening 16a of the frame 16 of the apparatus main body 1A. Toner cartridge 70m is an example of a second toner cartridge that contains toner to be supplied to the second developing roller (developing roller 51m) and is detachably attached to the rotary (rotary body 90) through the opening 16a of the frame 16 of the apparatus main body 1A.

[0039] In this embodiment, the toner cartridges 70y, 70m, 70c, and 70k are supported by the trays 80y to 80k and are attached to and detached from the rotary body 90 through the opening 16a. In other words, the user can attach and detach the toner cartridges 70y to 70k to and from the rotary body 90 via the trays 80y to 80k.

[0040] In this embodiment, the side surface 16b is a surface that is approximately parallel to the rotation axis 90C of the rotary body 90. Therefore, when the toner cartridge 70 is replaced, the toner cartridge 70 passes through the opening 16a in a direction intersecting (preferably perpendicular to) the rotation axis 90C.

[0041] The image forming apparatus 1 has a door 14 that covers the opening 16a of the frame 16. The door 14 is an openable / closable member that can be moved between a closed position (position shown in FIG. 3(a)) that covers the opening 16a and an open position (position shown in FIG. 3(b)) that exposes the opening 16a.

[0042] As described above, in this embodiment, the toner cartridge 70 is configured to be detachable from the rotary body 90 via the tray 80. Therefore, the toner cartridge 70 can be detachable from the rotary body 90 in a stable manner.

[0043] More specifically, the user can replace the toner cartridge 70 by inserting or removing the toner cartridge 70 into or from the tray 80, which is configured to be movable relative to the rotary body 90 (i.e., relative to the device main body 1A). In a configuration in which the user replaces the toner cartridge by directly inserting or removing the toner cartridge into or from the device main body, the user is required to insert the toner cartridge to a predetermined installation position within the device main body. In this embodiment, the tray 80 is movable so that the toner cartridge 70 moves to the installation position while supporting the toner cartridge 70. Therefore, the user can replace the toner cartridge 70 by simply placing the toner cartridge 70 on the tray 80, improving operability.

[0044] The toner cartridge 70 has an elongated shape with its longitudinal direction being the Y direction parallel to the rotation axis 90C of the rotary body 90. In other words, the longitudinal dimension of the toner cartridge 70 is greater than the height and width of a cross section perpendicular to the longitudinal direction. When handling such an elongated toner cartridge 70, by locating the opening 16a on the side surface 16b of the frame 16 that is approximately parallel to the longitudinal direction (Y direction) of the toner cartridge 70, the toner cartridge 70 can pass through the opening 16a with a short movement distance. For example, this makes it easier to replace the toner cartridge 70 than when inserting or removing the toner cartridge 70 through an opening provided on the side surface of either side (+Y side or −Y side) of the frame 16 in the longitudinal direction of the toner cartridge 70.

[0045] The rotary body 90 can rotate about a rotation axis 90C and assume replacement positions that allow removal of any of the toner cartridges 70y to 70k from the rotary body 90. The position that allows removal of the toner cartridge 70y is called the yellow replacement position. The position that allows removal of the toner cartridge 70m is called the magenta replacement position. The position that allows removal of the toner cartridge 70c is called the cyan replacement position.

[0046] The position in which removal of the toner cartridge 70k is permitted is called the black replacement position. The black replacement position is an example of a first replacement position in which removal of the first toner cartridge from the rotary body 90 is permitted. The yellow / magenta / cyan replacement position is an example of a second replacement position in which removal of the second toner cartridge from the rotary body 90 is permitted. The yellow / magenta / cyan / black replacement positions can also be called the first to fourth replacement positions. These numberings are used merely for convenience of explanation and can, in principle, be interchanged as appropriate.

[0047] The rotary body 90 rotates about a rotation axis 90C in a clockwise direction in Figure 1, and can sequentially assume yellow / magenta / cyan / black replacement positions. In Figures 3(a) and 3(b), the rotary body 90 is in the black replacement position.

[0048] As shown in Figures 3(a) and 3(b), four trays 80y to 80k are attached to the rotary main body 90. The trays 80y to 80k hold the toner cartridges 70y to 70k, respectively. In Figure 3(a), the trays 80y to 80k are housed inside the rotary main body 90, which can be said to be the state in which the toner cartridges 70y to 70k are attached to the development units 50y, 50m, 50c, and 50k.

[0049] As described above, the toner cartridge 70 is movable between an attached position and a retracted position retracted from the attached position relative to the developing frame 53 (rotary body 90) of the developing unit 50. That is, the first toner cartridge (toner cartridge 70k) is movable between a first attached position and a first retracted position relative to the first accommodating frame (developing frame 53k). The second toner cartridge (toner cartridge 70m) is movable between a second attached position and a second retracted position relative to the second accommodating frame (developing frame 53m).

[0050] For example, when removing the black toner cartridge 70k from the rotary body 90, the rotary body 90 assumes the black replacement position, as shown in FIG. 3(a). At this time, the rotary body 90 is stopped in a position where the toner cartridge 70k faces the opening 16a and the door 14. The door 14 is then moved from the closed position to the open position, and the opening 16a provided in the side surface 16b of the frame 16 is opened (exposed). Next, the tray 80k slides through the opening 16a from the storage position in the rotary body 90 to the extracted position outside the frame 16. With the tray 80k in the extracted position, the toner cartridge 70k is in the retracted position, allowing the user to remove the toner cartridge 70k from the tray 80k. When the toner cartridge 70k is installed in the rotary body 90, the above-described procedure is reversed.

[0051] In this embodiment, the toner cartridge 70k containing black toner is larger in size and can contain more toner than the toner cartridges 70y to 70c containing yellow, magenta, and cyan toners. In other words, the first toner cartridge can contain a first amount of toner, and the second toner cartridge can contain a second amount of toner, with the first amount being greater than the second amount.

[0052] Specifically, the length of the black toner cartridge 70k in a first radial direction relative to the rotation axis 90C of the rotary body 90 is longer than the length of the magenta toner cartridge 70m in a second radial direction. Here, the first radial direction is the rotation radius direction of the rotary body 90 (the radial direction of an imaginary circle centered on the rotation axis 90C), and is the direction in which the toner cartridge 70k extends relative to the rotation axis 90C when viewed in the direction of the rotation axis 90C. The second radial direction is the rotation radius direction of the rotary body 90, and is the direction in which the toner cartridge 70m extends relative to the rotation axis 90C when viewed in the direction of the rotation axis 90C. Similarly, the length of the black toner cartridge 70k in the first radial direction is longer than the lengths of the toner cartridges 70y and 70c in the radial directions corresponding to the other toner cartridges 70y and 70c.

[0053] Therefore, the tray 80k holding the black toner cartridge 70k is larger than the trays 80y-80c holding the other toner cartridges 70y, 70m, and 70c. That is, four toner cartridges 70y-70k and trays 80y-80k of different sizes are arranged inside the rotary body 90. In other words, the rotary body 90 is removably fitted with the toner cartridge 70k as an example of a first toner cartridge and the toner cartridge 70y as an example of a second toner cartridge that is smaller in size than the first toner cartridge. Accordingly, the rotary body 90 is provided with the tray 80k as an example of a first support member that supports the first toner cartridge and the tray 80y as an example of a second support member that is smaller in size than the first support member. The rotary body 90 is also removably fitted with the toner cartridges 70m and 70c as examples of third and fourth toner cartridges that are smaller in size than the first toner cartridge. Accordingly, the rotary body 90 is provided with trays 80m and 80c as examples of third and fourth support members that are smaller in size than the first support member.

[0054] 4(a) and 4(b) are schematic diagrams showing the developing device frame 53 and the toner cartridge 70 attached to the developing device frame 53. As shown in FIG. 4(a), the toner cartridge 70 has a toner frame 71 as a frame. The toner frame 71 has a toner storage section 71a as a storage chamber that stores toner, and a discharge opening 71b that communicates with the toner storage section 71a. A plurality of discharge openings 71b are provided in the Y direction, i.e., the longitudinal direction of the toner cartridge 70.

[0055] The developing unit 50 has a developing frame (storage frame) 53. The developing frame 53 has a developing-side storage portion 53a (storage portion) and a receiving opening 53b that communicates with the developing-side storage portion (toner supply chamber) 53a. A plurality of receiving openings 53b are provided in the Y direction, i.e., the longitudinal direction of the toner cartridge 70, and the number of receiving openings 53b is the same as the number of discharge openings 71b. That is, the rotary body 90 has a developing frame 53y, a developing frame 53m, a developing frame 53c, and a developing frame 53k (see FIG. 3(a)). That is, the rotary body 90 has a first developing chamber, a second developing chamber, a third developing chamber, and a fourth developing chamber. As mentioned above, the developing unit 50 has the developing roller 51, the supply roller 52, etc., but these components are omitted in FIGS. 4(a) and 4(b).

[0056] The developing roller 51k included in the developing unit 50k is an example of a first developing roller. The developing roller 51m included in the developing unit 50m is an example of a second developing roller. The developing frame 53k (FIG. 3(a)) of the developing unit 50k having the developing-side accommodating portion 53a is an example of a first accommodating frame having a first accommodating portion. The developing frame 53m (FIG. 3(a)) of the developing unit 50m having the developing-side accommodating portion 53a is an example of a second accommodating frame having a second accommodating portion. The rotary body 90 is an example of a rotatable rotary having a first developing roller, a second developing roller, a first accommodating frame having a first accommodating portion, and a second accommodating frame having a second accommodating portion. In this embodiment, the rotary body 90 has first to fourth developing rollers and first to fourth accommodating frames.

[0057] As shown in FIG. 4A, when the toner cartridge 70 is in the mounted position relative to the developing frame 53, the discharge opening 71b faces the receiving opening 53b. That is, the toner storage compartment 71a of the toner cartridge 70 and the developer-side storage compartment 53a of the developing unit 50 communicate with each other via a communication section 60 defined by the discharge opening 71b and the receiving opening 53b. As will be described in detail later, when toner is supplied from the toner cartridge 70 to the developing unit 50, the direction of the communication section 60 is oriented vertically downward (in the -Z direction) relative to the horizontal. The direction of the communication section 60 is from the discharge opening 71b toward the receiving opening 53b, which will be illustrated below as the communication direction E1. When toner is supplied from the toner cartridge 70 to the developing unit 50, at least a portion of the receiving opening 53b is positioned below at least a portion of the discharge opening 71b.

[0058] The toner contained in the toner container 71a is discharged from the discharge opening 71b, and the toner discharged from the discharge opening 71b is received in the developer container 53a through the receiving opening 53b. That is, the first developer is supplied to the first developing chamber of the rotary body 90, the second developer is supplied to the second developing chamber, the third developer is supplied to the third developing chamber, and the fourth developer is supplied to the fourth developing chamber.

[0059] The toner contained in the developer-side container 53a is supplied to the developing roller 51 by the supply roller 52. The toner contained in the toner container 71a is supplied to the developing roller 51 through this route.

[0060] The toner cartridge 70 preferably has a sealing member (first sealing member) (not shown) that covers the discharge opening 71b. The developing unit 50 preferably has a sealing member 55 (second sealing member) that covers the receiving opening 53b, as shown in FIGS. 4(a) and 4(b). The sealing member 55 is rotatable about a rotation axis 55a at one end and rotates due to gravity acting on the sealing member 55 to open and close the receiving opening 53b. For example, as shown in FIG. 4(a), when the communicating portion 60 is oriented downward in the vertical direction (-Z direction) relative to the horizontal, the sealing member 55 opens the receiving opening 53b and does not prevent the movement of toner passing through the communicating portion 60. For example, as shown in FIG. 4(b), when the communicating portion 60 is oriented upward in the vertical direction (+Z direction) relative to the horizontal, the sealing member 55 closes the receiving opening 53b and prevents toner from passing through the communicating portion 60. That is, the sealing member 55 functions as a check valve that allows the passage of toner in only one direction.

[0061] Furthermore, when the toner cartridge 70 is not attached to the developing unit 50, it is desirable that the discharge opening 71b and the receiving opening 53b are each covered with a sealing member so as to prevent toner from leaking out from the discharge opening 71b and the receiving opening 53b.

[0062] (Image formation operation) Next, the image forming operation in this embodiment will be described. When the image forming apparatus 1 receives image information from an external device (not shown), such as a host computer, it sends a print signal and starts the image forming operation. First, with the rotary body 90 in a standby position, the photosensitive drum 2 rotates in the direction of arrow R1 (counterclockwise) in FIG. 1 in synchronization with the rotation of the intermediate transfer belt 10a. Then, the surface of the photosensitive drum 2 is uniformly charged by the charging roller 3.

[0063] When a color image is formed on the sheet S, the rotary body 90 rotates in the direction of arrow R2 (clockwise) in FIG. 1 while supporting the developing units 50y, 50m, 50c, and 50k. First, the scanner 4 irradiates the photosensitive drum 2 with laser light based on image data corresponding to a yellow image, forming an electrostatic latent image corresponding to the yellow image on the surface of the photosensitive drum 2. In parallel with the formation of this electrostatic latent image, the rotary body 90 is rotated by a DC brush motor (not shown).

[0064] That is, the rotary body 90 rotates from the standby position shown in Figure 2(c) around the rotation axis 90C in the direction of arrow R2. Then, as the cam 96 rotates with the developing roller 51y facing the photosensitive drum 2, the rotary body 90 swings around the swing shaft 91 and assumes the yellow developing position. At this time, the developing roller 51y comes into contact with the photosensitive drum 2. When the rotary body 90 is in the yellow developing position, the developing roller 51y is in the developing position and develops the electrostatic latent image formed on the photosensitive drum 2 with yellow toner.

[0065] In this embodiment, each of the developing rollers 51y, 51m, 51c, and 51k is an elastic roller with a metal shaft covered with rubber. At the developing position, each of the developing rollers 51y, 51m, 51c, and 51k develops an electrostatic latent image while in contact with the photosensitive drum 2. In other words, the image forming apparatus 1 in this embodiment employs a contact development system. However, each of the developing rollers 51y, 51m, 51c, and 51k may also develop an electrostatic latent image while a gap is provided between the developing rollers 51y, 51m, 51c, and 51k and the photosensitive drum 2 at the developing position. In other words, the image forming apparatus 1 may employ a non-contact development system.

[0066] When the yellow toner image is developed, the yellow toner image on the photosensitive drum 2 is primarily transferred onto the intermediate transfer belt 10a by the primary transfer roller 11 disposed inside the intermediate transfer belt 10a.

[0067] Thereafter, the rotary body 90 is rotated to move the developing rollers 51m, 51c, and 51k to the developing positions in order, thereby forming toner images of each color. That is, after a yellow toner image is formed on the intermediate transfer belt 10a, the cam 96 rotates to separate the developing roller 51y from the photosensitive drum 2, and the rotary body 90 rotates about the rotation axis 90C. Thereafter, the cam 96 rotates again to bring the developing roller 51m into contact with the photosensitive drum 2, and the rotary body 90 assumes a magenta developing position. Then, the electrostatic latent image formed on the photosensitive drum 2 is developed with magenta toner.

[0068] In this embodiment, the rotary body 90 does not rotate during the contact / separation operation in which the developing roller 51 contacts or separates from the photosensitive drum 2, but this is not limiting. For example, in order to shorten the image formation time, the contact / separation operation between the developing roller 51 and the photosensitive drum 2 may be performed while the rotary body 90 is rotating. In this case, however, it is necessary to take more time than before to increase and decrease the rotary rotation speed so that vibrations caused when the developing roller 51 contacts or separates from the photosensitive drum 2 do not affect image formation operations such as charging and exposure.

[0069] After a magenta toner image is formed on the intermediate transfer belt 10a, the rotary body 90 assumes a cyan developing position, and a cyan toner image is formed on the intermediate transfer belt 10a. After a cyan toner image is formed on the intermediate transfer belt 10a, the rotary body 90 assumes a black developing position, and a black toner image is formed on the intermediate transfer belt 10a.

[0070] When a color image is to be formed continuously after a black toner image has been formed on the intermediate transfer belt 10a, the rotary body 90 rotates around the rotation axis 90C in the direction of arrow R2 (clockwise) shown in FIG. 1 and returns to the yellow developing position. When a color image is not to be formed continuously, the rotary body 90 returns to the standby position. Note that the color of the image formed first on the intermediate transfer belt 10a is arbitrary; for example, a black toner image may be formed first.

[0071] Then, primary transfer is repeated so that the four color toner images are superimposed on the intermediate transfer belt 10a, thereby forming a color image on the intermediate transfer belt 10a. Note that until the color image is formed on the intermediate transfer belt 10a, the secondary transfer roller 12 and the cleaning device 13 are not in contact with the intermediate transfer belt 10a. After the color image is formed on the intermediate transfer belt 10a, the secondary transfer roller 12 and the cleaning device 13 come into contact with the intermediate transfer belt 10a in preparation for secondary transfer.

[0072] Meanwhile, sheets S are fed by a pickup roller 310 from a sheet storage unit 300 provided at the bottom of the apparatus main body 1A. The sheets S are separated into individual sheets by a feed roller 311 and a separation roller 312 and then fed to a pair of conveying rollers 320. The pair of conveying rollers 320 sends the fed sheets S to a transfer unit (secondary transfer unit), which is a nip between the intermediate transfer belt 10a and the secondary transfer roller 12. The color image on the intermediate transfer belt 10a is transferred (secondary transfer) onto the surface of the conveyed sheet S.

[0073] The sheet S onto which the color image has been transferred is sent to the fixing device 40. In the fixing device 40, the sheet S is heated and pressurized, and the image is fixed onto the sheet S. After passing through the fixing device 40, the sheet S is discharged outside the image forming apparatus 1 as a finished product.

[0074] On the other hand, when a black monochrome image is formed on the sheet S, the rotary body 90 takes the black developing position. In this state, an electrostatic latent image is formed on the surface of the photosensitive drum 2 by charging and exposing the photosensitive drum 2, and then the electrostatic latent image is developed with black toner by the developing roller 51k located at the developing position. When black monochrome images are to be formed consecutively, the rotary body 90 continues development while remaining in the black developing position. When black monochrome images are not to be formed consecutively, the rotary body 90 returns to the standby position. The black toner image is primarily transferred to the intermediate transfer belt 10a, and then secondarily transferred to the sheet S. The subsequent processes are the same as those for color images.

[0075] (Toner supply operation) Next, the toner supply operation for supplying toner from the toner cartridge 70 to the developing unit 50 will be described with reference to Figures 5(a) to 5(e). Figure 5(a) is a schematic diagram showing the orientation of the toner cartridge 70 at the start of toner supply. Figures 5(b) to 5(d) are schematic diagrams showing the orientation of the toner cartridge 70 during toner supply. Figure 5(e) is a schematic diagram showing the orientation of the toner cartridge 70 after toner supply has been completed.

[0076] The posture of the rotary body 90 when toner is supplied from the toner cartridge 70 to the developing unit 50 after the rotary body 90 has rotated once around the rotation axis 90C is called the supply posture. Note that in this embodiment, the toner cartridge 70 is provided with multiple discharge openings 71b, but for simplicity, the following description will focus on toner supply from one discharge opening 71b.

[0077] As described above, the toner contained in the toner container 71a of the toner cartridge 70 is discharged through the discharge opening 71b and then received in the developer container 53a through the receiving opening 53b. This toner supply operation is performed by the movement of the toner due to gravity. Therefore, when the communication direction E1 between the toner cartridge 70 to be supplied and the communication portion 60 of the developing frame 53 is directed vertically downward rather than horizontally, the rotary body 90 assumes the supply posture.

[0078] For example, the supply posture of the rotary body 90 starts from a posture in which the communication direction E1 is parallel to the horizontal direction, as shown in Fig. 5(a), and is rotated even slightly in the direction of arrow R2 (clockwise).The supply posture of the rotary body 90 then passes through a posture in which the communication direction E1 is directed vertically downward rather than horizontal, as shown in Fig. 5(b) to 5(d), and reaches a posture just before the communication direction E1 is again parallel to the horizontal direction, as shown in Fig. 5(e).

[0079] On the other hand, when the communication direction E1 of the communication portion 60 is parallel to the horizontal direction or is more oriented vertically upward than the horizontal direction or more oriented vertically upward than the vertical direction, the communication portion 60 is blocked by the sealing member 55. This makes it possible to prevent toner from flowing back from the developer-side accommodating portion 53a of the development unit 50 to the toner accommodating portion 71a of the toner cartridge 70.

[0080] When the rotary body 90 is in the above-described replenishment position, the toner contained in the toner container 71a is discharged from the discharge opening 71b and transported to the developer-side container 53a of the developing unit 50n through the receiving opening 53b. The toner contained in the developer-side container 53a is supplied to the developing roller 51. The toner contained in the toner container 71a is supplied to the developing roller 51 via this route.

[0081] (Toner cartridge partition) The toner filled in the toner cartridge 70 may become unevenly distributed within the toner cartridge 70 depending on the orientation of the toner cartridge during transportation and storage before it reaches the user. For example, as shown in FIG. 9 , if the toner cartridge 70 is transported with its longitudinal end (Y direction) facing downward, the toner inside the toner cartridge 70 will be unevenly distributed toward the end, i.e., toward the downstream side in the direction of gravity. Even if the toner cartridge 70 is returned to its intended use orientation in this state, the toner inside may remain unevenly distributed. When the toner inside is unevenly distributed, the amount of toner passing through the multiple discharge openings 71b arranged in the Y direction will differ, resulting in uneven toner supply to the development unit 50. If the toner supply to the development unit 50 becomes uneven in the Y direction, image defects such as low density in parts of the image area or blank areas where part of the image is not printed may occur.

[0082] Therefore, in this embodiment, by providing a partition 71p inside the toner cartridge 70, even if the toner inside the toner cartridge 70 becomes uneven due to logistics, etc., uneven toner supply from the multiple discharge openings 71b can be alleviated, and the occurrence of image defects such as low density and whiteouts can be suppressed.

[0083] The partition portion 71p in this embodiment will be described with reference to Figures 6(a) and 6(b). Figure 6(a) is a cross-sectional view showing a cross section perpendicular to the thickness direction (H direction) of the toner cartridge 70, and Figure 6(b) is a cross-sectional view showing a cross section perpendicular to the short side direction (R direction) of the toner cartridge 70.

[0084] Here, it is assumed that the toner cartridge 70 is projected in a first projection direction onto a first imaginary plane that is perpendicular to the first projection direction. In this case, the first projection direction that minimizes the projection area on the first imaginary plane can be called the longitudinal direction of the toner cartridge 70. Furthermore, as described above, when the toner cartridge 70 is attached to the rotary body 90, the longitudinal direction of the toner cartridge 70 is parallel to the direction of the rotation axis 90C of the rotary body 90 (the Y direction).

[0085] Furthermore, let us assume that the direction perpendicular to the first projection direction is the second projection direction, and that the toner cartridge 70 is projected in this second projection direction onto a second imaginary plane perpendicular to the second projection direction. In this case, the second projection direction that minimizes the projected area on the second imaginary plane can be referred to as the short-side direction of the toner cartridge 70. In other words, the short-side direction of the toner cartridge 70 is the direction perpendicular to the longitudinal direction of the toner cartridge 70. Furthermore, the direction perpendicular to the longitudinal and short-side directions of the toner cartridge 70 is referred to as the thickness direction of the toner cartridge 70.

[0086] In this embodiment, the longitudinal direction, lateral direction, and thickness direction of the toner frame 71 can be defined in the same way as the longitudinal direction, lateral direction, and thickness direction of the toner cartridge 70. In other words, the longitudinal direction, lateral direction, and thickness direction of the toner frame 71 are the same as the longitudinal direction, lateral direction, and thickness direction of the toner cartridge 70. Therefore, the longitudinal length of the toner cartridge 70 and the toner frame 71 is longer than the lateral length and the thickness length. Furthermore, the lateral length of the toner cartridge 70 and the toner frame 71 is longer than the thickness length.

[0087] In the following description, the longitudinal direction, lateral direction, and thickness direction of the toner frame 71 will not be distinguished from the longitudinal direction, lateral direction, and thickness direction of the toner cartridge 70, and will simply be referred to as the longitudinal direction, lateral direction, and thickness direction, respectively. Also, hereinafter, the longitudinal direction, lateral direction, and thickness direction of the toner cartridge 70 will be referred to as the Y direction, R direction, and H direction, respectively. Furthermore, as necessary, the Y direction, R direction, and H direction shown in each drawing will be referred to as the +Y side, +R side, and +H side, respectively, and the opposite sides will be referred to as the -Y side, -R side, and -H side, respectively. Furthermore, when the toner cartridge 70 is attached to the rotary body 90, the center of the rotation radius of the rotary body 90 is described as the -H side, and the outer side of the rotation radius is described as the +H side with respect to the rotation axis 90C of the rotary body 90.

[0088] 6(a) and 6(b), the toner frame 71 of the toner cartridge 70 of this embodiment has a plurality of discharge openings 71b, including six discharge openings 71bL11, 71bL12, 71bL13, 71bR11, 71bR12, and 71bR13. One of the discharge openings 71bL11, 71bL12, and 71bL13 is an example of a first discharge opening, and one of the discharge openings 71bR11, 71bR12, and 71bR13 is an example of a second discharge opening that is located at a different position in the Y direction from the first discharge opening.

[0089] The discharge openings 71bL11, 71bL12, and 71bL13 are located on the -Y side of the center 71c of the toner frame 71 in the Y direction. The discharge openings 71bR11, 71bR12, and 71bR13 are located on the +Y side of the center 71c of the toner frame 71. The multiple discharge openings 71b communicate with the corresponding receiving openings 53b of the developing units 50. When the rotary body 90 is in the above-mentioned replenishment position, the toner contained in the toner accommodating portion 71a is discharged from the discharge openings 71bL11, 71bL12, 71bL13, 71bR11, 71bR12, and 71bR13 and is contained in the developing-side accommodating portion 53a through the corresponding receiving openings 53b.

[0090] The toner frame 71 also has a partition 71p inside the toner storage portion 71a. The partition 71p is installed so as to divide the interior of the toner storage portion 71a into multiple spaces. In this embodiment, the partition 71p is installed so as to divide the interior of the toner storage portion 71a into a first space SP1 that communicates with the discharge openings 71bL11, 71bL12, and 71bL13, and a second space SP2 that communicates with the discharge openings 71bR11, 71bR12, and 71bR13. The first space SP1 and the second space SP2 are aligned in the Y direction, and the second space SP2 is a space separated from the first space SP1.

[0091] In this embodiment, the discharge openings 71bL11, 71bL12, and 71bL13 and the discharge openings 71bR11, 71bR12, and 71bR13 are arranged symmetrically in the Y direction around the center 71c, and the openings are arranged to be equal in size. Therefore, the partition 71p is arranged near the center 71c of the toner frame 71 so as to divide the toner storage section 71a into sections of approximately equal size. In other words, the volume of the first space SP1 and the volume of the second space SP2 are approximately equal. Note that the volumes of the first space SP1 and the second space SP2 do not necessarily have to be equal, but it is preferable that the volume of the first space SP1 be 80% to 120% of the volume of the second space SP2.

[0092] Furthermore, the partition 71p separates the toner storage section 71a so that the amount of toner stored in the first space SP1 and the amount of toner stored in the second space SP2 are approximately equal. This allows the amounts of toner supplied to the developer-side storage section 53a from the discharge openings 71bL11, 71bL12, and 71bL13 and the discharge openings 71bR11, 71bR12, and 71bR13 to be equal. Note that the amount of toner stored in the first space SP1 and the amount of toner stored in the second space SP2 do not necessarily have to be equal, but it is preferable that the amount of toner stored in the first space SP1 be 80% to 120% of the amount of toner stored in the second space SP2.

[0093] Next, the filling of toner into the toner cartridge 70 will be described with reference to Figures 7(a) and 7(b). Figure 7(a) is a cross-sectional view showing the toner cartridge 70 with the second frame 712 removed, and Figure 7(b) is a cross-sectional view showing the state in which the second frame 712 is attached to the first frame 711. In Figures 7(a) and 7(b), the state of the toner T is indicated by dots.

[0094] The toner frame 71 of the toner cartridge 70 is composed of a first frame 711 including a partition 71p and a second frame 712 including discharge openings 71bL11, 71bL12, 71bL13, 71bR11, 71bR12, and 71bR13. The first frame 711 is filled with toner T from a toner filling machine (not shown) through a nozzle 75. The nozzle 75 fills a predetermined amount of toner while moving in the Y direction. Thereafter, the second frame 712 is adhered to the first frame 711, and the toner T is sealed in. It is also preferable to stop the flow of toner T as it passes through the partition 71p to prevent the toner T from adhering to the partition 71p.

[0095] (Effects of Example 1) The effects of Example 1 will be described using the toner cartridge 70 of this example and a toner cartridge 700 as Comparative Example 1 that does not have a partition 71p. FIG. 8(a) is a cross-sectional view showing a cross section perpendicular to the thickness direction (H direction) of the toner cartridge 700 according to Comparative Example 1, and FIG. 8(b) is a cross-sectional view showing a cross section perpendicular to the short direction (R direction) of the toner cartridge 700. The toner cartridge 700 of Comparative Example 1 shown in FIGS. 8(a) and 8(b) has the same shape as the toner cartridge 70 of this example except that it does not have the partition 71p. That is, the toner cartridge 700 has discharge openings 71bL11, 71bL12, 71bL13, 71bR11, 71bR12, and 71bR13.

[0096] To demonstrate the effects of this embodiment, a comparative study was conducted using toner cartridges 70 of this embodiment and Comparative Example 1. A tapping test, described below, was conducted to simulate toner unevenness during transportation, and the occurrence of subsequent image defects was compared. For the tapping test, as shown in FIG. 9 , toner cartridges 70 and 700 were dropped from a height of 3 mm onto a hard platform with the -Y side facing downward at a speed of 125 times per minute. This was repeated 100 times, after which the toner cartridges 70 and 700 were installed in image forming apparatus 1, and 200 sheets of full-page blue images (100% magenta print + 100% cyan print image), in which low density and whiteout are easily visible, were printed. The images were checked every 50 sheets, and a good image was marked with an ◯, a low density with a △, and a whiteout with an ×. The results are shown in Table 1. [Table 1]

[0097] The state of the toner T in the toner cartridges of this embodiment and Comparative Example 1 when installed in the image forming apparatus 1 after the tapping test is shown in Figures 10(a) and 10(b) and Figures 11(a) and 11(b), respectively. In both toner cartridges 70 and 700, the bulk density of the toner in the toner storage section 71a becomes higher after the tapping test than when the toner was filled. As a result, the toner volume in the toner storage section 71a decreases to approximately 90% after tapping, assuming that the volume when the toner was filled is 100%. Hereinafter, the toner volume when the toner was filled is referred to as the "toner volume at filling," and the toner volume after tapping is referred to as the "toner volume after tapping." In other words, the toner volume after tapping is 90% of the toner volume when the toner was filled.

[0098] In the toner cartridge 700 of Comparative Example 1, as shown in Figure 11(a), the toner in the toner storage portion 71a is biased toward the -Y side. That is, the amount of toner on the side of the discharge openings 71bL11, 71bL12, and 71bL13 from the center portion 71c is 50% of the toner volume at the time of filling. On the other hand, the amount of toner on the side of the discharge openings 71bR11, 71bR12, and 71bR13 from the center portion 71c is 40% of the toner volume at the time of filling, which is less than the amount of toner on the side of the discharge openings 71bL11, 71bL12, and 71bL13 from the center portion 71c.

[0099] As printing progresses and the amount of toner in the toner storage section 71a decreases, the amount of toner on the discharge openings 71bR11, 71bR12, and 71bR13 side decreases, causing a shortage of toner supply from the discharge openings 71bR11, 71bR12, and 71bR13, as shown in Figure 11(b). Due to the shortage of toner supply, as shown in Table 1, low density occurred in part of the image on the discharge openings 71bR11, 71bR12, and 71bR13 side after 150 sheets were printed, and white spots occurred after 200 sheets were printed.

[0100] In contrast, in the toner cartridge 70 according to Example 1, the interior of the toner storage section 71a is divided by a partition 71p into a first space SP1 including discharge openings 71bL11, 71bL12, and 71bL13 and a second space SP2 including discharge openings 71bR11, 71bR12, and 71bR13. Therefore, as shown in FIG. 10A, during a tapping test, the toner T in the toner cartridge 70 is biased toward the -Y side in the first space SP1 and the second space SP2 separated by the partition 71p. However, because the interior of the toner storage section 71a is separated by the partition 71p, the toner volume after tapping in the first space SP1 and the toner volume after tapping in the second space SP2 are each 45% of the toner volume when the toner storage section 71a is filled. In other words, the amount of toner in the first space SP1 and the second space SP2 is equal even after tapping.

[0101] As a result, even if the amount of toner in the toner storage section 71a decreases as printing progresses, the toner supply from the discharge openings 71bL11, 71bL12, 71bL13, 71bR11, 71bR12, and 71bR13 is stabilized as shown in Fig. 10(b). Therefore, with the toner cartridge 70 according to Example 1, as shown in Table 1, no image defects such as low density or whiteout occurred even after printing 200 sheets, and good images were obtained.

[0102] As described above, by providing a partition 71p inside the toner cartridge 70, even if the toner in the toner storage section 71a becomes uneven due to logistics or the like, uneven toner supply can be alleviated, and the occurrence of image defects such as low density and white spots can be suppressed.

[0103] In this embodiment, the partition 71p divides the toner storage section 71a into a first space SP1 and a second space SP2, each of which includes three discharge openings. That is, a first number of three discharge openings 71bL11, 71bL12, and 71bL13 communicate with the first space SP1. Also, a second number of three discharge openings 71bR11, 71bR12, and 71bR13, which is the same as the first number, communicate with the second space SP2. This allows toner to be discharged in a balanced manner from the first space SP1 and the second space SP2.

[0104] The first space SP1 and the second space SP2 may be provided so as to communicate with different numbers of discharge openings. In other words, the partition 71p may divide the toner storage section 71a into the first space SP1 and the second space SP2 so as to communicate with different numbers of discharge openings. Even in such a case, for example, by making the sizes of the discharge openings different, the total area of ​​the discharge openings communicating with the first space SP1 and the total area of ​​the discharge openings communicating with the second space SP2 may be made substantially equal.

[0105] First Modification of First Embodiment Next, a toner cartridge 70A according to Modification 1 of Example 1 will be described with reference to Fig. 12(a). Fig. 12(a) is a cross-sectional view showing the internal structure of the toner cartridge 70A according to Modification 1 of Example 1. Note that in Modification 1, the same configurations as those in Example 1 will be omitted from the illustration or will be described with the same reference numerals in the drawings.

[0106] The toner cartridge 70A according to Modification 1 differs from the toner cartridge 70 according to Example 1 in the arrangement of the multiple discharge openings 71b and the partitions 71p. That is, the toner frame 71 of the toner cartridge 70A according to Modification 1 has multiple discharge openings 71b, including three discharge openings 71bL1, 71bC1, and 71bR1. In the toner cartridge 70A, the number of discharge openings 71b is reduced compared to Example 1, thereby reducing the area of ​​the discharge openings 71b in the toner frame 71 and increasing the strength, making the toner cartridge 70A less likely to deform.

[0107] The discharge opening 71bL1 is located on the -Y side of the central portion 71c of the toner frame 71 in the Y direction. The discharge opening 71bR1 is located on the +Y side of the central portion 71c. The discharge opening 71bC1 is positioned so as to overlap the central portion 71c. Each of the multiple discharge openings 71b communicates with the receiving openings 53b of the corresponding developing units 50.

[0108] The toner frame 71 also has partitions 71pL and 71pR inside the toner storage unit 71a. The partitions 71pL and 71pR are arranged to divide the interior of the toner storage unit 71a into multiple spaces. In this embodiment, the partitions 71pL and 71pR are arranged to divide the interior of the toner storage unit 71a into a first space SP11 that communicates with the discharge opening 71bL1, a second space SP12 that communicates with the discharge opening 71bC1, and a third space SP13 that communicates with the discharge opening 71bR1.

[0109] In this first modification, too, the partitions 71pL and 71pR divide the toner storage section 71a into a first space SP11, a second space SP12, and a third space SP13 so that each space communicates with at least one discharge opening. More specifically, the first space SP11, the second space SP12, and the third space SP13 each communicate with the same number of discharge openings (one in the first modification). This makes it possible to alleviate uneven toner supply even if the toner in the toner storage section 71a becomes uneven due to logistics or the like, thereby suppressing the occurrence of image defects such as low density and white voids.

[0110] Second Modification of First Embodiment Next, a toner cartridge 70B according to Modification 2 of Example 1 will be described with reference to Fig. 12(b). Fig. 12(b) is a cross-sectional view showing the internal structure of the toner cartridge 70B according to Modification 2 of Example 1. Note that in Modification 2, the same configurations as those in Example 1 will be omitted from the illustration or will be described with the same reference numerals in the drawings.

[0111] The toner cartridge 70B according to Modification 2 differs from the toner cartridge 70 according to Example 1 in the number and arrangement of the partitions 71p. That is, the toner frame 71 of the toner cartridge 70B according to Modification 2 has five partitions 71p11, 71p12, 71p13, 71p14, and 71p15 inside the toner storage section 71a. The partitions 71p11, 71p12, 71p13, 71p14, and 71p15 are installed so as to divide the interior of the toner storage section 71a into multiple spaces. In this embodiment, the partitions 71p11, 71p12, 71p13, 71p14, and 71p15 are arranged to divide the interior of the toner storage section 71a into a first space SP21 communicating with the discharge opening 71bL11, a second space SP22 communicating with the discharge opening 71bL12, a third space SP23 communicating with the discharge opening 71bL13, a fourth space SP24 communicating with the discharge opening 71bR13, a fifth space SP25 communicating with the discharge opening 71bR12, and a sixth space SP26 communicating with the discharge opening 71bR11.

[0112] In the present modified example 2, the partitions 71p11, 71p12, 71p13, 71p14, and 71p15 also divide the toner storage section 71a into a first space SP21, a second space SP22, a third space SP23, a fourth space SP24, a fifth space SP25, and a sixth space SP26 so that each space communicates with at least one discharge opening. More specifically, the first space SP21, the second space SP22, the third space SP23, the fourth space SP24, the fifth space SP25, and the sixth space SP26 each communicate with the same number of discharge openings (one in the modified example 1). This makes it possible to alleviate uneven toner supply even if the toner in the toner storage section 71a becomes uneven due to logistics or the like, thereby suppressing the occurrence of image defects such as low density and white voids.

[0113] Furthermore, in the toner cartridge 70B according to the second modification, the number of partitions is increased compared to that in the first embodiment, and the space inside the toner containing portion 71a is partitioned into many partitions, thereby making it possible to further reduce the influence of uneven toner distribution.

[0114] On the other hand, by increasing the number of partitions that separate the toner storage compartment 71a as in the above-described modified examples 1 and 2, the amount of space other than the partitions in the toner storage compartment 71a is reduced, which reduces the amount of toner that can be filled into the toner cartridge. It is desirable to select an optimal number of partitions based on the balance between the size of the toner cartridge in the image forming device 1 and the required amount of toner.

[0115] Example 2 Next, a toner cartridge 70C according to Example 2 will be described, in which the number and arrangement of the discharge openings 71b in Example 1 are changed. Therefore, the same components as those in Example 1 will be omitted from the illustration or will be described by using the same reference numerals in the drawings. Fig. 13(a) is a cross-sectional view showing the toner cartridge 70C according to Example 2, and Fig. 13(b) is a cross-sectional view showing the positional relationship between the toner cartridge 70C and the scanner 4.

[0116] 13(a), a partition 71p is provided inside the toner cartridge 70C, similar to Example 1. The partition 71p is provided in the center 71c in the Y direction of the toner frame 71, and divides the toner storage section 71a into a first space SP1 and a second space SP2.

[0117] The toner frame 71 of the toner cartridge 70C of this embodiment has a plurality of discharge openings 71b, including two discharge openings 71bL and 71bR. The discharge opening 71bL, serving as a first discharge opening, communicates with the first space SP1 and is located at the end of the toner frame 71 on the -Y side. The discharge opening 71bR, serving as a second discharge opening, communicates with the second space SP2 and is located at the end of the toner frame 71 on the +Y side. That is, the discharge openings 71bL and 71bR are located at one end and the other end of the toner frame 71 in the Y direction, respectively. The discharge openings 71bL and 71bR communicate with the receiving openings 53b of the corresponding developing units 50.

[0118] In the first embodiment, multiple discharge openings 71b are also arranged on the side of the central portion 71c of the toner cartridge 70 in the Y direction. As described above, the toner cartridge 70 is movable between an attached position and a retracted position with respect to the developing frame 53 of the developing unit 50. When the toner cartridge 70 is in the attached position with respect to the developing frame 53, the discharge opening 71b faces the receiving opening 53b of the developing unit 50. At this time, the discharge opening 71b is sealed by a sealing member (not shown) to prevent toner from leaking out of the receiving opening 53b of the developing unit 50.

[0119] Similarly, when the toner cartridge 70 is in the retracted position relative to the developing frame 53, the discharge opening 71b is sealed by a sealing member (not shown) to prevent toner from leaking out of the receiving opening 53b of the developing unit 50. However, there is a possibility that a small amount of toner may leak out of the discharge opening 71b due to the replacement operation of the toner cartridge 70 and the rotation operation of the rotary body 90.

[0120] Such toner is usually not a problem because the amount is so small. However, if the image forming apparatus 1 is designed to have a long life, repeated replacement of the toner cartridge 70 can cause toner leaking from the discharge opening 71b to accumulate below the discharge opening 71b in the direction of gravity (the -Z direction). In the image forming apparatus 1 shown in FIG. 1, the scanner 4 is disposed in the -Z direction relative to the toner cartridge 70, i.e., below the direction of gravity. Therefore, as image formation operations are repeated and the number of printed pages increases, toner leaking from the toner cartridge 70 can accumulate on the scanner 4, contaminating the scanner 4. In an image forming apparatus designed for a long life, measures must be taken to prevent the scanner 4 from becoming contaminated, such as installing a cover glass over the scanner 4 opening and providing a cleaning tool for when the cover glass becomes contaminated by toner accumulation. This increases costs and the size of the image forming apparatus 1 due to the complex mechanism.

[0121] FIG. 14(a) is a cross-sectional view showing a toner cartridge 700B according to Comparative Example 2, and FIG. 14(b) is a cross-sectional view showing the positional relationship between the toner cartridge 700B and the scanner 4. As shown in FIGS. 14(a) and 14(b), in the toner cartridge 700B according to Comparative Example 2, similar to Example 2, a discharge opening 71bL is disposed at the -Y side end of the toner frame 71, and a discharge opening 71bR is disposed at the +Y side end of the toner frame 71. These discharge openings 71bL and 71bR are disposed so as not to overlap with the scanner 4 in the Y direction. In other words, in the Y direction, the positions of the discharge openings 71bL and 71bR (the range in which the discharge openings 71bL and 71bR exist) do not overlap with the position of the scanner 4 (the range in which the scanner 4 exists). In other words, when the discharge openings 71bL and 71bR and the scanner 4 are vertically projected in a direction perpendicular to the Y direction, the projection areas of the discharge openings 71bL and 71bR and the projection area of ​​the scanner 4 do not overlap with each other in the Y direction.

[0122] The configuration of Comparative Example 2 as described above can suppress toner contamination of the scanner 4. However, if the discharge openings 71bL and 71bR are provided at both ends of the toner storage section 71a in the Y direction, toner located far from the discharge openings 71bL and 71bR is difficult to discharge. In particular, if the toner inside is unevenly distributed in the Y direction due to logistics or the like, the amount of toner passing through the multiple discharge openings 71b is more likely to vary compared to when the discharge openings 71b are provided across the entire area in the Y direction, resulting in more uneven toner supply to the developing unit 50. This can result in image defects such as low image density in part of the image area or blank areas where part of the image is not printed.

[0123] To address the above-mentioned issues, in this embodiment, as shown in FIGS. 13(a) and 13(b), a partition 71p is provided inside the toner cartridge 70C. This prevents uneven toner distribution within the first space SP1 and the second space SP2, even when the discharge openings 71bL and 71bR are located at both ends of the toner storage section 71a in the Y direction. Therefore, even if the toner distribution within the toner cartridge 70C is uneven due to logistics or other reasons, uneven toner supply from the multiple discharge openings 71bL and 71bR can be alleviated, thereby preventing image defects such as low density and white areas. The positional relationship between the discharge openings 71bL and 71bR and the scanner 4 in Example 2 is the same as that in Comparative Example 2 shown in FIG. 14(b). That is, as shown in FIG. 13(b), the discharge openings 71bL and 71bR in Example 2 are positioned so as not to overlap with the scanner 4 in the Y direction.

[0124] The partition 71p is provided in the central portion 71c of the toner frame 71 in the Y direction, and divides the toner storage portion 71a into a first space SP1 and a second space SP2, as in the first embodiment. In this embodiment, the discharge openings 71bL and 71bR are arranged symmetrically in the longitudinal direction (Y direction) around the central portion 71c, and the openings are arranged to have the same size. That is, the partition 71p divides the toner storage portion 71a so that the volumes of the first space SP1 and the second space SP2 are approximately equal, and so that the amount of toner stored in the first space SP1 and the amount of toner stored in the second space SP2 are approximately equal. This makes it possible to equalize the amount of toner supplied from the discharge opening 71bL and the discharge opening 71bR to the developer-side storage portion 53a.

[0125] (Effects of Example 2) The effects of Example 2 will be explained using toner cartridge 70C of this example and toner cartridge 700B as Comparative Example 2, which does not have partition portion 71p. Toner cartridge 700B of Comparative Example 2, shown in Figures 14(a) and 14(b), has the same shape as toner cartridge 70C of Example 2, except that it does not have partition portion 71p.

[0126] To demonstrate the effects of this embodiment, a comparative study was conducted using toner cartridges of this embodiment and Comparative Example 2. A tapping test, described below, was conducted to simulate toner unevenness during transportation, and the occurrence of subsequent image defects was compared. For the tapping test, as shown in FIG. 9 , toner cartridges 70C and 700B were dropped from a height of 3 mm onto a hard table with the -Y side facing downward at a speed of 125 times per minute. This was repeated 100 times, and then toner cartridges 70C and 700B were installed in image forming apparatus 1, and 200 sheets of full-blue images (100% magenta print + 100% cyan print image), in which low density and whiteout are easily visible, were printed. The images were checked every 50 sheets, and a good image was marked with an ◯, a low density with a △, and a whiteout with an ×. The results are shown in Table 2. [Table 2]

[0127] The state of the toner T in the toner cartridges of this embodiment and Comparative Example 2 when they are installed in the image forming apparatus 1 after the tapping test is shown schematically in Figures 15(a) and 15(b) and Figures 16(a) and 16(b), respectively. In both toner cartridges 70C and 700B, the bulk density of the toner in the toner storage section 71a becomes higher after the tapping test than when the toner was filled. As a result, the toner volume occupying the toner storage section 71a decreases to about 90% after tapping, assuming that the volume when the toner was filled is 100%.

[0128] 16(a), in the toner cartridge 700B of Comparative Example 2, the toner in the toner storage portion 71a is biased toward the -Y side. That is, the amount of toner on the side of the discharge opening 71bL relative to the central portion 71c is 50% of the toner volume at the time of filling. On the other hand, the amount of toner on the side of the discharge opening 71bR relative to the central portion 71c is 40% of the toner volume at the time of filling, which is less than the amount of toner on the side of the discharge opening 71bL relative to the central portion 71c.

[0129] As printing progresses and the amount of toner in the toner storage section 71a decreases, the amount of toner on the discharge opening 71bR side decreases, causing a shortage of toner supply from the discharge opening 71bR, as shown in Figure 16(b). Due to the shortage of toner supply, as shown in Table 2, low density occurred in part of the image on the discharge opening 71bR side after 100 sheets were printed, and whiteouts occurred after 150 and 200 sheets were printed.

[0130] In contrast, in the toner cartridge 70C according to Example 2, the interior of the toner storage section 71a is divided by a partition 71p into a first space SP1 including the discharge opening 71bL and a second space SP2 including the discharge opening 71bR. Therefore, as shown in FIG. 15A, during a tapping test, the toner T in the toner cartridge 70 is biased toward the -Y side in each of the first and second spaces SP1 and SP2 separated by the partition 71p. However, because the interior of the toner storage section 71a is separated by the partition 71p, the toner volume in the first space SP1 and the toner volume in the second space SP2 after tapping are each 45% of the toner volume when the toner storage section 71a is filled. In other words, the amount of toner in the first space SP1 and the second space SP2 is equal even after tapping.

[0131] As a result, even if the amount of toner in the toner storage section 71a decreases as printing progresses, the toner supply from the discharge openings 71bL and 71bR is stabilized as shown in Fig. 15(b). Therefore, with the toner cartridge 70C according to Example 2, as shown in Table 2, no image defects such as low density or whiteout occurred even after printing 200 sheets, and good images were obtained.

[0132] As described above, by arranging the discharge openings 71bL and 71bR at both ends of the toner storage section 71a in the Y direction so as not to overlap with the scanner 4 in the Y direction, it is possible to prevent the scanner 4 from being soiled with toner.

[0133] Furthermore, by providing the partition 71p inside the toner cartridge 70, even if the toner in the toner storage section 71a becomes uneven due to logistics, etc., the amount of toner in the first space SP1 and the second space SP2 can be made approximately equal. Furthermore, even if the discharge openings 71bL, 71bR are located at both ends of the toner storage section 71a in the Y direction, it is possible to alleviate uneven toner supply from the discharge openings 71bL, 71bR, and prevent image defects such as low density and white voids from occurring.

[0134] Example 3 Next, a toner cartridge 70D according to Example 3 will be described. Example 3 is configured by providing a plurality of guide portions 71g in the first space SP1 and the second space SP2 of Example 2. Therefore, the same configuration as in Example 2 will be omitted from the illustration or will be described by using the same reference numerals in the drawings. Fig. 17(a) is a cross-sectional view showing a cross section perpendicular to the thickness direction (H direction) of the toner cartridge 70D according to Example 3, and Fig. 17(b) is a cross-sectional view showing a cross section perpendicular to the short side direction (R direction) of the toner cartridge 70D.

[0135] 17(a), the toner cartridge 70D according to this embodiment has a toner frame 71 composed of a first frame 711 and a second frame 712. The first frame 711 is provided with a partition 71p, as in the second embodiment. The second frame 712 is adhered to the first frame 711, so that the partition 71p divides the toner storage section 71a into a first space SP1 and a second space SP2. The partition 71p is provided in a center portion 71c of the toner frame 71 in the Y direction.

[0136] The toner frame 71 of the toner cartridge 70D of this embodiment also has two discharge openings 71bL and 71bR. The discharge opening 71bL communicates with the first space SP1 and is located at the end of the toner frame 71 on the -Y side. The discharge opening 71bR communicates with the second space SP2 and is located at the end of the toner frame 71 on the +Y side. The discharge openings 71bL and 71bR communicate with the receiving openings 53b of the corresponding developing units 50.

[0137] 17(a) and 17(b), the second frame 712 of the toner frame 71 has a plurality of guide portions 71g that guide the toner contained in the toner containing portion 71a. In this embodiment, the plurality of guide portions 71g include a plurality of left guides 71gL as first guide portions and a plurality of right guides 71gR as second guide portions. The left guides 71gL extend in the -Y direction as they extend in the -R direction, and the right guides 71gR extend in the +Y direction as they extend in the -R direction. In other words, the left guides 71gL and the right guides 71gR extend at an angle relative to the R and Y directions.

[0138] The left guide 71gL is disposed between the partition 71p (or the central portion 71c) and the discharge opening 71bL in the Y direction, and is disposed with a gap from the inner wall of the toner frame 71 in the R direction. The right guide 71gR is disposed between the partition 71p (or the central portion 71c) and the discharge opening 71bR in the Y direction, and is disposed with a gap from the inner wall of the toner frame 71 in the R direction. The left guide 71gL and the right guide 71gR are also disposed with a gap from the inner wall of the toner frame 71 in the H direction, and the gap is preferably about half the distance between the frame 711 and the frame 712.

[0139] The left guide 71gL guides toner that moves under its own weight toward the discharge opening 71bL provided on the -Y side as the rotary body 90 (described later) rotates. The right guide 71gR guides toner that moves under its own weight toward the discharge opening 71bR provided on the +Y side. Note that the left guide 71gL and the discharge opening 71bL are symmetrical in the Y direction with respect to the right guide 71gR and the discharge opening 71bR, but this does not have to be a perfect symmetry. Furthermore, the number of left guides 71gL and the number of right guides 71gR may be different.

[0140] (Guidance of toner to the discharge opening by the guide portion) 20 and 21(a, b) will be used to explain the movement of toner accompanying the rotation of the rotary body 90. Fig. 20 is a schematic view of the toner cartridge 70D rotating about the rotation axis 90C, viewed in the Y direction. Figs. 21(a, b) are schematic views showing the internal structure of the toner cartridge 70D in the longitudinal direction (Y direction) at positions Tp3 and Tp7 in Fig. 20, respectively.

[0141] 20, the rotary body 90 rotates clockwise (in the direction of arrow R2). When the toner cartridge 70D rotates once from position Tp0, the toner cartridge 70D moves to positions Tp0, Tp1, Tp2, Tp3, Tp4, Tp5, Tp6, and Tp7 in that order, before returning to position Tp0.

[0142] The rotary body 90 assumes the replacement position described above when replacing the toner cartridge 70D at position Tp2. The toner cartridge 70D at position Tp2 is being attached to or detached from the rotary body 90. When the toner cartridge 70D rotates from position Tp2 to position Tp4, gravity acts on the toner, causing the toner in the toner cartridge 70D to move along the frame 711 of the toner cartridge 70D. For example, when the toner cartridge 70D is at position Tp3, as shown in FIG. 21(a), the toner moves within the toner storage section 71a. Because there is a gap between the frame 711 and the multiple guide portions 71g in the H direction, most of the toner in the toner storage section 71a is not affected by the guide portions 71g and moves only in the +R direction, as indicated by arrow G1, and does not move in the Y direction.

[0143] Furthermore, when the toner cartridge 70D rotates from position Tp6 to position Tp0, gravity acts on the toner, causing the toner in the toner cartridge 70D to move along the frame 712 of the toner cartridge 70D. For example, when the toner cartridge 70D is at position Tp7, as shown in FIG. 21(b), the toner moves within the toner storage section 71a. Because multiple guide portions 71g are arranged on the frame 712, the toner moves along the guide portions 71g in the -R direction and the ±Y directions, as indicated by arrows G2. Furthermore, because there is a gap between the frame 712 and the guide portions 71g in the R direction, the toner that moves along the guide portions 71g in the -R direction can move toward the discharge openings 71b (71bL, 71bR) in the ±Y directions, as indicated by arrows G3.

[0144] By repeating the above operation, the toner in the toner storage section 71a is guided by the guide section 71g to the discharge openings 71bL and 71bR. In this way, by utilizing the rotation of the rotary body 90 and without using a stirring member, even toner located far from the discharge openings 71bL and 71bR can be efficiently supplied to the developer-side storage section 53a.

[0145] If the toner contained in the toner storage unit 71a is left in a hot and humid environment for a long period of time after the sealing members (not shown) are removed from the discharge openings 71bL and 71bR, the fluidity of the toner deteriorates. In this state, toner located away from the discharge openings 71bL and 71bR is difficult to discharge, and there is a risk that toner may remain in the toner storage unit 71a. However, the toner cartridge 70D of this embodiment is provided with multiple guide portions 71g that guide the toner in the toner storage unit 71a to the discharge openings 71bL and 71bR as the rotary body 90 rotates, thereby improving the dischargeability of toner.

[0146] Next, filling of toner into toner cartridge 70D will be described with reference to Figures 19(a) and 19(b). Figure 19(a) is a cross-sectional view showing toner cartridge 70D with second frame 712 removed, and Figure 19(b) is a cross-sectional view showing the state in which second frame 712 is attached to first frame 711. In Figures 19(a) and 19(b), the state of toner T is indicated by dots.

[0147] The toner frame 71 of the toner cartridge 70D is composed of a first frame 711 including a partition 71p and a second frame 712 including discharge openings 71bL, 71bR and a plurality of guide portions 71g. The first frame 711 is filled with toner T from a toner filling machine (not shown) through a nozzle 75. The nozzle 75 fills a predetermined amount of toner while moving in the Y direction. Thereafter, the second frame 712 is adhered to the first frame 711, and the toner T is sealed in. It is also preferable to stop the flow of toner T as it passes through the partition 71p to prevent the toner T from adhering to the partition 71p.

[0148] (Effects of Example 3) The effects of Example 3 will be explained using toner cartridge 70D of this example and toner cartridge 700C as Comparative Example 3, which does not have partition portion 71p. Toner cartridge 700C of Comparative Example 3 shown in Figures 18(a) and 18(b) has the same shape as toner cartridge 70D of Example 3, except that it does not have partition portion 71p.

[0149] To demonstrate the effectiveness of this example, a comparative study was conducted using toner cartridges from this example, Comparative Example 2, and Comparative Example 3. A tapping test, described below, was conducted to simulate toner unevenness during transportation, and the occurrence of subsequent image defects was compared. For the tapping test, as shown in FIG. 9 , toner cartridges 70D and 700C were dropped from a height of 3 mm onto a hard platform with the -Y side facing downward at a speed of 125 times per minute. This was repeated 100 times, after which toner cartridges 70D and 700C were installed in image forming apparatus 1, and 200 sheets of full-page blue images (100% magenta print + 100% cyan print image), in which low density and whiteout are easily visible, were printed. The images were checked every 50 sheets, and a good image was marked with an ◯, a low density with a △, and a whiteout with an ×. The results are shown in Table 3. [Table 3]

[0150] The state of the toner T in the toner cartridges of this embodiment, Comparative Example 2, and Comparative Example 3 when they are installed in the image forming apparatus 1 after the tapping test is shown schematically in Figures 22(a) and 22(b), 16(a) and 16(b), and 23(a) and 23(b), respectively. In all of toner cartridges 70D, 700B, and 700C, the bulk density of the toner in the toner storage section 71a becomes higher after the tapping test than when the toner was filled. As a result, the toner volume occupying the toner storage section 71a, assuming it is 100% when filled with toner, decreases to about 90% after tapping.

[0151] In the toner cartridges 700B and 700C of Comparative Examples 2 and 3, the toner in the toner storage portion 71a is biased toward the -Y side, as shown in Figures 16(a) and 23(a). That is, the amount of toner on the side of the discharge opening 71bL relative to the central portion 71c is 50% of the toner volume at the time of filling. On the other hand, the amount of toner on the side of the discharge opening 71bR relative to the central portion 71c is 40% of the toner volume at the time of filling, which is less than the amount of toner on the side of the discharge opening 71bL relative to the central portion 71c.

[0152] In Comparative Example 2, as printing progresses and the amount of toner in the toner storage section 71a decreases, the amount of toner on the discharge opening 71bR side decreases, causing a shortage of toner supply from the discharge opening 71bR, as shown in Figure 16(b). Due to the shortage of toner supply, as shown in Table 3, low density occurred in part of the image on the discharge opening 71bR side after 100 sheets were printed, and white spots occurred after 150 and 200 sheets were printed.

[0153] Furthermore, in Comparative Example 3, multiple guide portions 71g are provided in the toner storage portion 71a. Therefore, the toner in the toner storage portion 71a can be guided to the discharge openings 71bL and 71bR as the rotary body 90 rotates. Therefore, image defects are less likely to occur compared to Comparative Example 2. However, as shown in Table 3, low density occurred in part of the image on the discharge opening 71bR side after 200 sheets were printed.

[0154] In contrast, the toner cartridge 70D according to Example 3 has a toner storage compartment 71a divided by a partition 71p into a first space SP1 including a discharge opening 71bL and a second space SP2 including a discharge opening 71bR. Furthermore, multiple guide members 71g are provided within the toner storage compartment 71a of the toner cartridge 70D. Therefore, as shown in FIG. 22(a), during a tapping test, the toner T in the toner cartridge 70 is biased toward the -Y side in the first space SP1 and the second space SP2 separated by the partition 71p. However, because the toner storage compartment 71a is separated by the partition 71p, the toner volume in the first space SP1 and the second space SP2 after tapping is 45% of the toner volume when the toner storage compartment 71a is filled. That is, the toner amount in the first space SP1 and the toner amount in the second space SP2 are equal even after tapping. Furthermore, the plurality of guide portions 71g can guide the toner in the toner storage portion 71a to the discharge openings 71bL and 71bR as the rotary body 90 rotates.

[0155] As a result, even if the amount of toner in the toner storage section 71a decreases as printing progresses, the toner supply from the discharge openings 71bL and 71bR is stabilized as shown in Fig. 22(b). Therefore, with the toner cartridge 70D according to Example 3, as shown in Table 3, no image defects such as low density or whiteout occurred even after printing 200 sheets, and good images were obtained.

[0156] As described above, by providing the partition 71p inside the toner cartridge 70, even in a situation where the toner in the toner storage portion 71a is unevenly distributed and the toner fluidity deteriorates due to logistics or the like, the amount of toner in the first space SP1 and the second space SP2 can be made approximately equal. Furthermore, even if the discharge openings 71bL, 71bR are located at both ends of the toner storage portion 71a in the Y direction, it is possible to alleviate uneven toner supply from the discharge openings 71bL, 71bR, and prevent image defects such as low density and white voids from occurring.

[0157] Although the multiple guide portions 71g in this embodiment are provided on the second frame 712, the present invention is not limited to this and they may be provided on the first frame 711. In this case, the guide portions 71g may be arranged not only on the inner wall of the end portion in the H direction of the first frame 711 but also on the inner wall of the end portion in the R direction. Furthermore, the guide portions 71g may be provided on both the first frame 711 and the second frame 712. In either case, the guide portions 71g only need to be configured to guide toner that moves due to its own weight as the rotary body 90 rotates, toward the discharge openings 71b (discharge openings 71bL, 71bR).

[0158] <<Modification of the Third Embodiment>> In the third embodiment described above, the partition 71p is formed to have a rectangular cross section when viewed in the R direction, but this is not limiting. For example, as shown in Figures 24(a) and 24(b), the partition 71p may be formed to have inclined surfaces 71q1 and 71q2. The inclined surface 71q1, which serves as a first guide surface, is disposed on the first space SP1 side, and the inclined surface 71q2, which serves as a second guide surface, is disposed on the second space SP2 side.

[0159] The inclined surfaces 71q1 and 71q2 have the same inclination as the left guide 71gL and the right guide 71gR, respectively. The inclined surface 71q1 extends in the -Y direction as it approaches the -R direction, and the inclined surface 71q2 extends in the +Y direction as it approaches the -R direction. That is, the inclined surfaces 71q1 and 71q2 extend at an angle with respect to the R direction and the Y direction. This allows the inclined surfaces 71q1 and 71q2 to have the same function as the guide portion 71g, and to more efficiently guide toner moving under its own weight toward the discharge opening 71b (discharge openings 71bL and 71bR).

[0160] Other Embodiments In addition, in all of the above-described embodiments, a rotary development type image forming apparatus has been described as an example of the image forming apparatus 1, but the present invention is not limited to this type. In other words, if the image forming apparatus uses a toner replacement type in which the toner cartridge is replaced, the same effect can be obtained by using the toner cartridge of the present invention.

[0161] In addition, in all of the above-described embodiments, the sizes of the multiple discharge openings 71b are the same, and therefore the sizes of the spaces separated by the partitions and the number of discharge openings 71b communicating with these spaces are the same, but the present invention is not limited to this. Depending on the sizes of the discharge openings 71b and the arrangement of the discharge openings 71b in the Y direction, the multiple spaces separated by the partitions 71p may be different sizes. Furthermore, it is sufficient that the multiple spaces are separated so that each includes at least one of the multiple discharge openings 71b.

[0162] In addition, in all of the above-described embodiments, one partition (71p) has the function of dividing one space into two spaces, but this is not limited to this. For example, by forming the partition with a V-shaped cross section, one partition may be configured to divide one space into three spaces. In this way, the number of spaces divided by one partition is not limited.

[0163] Summary of the Disclosure The present disclosure includes at least the following: (Configuration 1) A toner cartridge detachably attached to a development unit having a development roller, a frame extending in a longitudinal direction, the frame including: a storage chamber for storing toner; a first discharge port provided in the frame so as to communicate with the storage chamber, through which toner passes when discharged from the storage chamber to the developing unit; and a second discharge port provided in the frame so as to communicate with the storage chamber, located at a position different from the first discharge port in the longitudinal direction, through which toner passes when discharged from the storage chamber to the developing unit; a partition portion that divides the storage chamber into a plurality of spaces including a first space and a second space separated from the first space, the first outlet communicates with the first space, The second outlet communicates with the second space. A toner cartridge characterized by: (Configuration 2) The first space and the second space are aligned in the longitudinal direction. 2. The toner cartridge according to claim 1, (Configuration 3) The first discharge port is disposed at one end of the frame in the longitudinal direction, The second discharge port is disposed at the other end of the frame in the longitudinal direction. 3. The toner cartridge according to claim 2. (Configuration 4) The partition portion is disposed in the center portion of the frame body in the longitudinal direction. 4. The toner cartridge according to configuration 2 or 3. (Configuration 5) a first guide portion disposed in the first space, the first guide portion guiding the toner contained in the first space and moving due to its own weight toward the first discharge port; a second guide portion disposed in the second space, the second guide portion guiding the toner contained in the second space and moving due to its own weight toward the second discharge port; 5. The toner cartridge according to any one of configurations 1 to 4. (Configuration 6) The first guide portion and the second guide portion are each provided so as to be inclined with respect to the longitudinal direction. 6. The toner cartridge according to configuration 5. (Configuration 7) The partition portion includes a first guide surface that guides the toner contained in the first space and moving due to its own weight toward the first discharge outlet, and a second guide surface that guides the toner contained in the second space and moving due to its own weight toward the second discharge outlet. 7. The toner cartridge according to any one of configurations 1 to 6. (Configuration 8) The amount of toner contained in the first space is 80% to 120% of the amount of toner contained in the second space. 8. The toner cartridge according to any one of configurations 1 to 7. (Configuration 9) The volume of the first space is 80% to 120% of the volume of the second space. 9. The toner cartridge according to any one of configurations 1 to 8. (Configuration 10) an apparatus main body including a photosensitive drum and the developing unit; and a toner cartridge according to any one of configurations 1 to 9. An image forming apparatus characterized by: (Configuration 11) the apparatus main body includes an exposure device that exposes the surface of the photosensitive drum to light to form an electrostatic latent image on the surface; the first discharge opening and the second discharge opening are arranged so as not to overlap the exposure device in the longitudinal direction when the toner cartridge is attached to the developing unit. 11. The image forming apparatus according to claim 10, (Configuration 12) the apparatus main body includes a rotary that rotatably supports the developing unit; 12. The image forming apparatus according to claim 10 or 11. (Configuration 13) The rotation axis of the rotary extends in the longitudinal direction. 13. The image forming apparatus according to configuration 12. (Configuration 14) A toner cartridge detachably attached to a development unit having a development roller, a frame extending in a longitudinal direction, the frame including a storage chamber for storing toner, and a plurality of discharge ports provided in the frame so as to communicate with the storage chamber, arranged side by side in the longitudinal direction, through which toner passes when discharged from the storage chamber to the developing unit; a partition portion that divides the storage chamber into a plurality of spaces, The plurality of spaces each communicate with at least one of the plurality of exhaust ports. A toner cartridge characterized by: (Configuration 15) each of the plurality of spaces contains toner, and includes a first space separated by the partition portion and a second space separated from the first space; Among the plurality of outlets, a first number of outlets communicate with the first space; Among the plurality of exhaust ports, a second number of exhaust ports, which is the same as the first number, communicate with the second space. 15. The toner cartridge according to claim 14. (Configuration 16) an apparatus main body including a photosensitive drum and the developing unit; The toner cartridge according to configuration 14 or 15, An image forming apparatus characterized by: (Configuration 17) the apparatus main body includes a rotary that rotatably supports the developing unit; 17. The image forming apparatus according to claim 16, (Configuration 18) The rotation axis of the rotary extends in the longitudinal direction. 18. The image forming apparatus according to configuration 17. [Explanation of symbols]

[0164] 1: Image forming apparatus / 1A: Apparatus main body / 2: Photosensitive drum / 4: Exposure device (scanner) / 50: Development unit / 51: Development roller / 70, 70A, 70B, 70C, 70D, 70E: Toner cartridge / 71: Frame (toner frame) / 71a: Storage chamber (toner storage section) / 71bL: First discharge port (discharge opening) / 71bL11, 71bL12, 71bL13: First discharge port (discharge opening) / 71bR: Second discharge port ( Discharge opening) / 71bR11, 71bR12, 71bR13: Second discharge port (discharge opening) / 71c: Center section / 71gL: First guide section (left guide) / 71gR: Second guide section (right guide) / 71p: Partition section / 71q1: First guide surface (inclined surface) / 71q2: Second guide surface (inclined surface) / 90: Rotary (rotary body) / 90C: Rotation axis / SP1: First space / SP2: Second space / Y: Longitudinal direction (direction)

Claims

1. A toner cartridge detachably attached to a development unit having a development roller, a frame extending in a longitudinal direction, the frame including: a storage chamber for storing toner; a first discharge port provided in the frame so as to communicate with the storage chamber, through which toner passes when discharged from the storage chamber to the developing unit; and a second discharge port provided in the frame so as to communicate with the storage chamber, located at a position different from the first discharge port in the longitudinal direction, through which toner passes when discharged from the storage chamber to the developing unit; a partition portion that divides the storage chamber into a plurality of spaces including a first space and a second space separated from the first space, the first outlet communicates with the first space, The second outlet communicates with the second space. A toner cartridge characterized by:

2. The first space and the second space are aligned in the longitudinal direction.

2. The toner cartridge according to claim 1, wherein the toner cartridge is a toner cartridge having a toner cartridge.

3. The first discharge port is disposed at one end of the frame in the longitudinal direction, The second discharge port is disposed at the other end of the frame in the longitudinal direction.

3. The toner cartridge according to claim 2.

4. The partition portion is disposed in the center portion of the frame body in the longitudinal direction.

3. The toner cartridge according to claim 2.

5. a first guide portion disposed in the first space, the first guide portion guiding the toner contained in the first space and moving due to its own weight toward the first discharge port; a second guide portion disposed in the second space, the second guide portion guiding the toner contained in the second space and moving due to its own weight toward the second discharge port; 2. The toner cartridge according to claim 1, wherein the toner cartridge is a toner cartridge having a toner cartridge.

6. The first guide portion and the second guide portion are each provided so as to be inclined with respect to the longitudinal direction.

6. The toner cartridge according to claim 5.

7. The partition portion includes a first guide surface that guides the toner contained in the first space and moving due to its own weight toward the first discharge outlet, and a second guide surface that guides the toner contained in the second space and moving due to its own weight toward the second discharge outlet.

2. The toner cartridge according to claim 1, wherein the toner cartridge is a toner cartridge having a toner cartridge.

8. the amount of toner contained in the first space is 80% to 120% of the amount of toner contained in the second space; 2. The toner cartridge according to claim 1, wherein the toner cartridge is a toner cartridge having a toner cartridge.

9. The volume of the first space is 80% to 120% of the volume of the second space.

2. The toner cartridge according to claim 1, wherein the toner cartridge is a toner cartridge having a toner cartridge.

10. an apparatus main body including a photosensitive drum and the developing unit; and the toner cartridge according to any one of claims 1 to 9. An image forming apparatus characterized by:

11. the apparatus main body includes an exposure device that exposes the surface of the photosensitive drum to light to form an electrostatic latent image on the surface; the first discharge opening and the second discharge opening are arranged so as not to overlap the exposure device in the longitudinal direction when the toner cartridge is attached to the developing unit.

11. The image forming apparatus according to claim 10.

12. the apparatus main body includes a rotary that rotatably supports the developing unit; 11. The image forming apparatus according to claim 10.

13. The rotation axis of the rotary extends in the longitudinal direction.

13. The image forming apparatus according to claim 12.

14. A toner cartridge detachably attached to a development unit having a development roller, a frame extending in a longitudinal direction, the frame including a storage chamber for storing toner, and a plurality of discharge ports provided in the frame so as to communicate with the storage chamber, arranged side by side in the longitudinal direction, through which toner passes when discharged from the storage chamber to the developing unit; a partition portion that divides the storage chamber into a plurality of spaces, The plurality of spaces each communicate with at least one of the plurality of exhaust ports. A toner cartridge characterized by:

15. each of the plurality of spaces contains toner, and includes a first space separated by the partition portion and a second space separated from the first space; a first number of the plurality of outlets communicate with the first space; Among the plurality of exhaust ports, a second number of exhaust ports, which is the same as the first number, communicate with the second space.

15. The toner cartridge according to claim 14.

16. an apparatus main body including a photosensitive drum and the developing unit; and the toner cartridge according to claim 14 or 15. An image forming apparatus characterized by:

17. the apparatus main body includes a rotary that rotatably supports the developing unit; 17. The image forming apparatus according to claim 16.

18. The rotation axis of the rotary extends in the longitudinal direction.

18. The image forming apparatus according to claim 17.

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