Patent Description:
Conventionally, there is known a developing cartridge including a storage medium, a holder, a holder cover, a gear cover, and a casing. The developing memory is held by a holder. The holder is held by the holder cover. The holder is movable with respect to the holder cover. The holder cover is fixed to the casing via the gear cover. The gear cover covers the gear. The casing is configured to store developer.

The holder includes a first member, a second member, and an elastic member. The elastic member is disposed between the first member and the second member. The holder is expandable and contractible by an elastic member. In the process of attaching the developing cartridge to the image forming apparatus, the holder is extended by the elastic member, so that the electrical contact surface of the developing cartridge is brought into contact with the main body electrical contact of the image forming apparatus. Document <CIT> discloses a developing cartridge for use in image forming apparatus, which has a holder for holding electrical contact surface and is positioned at end in direction of casing, where holder and contact surface are movable relative to casing.

It is desirable to reduce friction of an electrical contact surface of a developing cartridge against a main body electrical contact of an image forming apparatus by a method different from a conventional technique.

An object of the present disclosure is to provide a technique capable of reducing friction between an electrical contact surface of a developing cartridge and an image forming apparatus.

According to an aspect of the present disclosure, there is provided a developing cartridge including a housing, a developing roller, a storage medium, and a holder. The housing is configured to store developer. The developing roller is rotatable about a first axis extending in a first direction. The developing roller is positioned at one end portion of the housing in a second direction intersecting the first direction. The storage medium has an electrical contact surface. The holder is positioned at one end portion of the housing in the first direction. The holder holds the electrical contact surface. The holder is movable with respect to the housing between a first position and a second position different from the first position in a third direction intersecting the electrical contact surface. The roller is rotatable about a second axis extending in the first direction. The roller includes a first roller protrusion extending in the first direction. The first roller protrusion is contactable with the holder. The first roller protrusion is movable between a third position and a fourth position according to rotation of the roller. The holder is movable along with the movement of the first roller protrusion. When the first roller protrusion moves from the third position to the fourth position, the holder moves from the first position to the second position.

That is, since the holder moves from the first position to the second position by the first roller protrusion of the roller moving from the third position to the fourth position, the movement of the electrical contact surface can be controlled by the rotation of the roller. As a result, friction between the electrical contact surface and the main body electrical contact of the image forming apparatus can be reduced.

For example, when the first roller protrusion moves from the third position to the fourth position, the first roller protrusion lifts the holder from the first position to the second position.

Accordingly, the holder can be lifted by the rotation of the roller.

For example, the developing cartridge further includes a holder cover. For example, the holder cover holds the holder to be movable between the first position and the second position. For example, when the first roller protrusion moves from the third position to the fourth position, the holder moves from the first position to the second position such that the electrical contact surface moves away from the holder cover.

That is, the holder can be held by the holder cover.

For example, the holder cover covers at least a portion of the roller.

That is, the roller can be protected by the holder cover.

For example, the holder includes a holder protrusion extending in the first direction. For example, the holder cover has a groove into which the holder protrusion is inserted. For example, the groove extends in the third direction.

That is, it is possible to restrict the movement direction of the holder by the holder protrusion moving in the groove of the holder cover.

For example, the roller includes a roller main body and rubber. The rubber is located on an outer circumferential surface of the roller body.

That is, it is possible to increase the friction of the outer surface of the roller by the rubber.

For example, the holder has a first end portion and a second end portion. For example, the first end portion holds the electrical contact surface. For example, the second end portion is closer to the developing roller than the electrical contact surface in the third direction. For example, in a state where the first roller protrusion is located at the fourth position, the first roller protrusion is in contact with the second end portion.

For example, the developing cartridge further includes a gear cover. For example, the gear cover is positioned at one end portion of the housing in the first direction. For example, the gear cover holds the roller to be rotatable about the second axis.

That is, the roller can be held by the gear cover.

For example, the gear cover includes a gear cover protrusion extending in the first direction. For example, the gear cover protrusion overlaps with the second axis. For example, the roller has an insertion hole into which the gear cover protrusion is inserted.

For example, the roller is positioned between the gear cover and the holder in the first direction.

For example, the developing cartridge further includes a first protrusion extending in a direction intersecting the first direction. For example, when the first roller protrusion is located at the third position, the first roller protrusion is in contact with the first protrusion. For example, when the first roller protrusion is located at the fourth position, the first roller protrusion is separated from the first protrusion.

That is, since the first roller protrusion is in contact with the first protrusion in a state where the first roller protrusion is located at the third position, it is possible to restrict the first roller protrusion from further moving from the third position.

For example, the roller further includes a second roller protrusion extending in the first direction. For example, when the first roller protrusion is located at the third position, the second roller protrusion is separated from the first protrusion. For example, when the first roller protrusion is located at the fourth position, the second roller protrusion is in contact with the first protrusion.

That is, the second roller protrusion is in contact with the first protrusion in a state where the first roller protrusion is located at the fourth position. As a result, the first roller protrusion moved from the third position to the fourth position can be restricted from further moving.

For example, the first protrusion is positioned between the first roller protrusion and the second roller protrusion in the second direction.

That is, the rotation of the roller can be restricted by the first roller protrusion and the second roller protrusion coming into contact with the first protrusion by the rotation of the roller.

For example, the developing cartridge is attachable to an image forming apparatus. For example, when the developing cartridge is attached to the image forming apparatus, the first roller protrusion rotates from the third position to the fourth position in a state where the outer circumferential surface of the roller is in contact with the image forming apparatus.

Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. Note that components described in these embodiments are merely examples, and the scope of the present disclosure is not intended to be limited only to them. In the drawings, for ease of understanding, the size or the number of each part may be simplified and illustrated as necessary.

<FIG> is a schematic overall view of an image forming apparatus <NUM> according to an embodiment. The image forming apparatus <NUM> is an apparatus that forms an image on a print medium such as a print sheet. The image forming apparatus <NUM> includes an apparatus main body <NUM>. The process unit U1 is attachable to the apparatus main body <NUM>. The process unit U1 includes a developing cartridge <NUM> and a drum cartridge <NUM>. The developing cartridge <NUM> is attachable to the drum cartridge <NUM>.

In the following description, a direction in which a rotation axis (developing roller axis A22) of the developing roller <NUM> included in the developing cartridge <NUM> extends is referred to as a "first direction". A direction in which the developing roller <NUM> and the handle <NUM> are arranged is referred to as a "second direction". A direction intersecting the electrical contact surface <NUM> of the developing cartridge <NUM> will be referred to as a "third direction". The first direction intersects the second direction, and is preferably orthogonal to the second direction. The second direction intersects the third direction, and is preferably orthogonal to the third direction.

The apparatus main body <NUM> includes a box-shaped main body frame <NUM>. The main body frame <NUM> has an opening <NUM>. The opening <NUM> is positioned at an end portion of the main body frame <NUM> in the second direction. The main body frame <NUM> includes a main body cover <NUM>. The main body cover <NUM> is positioned at an end portion of the main body frame <NUM> in the second direction. The main body frame <NUM> includes a hinge <NUM>. The hinge <NUM> is positioned at an end portion of the main body cover <NUM> in the third direction. The main body cover <NUM> is movable about the hinge <NUM> between a closed position for closing the opening <NUM> and an open position for opening the opening <NUM>. The process unit U1 is attachable to the main body frame <NUM> in a state where the opening <NUM> is open.

The main body frame <NUM> includes a guide frame <NUM>. The guide frame <NUM> has a main body electrical contact <NUM>. When the process unit U1 is attached to the image forming apparatus <NUM>, the guide frame <NUM> comes into contact with the holder <NUM> of the developing cartridge <NUM>. The guide frame <NUM> guides the holder <NUM> so that the holder <NUM> moves along a predetermined path. In a state where the process unit U1 is attached to the main body frame <NUM>, the main body electrical contact <NUM> is in contact with the electrical contact surface <NUM> of the developing cartridges <NUM>. Herein, the main body electrical contact <NUM> and the electrical contact surface <NUM> are referred to in singular form, but may also be in plural form, respectively. The main body electrical contact <NUM> is electrically connected to a main body control portion of the image forming apparatus <NUM>. When the main body electrical contact <NUM> is in contact with the electrical contact surface <NUM>, the main body control portion can read information from the developing memory <NUM> and write information to the developing memory <NUM>.

<FIG> is a perspective view of the developing cartridge <NUM> according to the embodiment. <FIG> is an exploded perspective view illustrating one end portion of the developing cartridge <NUM> in the first direction. <FIG> is a perspective view illustrating one end portion of the developing cartridge <NUM> in the first direction. <FIG> is a side view illustrating one end portion of the developing cartridge <NUM> in the first direction. <FIG> is a perspective view illustrating one end portion of the developing cartridge <NUM> in the first direction. <FIG> is a side view illustrating one end portion of the developing cartridge <NUM> in the first direction.

<FIG> and <FIG> illustrate a state in which a holder cover <NUM> included in the developing cartridge <NUM> is removed. <FIG> and <FIG> are cross-sectional views of the holder cover <NUM> taken along a plane perpendicular to the first direction.

As shown in <FIG>, the developing cartridge <NUM> includes a housing <NUM> and a developing roller <NUM>. The housing <NUM> is capable of accommodating the developer. The developer is, for example, toner. The housing <NUM> extends in the first direction. The housing <NUM> has a handle <NUM>. The developing roller <NUM> is positioned at one end portion of the housing <NUM> in the second direction. The handle <NUM> is positioned at the other end portion of the housing <NUM> in the second direction.

The developing roller <NUM> is rotatable about a developing roller axis A22 extending in the first direction in a state where the developing cartridge <NUM> is attached in the image forming apparatus <NUM>. The developing roller axis A22 is an example of a "first axis". In a state where the developing cartridge <NUM> is attached in the image forming apparatus <NUM>, the developing roller <NUM> supplies the developer in the housing <NUM> to the surface of the photosensitive drum <NUM> of the drum cartridge <NUM>.

The developing cartridge <NUM> includes a gear cover <NUM>. The gear cover <NUM> is positioned at one end portion of the housing <NUM> in the first direction. The gear cover <NUM> is attached to one end portion of the housing <NUM> in the first direction. The gear cover <NUM> covers a gear of the developing cartridge <NUM>.

The developing cartridge <NUM> includes a developing memory unit <NUM>. As shown in <FIG>, the developing memory unit <NUM> includes a developing memory <NUM>, a holder <NUM>, and a holder cover <NUM>. The developing memory unit <NUM> is positioned at one end portion of the gear cover <NUM> in the first direction.

The developing memory <NUM> stores various kinds of information related to the developing cartridge <NUM>. The developing memory <NUM> stores, for example, identification information and/or lifetime information. The identification information is information for identifying each developing cartridge <NUM>, and is, for example, a serial number. The life information includes, for example, a cumulative number of rotations obtained by accumulating the number of rotations of the developing roller <NUM>, a cumulative number of printed sheets obtained by accumulating the number of printed sheets using the developing roller <NUM>, and/or a cumulative number of dots obtained by accumulating the number of dots of the developing roller <NUM>. In other words, the cumulative number of rotations is a cumulative value of the number of rotations of the developing roller <NUM> from a brand-new state. The developing memory <NUM> is an example of a "storage medium".

The developing memory <NUM> includes a developing substrate <NUM>, an electrical contact surface <NUM>, and a storage element <NUM>. The developing substrate <NUM> is a plate-like member. The electrical contact surface <NUM> is located at one end portion of the developing substrate <NUM> in the third direction. The electrical contact surface <NUM> is electrically connected to the storage element <NUM>. As shown in <FIG>, in a state where the developing cartridge <NUM> is attached to the main body frame <NUM>, the electrical contact surface <NUM> intersects the third direction. The electrical contact surface <NUM> is movable with respect to the housing <NUM> at least in the third direction.

The holder <NUM> is positioned at one end portion of the housing <NUM> in the first direction. The holder <NUM> is positioned between the developing roller <NUM> and the handle <NUM> in the second direction. The holder <NUM> holds the electrical contact surface <NUM> by holding the developing substrate <NUM> of the developing memory <NUM>. The developing memory <NUM> is positioned at one end portion of the holder <NUM> in the third direction.

The holder <NUM> is movable with respect to the housing <NUM> and the gear cover <NUM> between a first position P1 shown in <FIG> and a second position P2 shown in <FIG>. In the third direction, the second position P2 is different from the first position P1. In the process of attaching the process unit U1 in the image forming apparatus <NUM>, the holder <NUM> is preferably disposed at the first position P1 by the weights of the holder <NUM> and the developing memory <NUM>. In the present embodiment, the first position P1 is a position separated downward from the second position P2.

The holder <NUM> includes a holder protrusion <NUM> extending in the first direction. The holder protrusion <NUM> is positioned at one end portion of the holder <NUM> in the first direction.

The holder cover <NUM> is positioned at one end portion of the gear cover <NUM> in the first direction. The holder cover <NUM> is attached to the gear cover <NUM> by a plurality of screws. The holder cover <NUM> holds the holder <NUM> movably between the first position P1 and the second position P2.

When the first roller protrusion <NUM> moves from the third position P3 to the fourth position P4, the holder <NUM> moves from the first position P1 to the second position P2 such that the electrical contact surface <NUM> moves away from the holder cover <NUM>.

The holder cover <NUM> has a groove <NUM>. The groove <NUM> is a through-hole penetrating the holder cover <NUM> in the first direction. The groove <NUM> extends in the third direction. The length of the holder protrusion <NUM> in the second direction is smaller than the length of the groove <NUM> in the second direction. In the second direction, the holder protrusion <NUM> is inserted into the groove <NUM> in a state where there is a spatial margin. Therefore, the holder protrusion <NUM> is movable in the third direction with respect to the holder cover <NUM>. When the holder <NUM> moves in the third direction with respect to the holder cover <NUM>, the holder protrusion <NUM> moves in the third direction inside the groove <NUM>. By inserting the holder protrusion <NUM> into the groove <NUM>, the direction in which the holder <NUM> can move is restricted.

The developing cartridge <NUM> includes a roller <NUM>. The roller <NUM> is positioned at one end portion of the gear cover <NUM> in the first direction. The roller <NUM> is rotatable with respect to the housing <NUM> and the gear cover <NUM> about a roller axis A40 (second axis) extending in the first direction. The roller <NUM> has a circular cross-section and has a width in the first direction. The roller <NUM> may comprise a hollow cylinder. The roller <NUM> may have a cross-section with a shape different from a circular shape, such as an elliptical shape or a fan shape.

As shown in <FIG>, the roller <NUM> is positioned between the gear cover <NUM> and the holder <NUM> in the first direction. The holder cover <NUM> covers at least a part of the roller <NUM>. Therefore, the holder cover <NUM> protects the roller <NUM>.

The gear cover <NUM> rotatably holds the roller <NUM> with respect to the roller axis A40. More specifically, the gear cover <NUM> has a gear cover protrusion <NUM>. The gear cover protrusion <NUM> is positioned at one end portion of the gear cover <NUM> in the first direction. The gear cover protrusion <NUM> extends in the first direction. As shown in <FIG>, the roller <NUM> has an insertion hole <NUM> penetrating in the first direction. The gear cover protrusion <NUM> is inserted into the insertion hole <NUM>. The roller <NUM> is rotatable about the gear cover protrusion <NUM>. The gear cover protrusion <NUM> overlaps with the roller axis A40 in the first direction. The roller <NUM> rotates about the gear cover protrusion <NUM>.

As shown in <FIG>, the roller <NUM> includes a first roller protrusion <NUM> and a second roller protrusion <NUM>. The first roller protrusion <NUM> and the second roller protrusion <NUM> are positioned at one end portion of the roller <NUM> in the first direction.

The first roller protrusion <NUM> extends in the first direction. The first roller protrusion <NUM> is contactable with the holder <NUM>. As the roller <NUM> rotates, the first roller protrusion <NUM> is movable between a third position P3 shown in <FIG> and a fourth position P4 shown in <FIG>. The holder <NUM> is movable along with the movement of the first roller protrusion <NUM>. When the first roller protrusion <NUM> moves from the third position P3 to the fourth position P4, the holder <NUM> moves from the first position P1 to the second position P2. In the present embodiment, when the first roller protrusion <NUM> moves from the third position P3 to the fourth position P4, the first roller protrusion <NUM> lifts the holder <NUM> from the first position P1 to the second position P2. In other words, the second position P2 is a position separated vertically upward from the first position P1.

As shown in <FIG> and <FIG>, the holder <NUM> has a first end portion <NUM> and a second end portion <NUM>. The first end portion <NUM> holds the electrical contact surface <NUM>. The second end portion <NUM> is located closer to the developing roller <NUM> than the electrical contact surface <NUM> in the third direction. As shown in <FIG>, in a state where the first roller protrusion <NUM> is located at the third position P3, the first roller protrusion <NUM> is separated from the second end portion <NUM>. As shown in <FIG>, in a state where the first roller protrusion <NUM> is located at the fourth position P4, the first roller protrusion <NUM> is in contact with the second end portion <NUM>.

As shown in <FIG> and <FIG>, the holder cover <NUM> has a cover protrusion <NUM>. The cover protrusion <NUM> extends in a direction intersecting the first direction. As shown in <FIG> and <FIG>, the cover protrusion <NUM> extends in the third direction. As shown in <FIG> and <FIG>, the cover protrusion <NUM> is positioned between the first roller protrusion <NUM> and the second roller protrusion <NUM> in the second direction.

As shown in <FIG>, in a state where the first roller protrusion <NUM> is located at the third position P3, the first roller protrusion <NUM> is in contact with the cover protrusion <NUM>. As shown in <FIG>, in a state where the first roller protrusion <NUM> is located at the fourth position P4, the first roller protrusion <NUM> is separated from the cover protrusion <NUM>. The cover protrusion <NUM> is an example of a "first protrusion".

As shown in <FIG>, in a state where the first roller protrusion <NUM> is located at the third position P3, the second roller protrusion <NUM> is separated from the cover protrusion <NUM>. As shown in <FIG>, in a state where the first roller protrusion <NUM> is located at the fourth position P4, the second roller protrusion <NUM> is in contact with the cover protrusion <NUM>. Thus, rotation of the first roller protrusion <NUM> is restricted.

As shown in <FIG>, the roller <NUM> includes a rubber <NUM> and a roller body <NUM>. The rubber <NUM> is positioned on the outer circumferential surface of the roller body <NUM>. The roller body <NUM> is made of, for example, resin. The outer circumferential surface of the roller body <NUM> is recessed in a direction towards the roller axis A40 in the radial direction. The radial direction is a direction orthogonal to the roller axis A40. The rubber <NUM> is fitted into the concave outer circumferential surface of the roller body <NUM>. The rubber <NUM> has, for example, an annular shape. The rubber <NUM> is rotatable together with the roller body <NUM> about the roller axis A40.

<FIG> is a side view showing a process of attaching the process unit U1 in the image forming apparatus <NUM>. In <FIG>, only a part of a main body frame <NUM> of the image forming apparatus <NUM> is illustrated. As shown in <FIG>, the process unit U1 is inserted into the main body frame <NUM> in the second direction.

The main body frame <NUM> has a frame protrusion <NUM>. The frame protrusion <NUM> extends in the second direction. The frame protrusion <NUM> protrudes from the guide frame <NUM> in the third direction. The width of the frame protrusion <NUM> in the first direction is less than the width of the roller <NUM> in the first direction. In the process of inserting the process unit U1 into the main body frame <NUM>, the rubber <NUM> positioned on the outer circumferential surface of the roller <NUM> comes into contact with the frame protrusion <NUM>.

When the process unit U1 is further inserted into the main body frame <NUM> in a state where the rubber <NUM> of the roller <NUM> is in contact with the frame protrusion <NUM>, the roller <NUM> rotates while being in contact with the frame protrusion <NUM>. At this time, a frictional force acts between the roller <NUM> and the frame protrusion <NUM> by the rubber <NUM>. This frictional force causes the roller <NUM> to properly rotate.

When the roller <NUM> starts to rotate in a state where the first roller protrusion <NUM> of the roller <NUM> is at the third position P3 (see <FIG>), the first roller protrusion <NUM> starts to rotate toward the fourth position P4 (see <FIG>). Before the first roller protrusion <NUM> reaches the fourth position P4, the first roller protrusion <NUM> comes into contact with the holder <NUM>. Hereinafter, the position of the first roller protrusion <NUM> when the first roller protrusion <NUM> comes into contact with the holder <NUM> is referred to as a "contact position". In a process in which the first roller protrusion <NUM> rotates from the contact position toward the fourth position P4, the first roller protrusion <NUM> pushes the holder <NUM> toward one side in the third direction. As a result, the holder <NUM> starts to move from the first position P1 toward the second position P2. Further, in a state where the first roller protrusion <NUM> reaches the fourth position P4, the holder <NUM> reaches the second position P2.

When the holder <NUM> is located at the second position P2, the electrical contact surface <NUM> of the developing memory <NUM> held by the holder <NUM> is in contact with the main body electrical contact <NUM> of the image forming apparatus <NUM>. Thus, the developing memory <NUM> and the main body control portion of the image forming apparatus <NUM> are electrically connected to each other. When the holder <NUM> is located at the second position P2, the first roller protrusion <NUM> of the roller <NUM> pushes the holder <NUM> in the third direction, so that the electrical contact surface <NUM> is pressed against the main body electrical contact <NUM>. Thus, the electrical contact surface <NUM> stably comes into contact with the main body electrical contact <NUM>.

According to the developing cartridge <NUM>, when the first roller protrusion <NUM> of the roller <NUM> rotates from the third position P3 to the fourth position P4, the holder <NUM> moves from the first position P1 to the second position P2. This movement of the holder <NUM> causes the electrical contact surface <NUM> of the developing memory <NUM> to move in the third direction. Therefore, the movement of the electrical contact surface <NUM> can be controlled by the rotation of the roller <NUM>.

Further, the electrical contact surface <NUM> moves in the third direction and comes into contact with the main body electrical contact <NUM>. Therefore, friction between the electrical contact surface <NUM> and the main body electrical contact <NUM> can be reduced as compared with the case where the electrical contact surface <NUM> contacts the main body electrical contact <NUM> without moving in the third direction.

While the first roller protrusion <NUM> moves from the third position P3 to the fourth position P4 due to the rotation of the roller <NUM>, the first roller protrusion <NUM> lifts the holder <NUM> from the first position P1 to the second position P2. As a result, the electrical contact surface <NUM> of the developing memory <NUM> can be lifted without incorporating a spring into the holder.

The first roller protrusion <NUM> of the roller <NUM> lifts the holder <NUM> to bring the electrical contact surface <NUM> of the developing memory <NUM> into contact with the main body electrical contact <NUM>. As a result, in the process of attaching the process unit U1 to the image forming apparatus <NUM>, it is possible to reduce the interference of the developing memory <NUM> with the guide frame <NUM> and the like located in front of the main body electrical contact <NUM>, thereby reducing the operation load.

Since the rubber <NUM> is elastically deformed, the friction can be increased. Thus, the roller <NUM> can be rotated. In addition, since the rubber <NUM> is elastically deformed, the force with which the first roller protrusion <NUM> lifts the holder <NUM> can be adjusted to an appropriate magnitude. Thus, the electrical contact surface <NUM> can be brought into contact with the main body electrical contact <NUM> with an appropriate force.

The roller <NUM> is rotatably held by the gear cover protrusion <NUM>. Therefore, when the process unit U1 is attached in the image forming apparatus <NUM>, the first roller protrusion <NUM> of the roller <NUM> comes into contact with the cover protrusion <NUM> due to the weight of the roller <NUM>. Accordingly, when the process unit U1 is attached to the image forming apparatus <NUM>, the first roller protrusion <NUM> can be stably disposed at the predetermined third position P3.

Further, when the process unit U1 is attached to the image forming apparatus <NUM>, the first roller protrusion <NUM> is disposed at the third position P3. Therefore, the movement amount (rotation amount) of the first roller protrusion <NUM> at the time of attachment can be made constant. Therefore, even when the process unit U1 is repeatedly attached and detached, the electrical contact surface <NUM> can be appropriately brought into contact with the main body electrical contact <NUM> every time.

In the process of pulling out the process unit U1 from the image forming apparatus <NUM>, the first roller protrusion <NUM> is lowered by the reverse rotation of the roller <NUM>. As a result, the electrical contact surface <NUM> of the developing memory <NUM> is separated from the main body electrical contact <NUM> by the weight of the developing memory <NUM> and the holder <NUM>.

Preferably, the weight of the first roller protrusion <NUM> is greater than the weight of the second roller protrusion <NUM>. By making the weight of the first roller protrusion <NUM> greater than the weight of the second roller protrusion <NUM>, the second roller protrusion <NUM> can be separated from the cover protrusion <NUM> while the first roller protrusion <NUM> is in contact with the cover protrusion <NUM>. In order to make the weight of the first roller protrusion <NUM> greater than the weight of the second roller protrusion <NUM>, the volume of the first roller protrusion <NUM> may be made larger than the volume of the second roller protrusion <NUM>. In order to make the volume of the first roller protrusion <NUM> larger than the volume of the second roller protrusion <NUM>, as shown in <FIG>, the cross-sectional area of the first roller protrusion <NUM> may be made larger than the cross-sectional area of the second roller protrusion <NUM>. In addition, the length of the first roller protrusion <NUM> may be greater than the length of the second roller protrusion <NUM> in the first direction.

The present disclosure is not limited to the above-described embodiments, and various modifications are possible.

The roller <NUM> may not have the rubber <NUM> on the outer circumferential surface. For example, the roller <NUM> may include a fiber member having a large frictional force instead of the rubber <NUM>. Alternatively, the roller body <NUM> made of resin may be brought into direct contact with the guide frame <NUM>, and the roller <NUM> may be rotated by the frictional force of the roller body <NUM> alone.

The groove <NUM> may not be a through-hole but may be a portion having a concave shape into which the end portion of the holder protrusion <NUM> can be inserted.

It is not essential that the cover protrusion <NUM> is part of the holder cover <NUM>. For example, the cover protrusion <NUM> may be a part of the gear cover <NUM>. Further, the cover protrusion <NUM> may be a member attached to the gear cover protrusion <NUM>.

In the above-described embodiment, the developing memory <NUM> having the electrical contact surface <NUM> is held on the outer surface of the holder <NUM>. However, the electrical contact surface <NUM> may be held on the outer surface of the holder <NUM>, and the storage element <NUM> may be disposed at another position of the developing cartridge <NUM>.

In the embodiment described above, the second position P2 is a position separated from the first position P1 in the vertically upward direction. However, the second position P2 may be a position separated vertically downward from the first position P1. Further, the second position P2 may be the same position as the first position P1 in the vertical direction and may be a position horizontally separated from the first position P1. Further, the second position P2 may be a position horizontally and vertically separated from the first position P1.

Claim 1:
A developing cartridge (<NUM>) comprising :
a housing (<NUM>) configured to accommodate a developer;
a developing roller (<NUM>) rotatable about a first axis (A22) extending in a first direction, the developing roller (<NUM>) being positioned at one end portion of the housing (<NUM>) in a second direction intersecting the first direction;
a storage medium (<NUM>) having an electrical contact surface (<NUM>);
a holder (<NUM>) positioned at one end portion of the housing (<NUM>) in the first direction, the holder (<NUM>) holding the electrical contact surface (<NUM>), the holder (<NUM>) being movable relative to the housing (<NUM>) between a first position and a second position different from the first position in a third direction intersecting the electrical contact surface (<NUM>); and characterised in that the developing cartridge further comprises
a roller (<NUM>) rotatable about a second axis (A40) extending in the first direction, the roller (<NUM>) including a first roller protrusion (<NUM>) extending in the first direction, the first roller protrusion (<NUM>) being contactable with the holder (<NUM>); wherein
the first roller protrusion (<NUM>) is movable between a third position and a fourth position in accordance with rotation of the roller (<NUM>),
the holder (<NUM>) is movable in accordance with movement of the first roller protrusion (<NUM>), and
when the first roller protrusion (<NUM>) moves from the third position to the fourth position, the holder (<NUM>) moves from the first position to the second position.