EP2853955A1

EP2853955A1 - Developing device, blade unit, and developing device manufacturing method

Info

Publication number: EP2853955A1
Application number: EP14186531.1A
Authority: EP
Inventors: Hikaru Yoshizumi; Junichi Yokoi
Original assignee: Brother Industries Ltd
Current assignee: Brother Industries Ltd
Priority date: 2013-09-30
Filing date: 2014-09-26
Publication date: 2015-04-01
Also published as: CN104516243A; JP2015069169A

Abstract

A developing device includes a developer carrier, a blade disposed adjacent to the developer carrier, and a supporter supporting the blade. The blade includes a plurality of weld marks joined to the supporter. The plurality of weld marks overlap each other to form a large weld mark.

Description

TECHNICAL FIELD

Aspects disclosed herein relate to a blade unit in which a blade is joined to a supporting member by welding, a developing device using the blade unit, and a manufacturing method of the developing device.

BACKGROUND

Conventionally, there has been an electrophotographic image forming apparatus that includes a developing device including a developing roller and a blade unit for regulating a thickness of a developer layer held on the developing roller. Further, there has been known a blade unit that includes a blade that contacts the developing roller and a supporting member that holds the blade in an overlapping manner.
In the blade unit, the blade and the supporting member are welded to each other at a plurality of locations in a longitudinal direction of the blade. Therefore, the blade is formed with a plurality of weld marks spaced apart from each other.

SUMMARY

Nevertheless, each weld mark formed using the above-described technique might not have a fixing strength that is strong enough, and therefore, the blade might not be fixed to the supporting member securely.
Accordingly, for example, some embodiments of the disclosure provide for a developing device, a blade unit, and a developing device manufacturing method in which a blade may be fixed to a supporting member securely.
According to one or more aspects of the disclosure, a developing device may include a developer carrier, a blade disposed adjacent to the developer carrier, and a supporter supporting the blade. The blade may include a plurality of weld marks joined to the supporter. The plurality of weld marks may overlap each other to form a large weld mark.
According to one or more other aspects of the disclosure, a blade unit may include a blade and a supporter supporting the blade. The blade may include a plurality of weld marks joined to the supporter. The plurality of weld marks may overlap each other to form a large weld mark.
According to one or more other aspects of the disclosure, a manufacturing method for developing device, which may include a developer carrier, a blade disposed adjacent to the developer carrier, and a supporter supporting the blade, may include placing the blade on the supporter and welding the blade to the supporter such that adjacent weld marks overlap each other.
According to the aspects of the disclosure, the blade may be fixed to the supporting member more securely as compared with a case where the weld marks do not overlap one another.

DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present disclosure, needs satisfied thereby, and the objects, features, and advantages thereof, reference now is made to the following descriptions taken in connection with the accompanying drawings.

Fig. 1 is a disassembled perspective view depicting a developing device in an illustrative embodiment according to one or more aspects of the disclosure.
Fig. 2 is a sectional view depicting the developing device in the illustrative embodiment according to one or more aspects of the disclosure.
Figs. 3A illustrates a blade unit in the illustrative embodiment according to one or more aspects of the disclosure.
Fig. 3B is an enlarged view of a portion A of Fig. 3A in the illustrative embodiment according to one or more aspects of the disclosure.
Fig. 4A is a diagram for explaining a preparation process in a developing device manufacturing method in the illustrative embodiment according to one or more aspects of the disclosure.
Fig. 4B is a diagram for explaining a welding process in the developing device manufacturing method in the illustrative embodiment according to one or more aspects of the disclosure.
Fig. 5 illustrates a laser microscope image of a weld mark formed on a blade in the welding process in the illustrative embodiment according to one or more aspects of the disclosure.
Fig. 6A illustrates a blade unit in a first variation of the illustrative embodiment according to one or more aspects of the disclosure.
Fig. 6B is an enlarged view of weld marks in the first variation of the illustrative embodiment according to one or more aspects of the disclosure.
Fig. 6C is an enlarged view of weld marks in a second variation of the illustrative embodiment according to one or more aspects of the disclosure.
Fig. 7 illustrates a laser microscope image of a weld mark formed on the blade in the welding process in the first variation of the illustrative embodiment according to one or more aspects of the disclosure.
Fig. 8A illustrates a blade unit in a third variation of the illustrative embodiment according to one or more aspects of the disclosure.
Fig. 8B is an enlarged view of weld marks in the third variation of the illustrative embodiment according to one or more aspects of the disclosure.
Fig. 9 is a diagram for explaining a blade unit assembling method in the third variation of the illustrative embodiment according to one or more aspects of the disclosure.
Fig. 10A is an enlarged view of weld marks in a fourth variation of the illustrative embodiment according to one or more aspects of the disclosure.
Fig. 10B is an enlarged view of weld marks in a fifth variation of the illustrative embodiment according to one or more aspects of the disclosure.
Fig. 11 is an enlarged view of weld marks in a sixth variation of the illustrative embodiment according to one or more aspects of the disclosure.
Fig. 12 is an enlarged view of weld marks in a seventh variation of the illustrative embodiment according to one or more aspects of the disclosure.
Fig. 13 is a perspective view depicting a blade unit in an eighth variation of the illustrative embodiment according to one or more aspects of the disclosure.
Fig. 14 is a sectional view depicting a developing device in a ninth variation of the illustrative embodiment according to one or more aspects of the disclosure.

DETAILED DESCRIPTION

Next, an illustrative embodiment of the disclosure is described in detail with referent to the accompanying drawings.
As depicted in Fig. 1, a developing device 1 may comprise mainly a developing roller 2 as an example of a developer carrier, a supply roller 3, a blade unit 4, and a developing case 5 that may hold these components.
The developing case 5 may be a container having therein a toner storage chamber 53 capable of storing toner therein, and may have an opening 51 defined in its one surface. The developing case 5 may define an edge of the opening 51 and comprise a blade support surface 52 to which the blade unit 4 may be fixed.
As depicted in Fig. 2, a conveyor member 7 for conveying toner toward the supply roller 3 may be disposed in the toner storage chamber 53. The conveyor member 7 may comprise a shaft portion 71 that may be rotatably supported by the developing case 5, and a film 72 that may rotate on the shaft portion 71 by rotation of the shaft portion 71.
As depicted in Fig. 1, the developing roller 2 may comprise a cylindrical roller body 2A and a shaft 2B that may be inserted into the roller body 2A and may be rotatable integrally with the roller body 2A. The roller body 2A may have elasticity and may be capable of holding toner on its circumferential surface. The developing roller 2 may be disposed to close the opening 51 of the developing case 5. The shaft 2B that may protrude from the roller body 2A in an axial direction of the developing roller 2 may be rotatably supported by the developing case 5.
The supply roller 3 may be disposed inside the developing case 5 with contacting the developing roller 2, and may be rotatably supported by the developing case 5. The supply roller 3 may be configured to supply toner stored in the developing case 5 to the developing roller 2 by its rotation.
The blade unit 4 may comprise a blade 41 and a supporting member 42 as an example of a supporter. The blade 41 may be disposed near the developing roller 2 such that a tip of the blade 41 may be placed on the developing roller 2. The supporting member 42 may hold the blade 41.
The blade 41 may comprise a sheet metal having a rectangular shape elongated in a direction that an axis of the developing roller 2 may extend. That is, a longitudinal direction of the blade 41 is parallel to the axial direction of the developing roller 2, and a direction perpendicular to the longitudinal direction of the blade 41 may be perpendicular to the axial direction of the developing roller 2. The blade 41 may be made of metallic material, for example, stainless steel. In other embodiments, for example, the blade 41 may comprise a sheet metal whose surface may have coating including press oil.
For example, the blade 41 may have a thickness of 0.05 to 2.5 mm, a thickness of 0.05 to 0.12 mm, a thickness of 0.05 to 1.00 mm, a thickness of 0.07 to 0.15 mm, or a thickness of 0.08 to 0.12 mm. A dimension of the blade 41 in the longitudinal direction may be greater than a dimension of the roller body 2A of the developing roller 2 in the axial direction, and for example, the blade may have a length of 218 to 270 mm, a length of 220 to 260 mm, or a length of 222 to 250 mm.
The blade 41 may comprise a contact portion 411, which may protrude toward the developing roller 2 and directly contact the roller body 2A of the developing roller 2, on a distal end 41E of its surface 41F, facing the developing roller 2, of the blade 41 (see Fig. 2). The contact portion 411 may be made of, for example, rubber and may extend along the longitudinal direction of the blade 41.
The supporting member 42 may be a member for defining a fixing end of the blade 41 as well as holding the blade 41.
The supporting member 42 may be made of metallic material, for example, electrolytic zinc-coated carbon steel sheet. The supporting member 42 may have a thickness greater than the blade 41 and a substantially rectangular shape elongated in the longitudinal direction of the blade 41. The supporting member 42 may extend so as to exceed both ends 413 of the blade 41 in the longitudinal direction of the blade 41.
The supporting member 42 may overlap the other surface of the blade 41 and pinch the blade 41 in conjunction with the blade support surface 52 of the developing case 5 such that the blade 41 is interposed therebetween. The other surface of the blade 41 may be opposite to the surface 41F on which the contact portion 411 of the blade 41 may be disposed. More specifically, the blade 41 may be pinched between an edge 42E of the supporting member 42 and an edge 52E of the support surface 52, wherein the edge 42E of the supporting member 42 and the edge 52E of the support surface 52 may be located on the distal end 41E side of the blade 41. A portion, which may contact the edge 42E of the supporting member 42 and the edge 52E of the blade support surface 52, of the blade 41 may function as a fulcrum when the blade 41 bends.
The blade unit 4 configured as described above may be fixed to the developing case 5 using screws 6 through holes H in the blade 41 and the supporting member 42. In this state, the blade unit 4 may be configured to regulate a thickness of a toner layer held on the developing roller 2 by the contact portion 411 that may contact the rotating developing roller 2.
As depicted in Fig. 3A, the supporting member 42 may comprise a positioning protrusion 421, which may be engaged with the blade 41, at each end portion in the longitudinal direction on its surface that may face the blade 41. The blade 41 may have a pair of openings 412 that may be engaged with the pair of positioning protrusions 421. One of the pair of openings 412 may be a circular opening and the other of the pair of openings 412 may be an elongated opening. The elongated opening of the pair of openings 412 may absorb a dimensional deviation between the two openings 412 and linear expansion of the blade 41 and the supporting member 42 in the longitudinal direction. The blade 41 may be positioned with respect to the supporting member 42 by the engagement of the openings 412 and the corresponding positioning protrusions 421, respectively.
The blade 41 may be welded to the supporting member 42 at a plurality of locations in the longitudinal direction. More specifically, the blade 41 may be joined to the supporting member 42 by laser welding at each portion of the blade 41 outward than each positioning protrusion 421 in the longitudinal direction and a portion of the blade 41 between the positioning protrusions 421 in the longitudinal direction.
The blade 41 may have a first large weld mark 43, as an example of a large weld mark, which may join the blade 41 and the supporting member 42 at a position between the positioning protrusions 421, and second large weld marks 44, as another example of the large weld mark, which may join the blade 41 and the supporting member 42 at respective positions more outward than the respective positioning protrusions 421 in the longitudinal direction.
The first large weld mark 43 may continue from a vicinity of the one of the openings 412 to a vicinity of the other of the openings 412 along the longitudinal direction of the blade 41.
As depicted in Fig. 3B, the first large weld mark 43 may include a plurality of weld marks 43 A that may be aligned along the longitudinal direction of the blade 41, wherein adjacent ones of the plurality weld marks 43 A may overlap each other. That is, the plurality of weld marks 43 A that the blade 41 may have may partially overlap one another, thereby constituting the large weld mark 43. A weld mark may refer to a weld that may be formed by one laser irradiation.
Each weld mark 43A may have a circular shape. The circular shape according to the illustrative embodiment may include a circular shape in which a dimension of a most elongated portion (e.g., longest diameter) may be within a range of 110 to 330% of a dimension of a least elongated portion (e.g. shortest diameter). In other embodiments, for example, the dimension of the most elongated portion (e.g., longest diameter) may be within a range of 110 to 250%, a range of 100 to 120%, a range of 100 to 110%, a range of 101 to 105%, or a range of 101 to 115% of the dimension of the least elongated portion (e.g. shortest diameter). For example, one of the weld marks 43 A may have a size of 0.1 to 6.0 mm. In other embodiments, the one of the weld marks 43 A may have a size of 0.3 to 4.0 mm or a size of 0.5 to 2.0 mm.
The plurality of weld marks 43 A may overlap on top of one another in an order in which the plurality of weld marks 34A may be arranged in the longitudinal direction of the blade 41 from the circular opening 412 side. Adjacent ones of the plurality of weld marks 43 A may partially overlap each other. In one weld mark 43, an area of overlapping regions (e.g., hatched regions) where the one weld mark 43 A may overlap other weld marks 43 A may be smaller than an area of a non-overlapping region where the one weld mark 43 A might not overlap the other weld marks 43 A.
In the plurality of weld marks 43A overlapping one another as described above, an interval X between weld marks 43 A formed on both sides of one weld mark 43 A may be greater than a width Y of an overlapping region of the one weld mark 43 A and one of the adjacent weld marks 34A.
In the first large weld mark 43 including the plurality of weld marks 43 A, a dimension of the first large weld mark 43 in the longitudinal direction of the blade 41 may be greater than a dimension of the first large weld mark 43 in the direction perpendicular to the longitudinal direction of the blade 41. The first large weld mark 43 may have necking portions 431 at a plurality of locations in the longitudinal direction of the blade 41. For example, the first large weld mark 43 may have a dimension of 0.1 to 250 mm in a direction that the plurality of weld marks 43 A may be arranged, that is, in the longitudinal direction, and a dimension of 0.1 to 6.0 mm in the direction perpendicular to the longitudinal direction of the blade 41. In other embodiments, for example, the first large weld mark 43 may have a dimension of 0.3 to 4.0 mm or a dimension of 0.5 to 2.0 mm in the direction perpendicular to the longitudinal direction of the blade 41.
As depicted in Fig. 3A, the second large weld marks 44 may continue from respective vicinities of the openings 412 to respective vicinities of the ends 413 of the blade 41 along the longitudinal direction of the blade 41.
In a similar manner to the first large weld mark 43 depicted in Fig. 3B, each second large weld mark 44 may include a plurality of circular weld marks 43 A that may be arranged along the longitudinal direction of the blade 41 with overlapping one another (not depicted).
Hereinafter, advantages of the blade unit 4 configured as described above is described.
The first large weld mark 43 and the second large weld marks 44 formed on the blade 41 each may consist of the plurality of weld marks 43A overlapping one another. Therefore, the blade 41 may be fixed to the supporting member 42 more securely as compared with a configuration in which weld marks might not overlap one another.
The plurality of weld marks 43A may be arranged along the longitudinal direction of the blade 41, and each of the first large weld mark 43 and the second large weld marks 44 may continue along the longitudinal direction of the blade 41. Therefore, this configuration may reduce a risk of applying a strong force to a particular portion of the blade 41 when the blade 41 is made contact with the developing roller 2.
Next, a manufacturing method of the developing device 1 is described.
When the blade unit 4 is assembled for manufacturing the developing device 1, first, as depicted in Fig. 4A, the blade 41 may be placed on the supporting member 42 (e.g., a preparation process). At that time, the openings 412 in the blade 41 may be engaged with the corresponding positioning protrusions 421, respectively, of the supporting member 42.
Then, the blade 41 and the supporting member 42 may be fastened on a worktable. Thereafter, as depicted in Fig. 4B, while a laser beam 81 irradiated from the welding machine 8 is moved with respect to the blade 41, the laser beam 81 may be irradiated on the blade 41 to weld the blade 41 and the supporting member 42 to each other (e.g., a welding process).
In the illustrative embodiment, the welding machine 8 may be configured to irradiate a portion, which may face the welding machine 8, of an object with a pulsed laser as the laser beam 81. In other embodiments, for example, another welding machine that may be configured to irradiate the blade 41 with a laser beam by moving a reflector provided inside the welding machine, without moving the welding machine itself, may be used. For example, an yttrium aluminum garnet ("YAG") laser or a fiber laser may be adopted as the pulsed laser.
In the welding process, the laser beam 81 may be moved with respect to the blade 41 along the longitudinal direction of the blade 41 from one end portion, in which the circular opening 412 may be defined, to the other end portion, in which the elongated opening 412 may be defined, of the blade 41. At that time, the laser beam 81 may be irradiated to each portion that may be apart from each end of the blade 41 and the edges of the openings 412.
Welding starting from the circular opening 412 side as described above may allow the elongated opening 412 to absorb a thermal expansion of the blade 41 that may occur during welding.
The laser beam 81 may be moved with respect to the blade 41 at a speed which may allow to form adjacent weld marks 43A may overlap each other, and more specifically, an area of overlapping regions where one weld mark 43A may overlap other weld marks 43 A may be smaller than an area of a non-overlapping region where the one weld mark 43 A might not overlap the other weld marks 43 A.
As an example, Fig. 5 illustrates a weld mark formed by the welding process using a blade made of stainless steel (e.g., a thickness of 0.1 mm) as the blade 41, a supporting member made of electrolytic zinc-coated carbon steel sheet (e.g., a thickness of 1.2 mm) as the supporting member 42, and a fiber laser welding machine ML-6700A (manufactured by MIYACHI CORPORATION) as the welding machine. In the welding process, a pulsed laser was used as a laser beam, and the laser beam was moved at a speed of 200 mm/sec with respect to the blade, where a spot diameter of the laser beam was 0.2 mm, a pulse width of the laser beam was 1.0 msec, and power of the laser beam was 400 W. The weld mark was observed by the VK-X200 series laser microscope (manufactured by KEYENCE CORPORATION).
While the disclosure has been described in detail with reference to the specific embodiment thereof, it is not limited to the specific embodiment. Various changes, arrangements and modifications may be applied to the detailed configuration without departing from the spirit and scope of the disclosure. In the description below, common parts have the same reference numerals as those of the above-described embodiment, and the detailed description of the common parts is omitted.
In the illustrative embodiment, the blade 41 and the supporting member 42 may be joined to each other by welding using a pulsed laser, such as a YAG laser, and the circular weld marks 43 A may be formed on the blade 41. Nevertheless, the welding method of the blade 41 and the supporting member 42 might not be limited to the specific embodiment. In other embodiments, for example, as depicted in Figs. 6A and 6B, the blade 41 and the supporting member 42 may be joined to each other by welding using, for example, a continuous wave laser such as a fiber laser, and weld marks 45A each having a greater dimension in the longitudinal direction of the blade 41 than a dimension in the direction perpendicular to the longitudinal direction of the blade 41 may be formed on the blade 41.
More specifically, the blade 41 may be formed with a large weld mark 45 constituted of a plurality of weld marks 45A that may be disposed at a plurality of locations and arranged along the longitudinal direction with partially overlapping one another. One weld mark 45A may overlap an adjacent weld mark 45A each other, and the large weld mark 45 may have a plurality of necking portions 451 at a plurality of locations in the longitudinal direction of the blade 41.
An interval X between weld marks 45A formed on both sides of one weld mark 45 A may be greater than a width Y of an overlapping region of the one weld mark 45A and one of the adjacent weld marks 45A. In one weld mark 45A, an area of overlapping regions (e.g., hatched regions) where the one weld mark 45A may overlap other weld marks 45 A may be smaller than an area of a non-overlapping region where the one weld mark 45 A might not overlap the other weld marks 45A.
As an example, Fig. 7 illustrates a weld mark formed on a blade as a result of welding in which a laser beam such as a pulsed laser was moved at a speed of 200 mm/sec with respect to the blade, where a spot diameter of the laser beam was 0.1 mm, a pulse width of the laser beam was 0.35 msec, and power of the laser beam was 400 W. The welding machine, the blade, and the supporting member used to form the weld mark depicted in Fig. 7 may be the same as those used to form the weld mark depicted in Fig. 5.
As depicted in Fig. 6C, the large weld mark 45 may include a plurality of weld marks 45B that may overlap one another such that an area of overlapping regions (e.g., hatched regions) where one weld mark 45B may overlap other weld marks 45B may larger than an area of a non-overlapping region where the one weld mark 45B might not overlap the other weld marks 45B. In this case, an interval X of weld marks 45B formed on both sides of the one weld mark 45B may be narrower than a width Y of the overlapping region of the one weld mark 45B and one of the adjacent weld marks 45B.
To form such a large weld mark 45, in the welding process, during intervals between irradiations of the laser beam 81, the laser beam 81 may be moved upstream in a moving direction with respect to the blade 71.
In the illustrative embodiment, the plurality of weld marks 43A constituting each of the first large weld mark 43 and the second large weld marks 44 (e.g., large weld marks) may be arranged along the longitudinal direction of the blade 41. Nevertheless, the direction that the plurality of weld marks may be arranged might not be limited to the specific embodiment. In other embodiments, for example, as depicted in Figs. 8A and 8B, a plurality of weld marks 46A constituting each large weld mark 46 may be arranged along the direction perpendicular to the longitudinal direction of the blade 41.
In this case, each large weld mark 46 may have a shape in which its dimension in the direction perpendicular to the longitudinal direction of the blade 41 is longer than its dimension in the longitudinal direction of the blade 41.
The large weld marks 46 may be formed at a plurality of locations, respectively, in the longitudinal direction of the blade 41. It may be preferable that ends, which may be located closer to the contact portion 411, of the plurality of large weld marks 46 are arranged in a straight line extending parallel to a direction that the contact portion 411 may extend such that force is exerted uniformly on the contact portion of the contact portion 411 and the developing roller 2.
To form such a large weld mark 46, in the welding process, as depicted in Fig. 9, a process of moving the laser beam 81 along the direction perpendicular to the longitudinal direction of the blade 41 with respect to the blade 41 and a process of moving the laser beam 81 along the longitudinal direction of the blade 41 with respect to the blade 41 may be alternately repeated.
In other embodiments, for example, a process of moving the laser beam 81 along the direction perpendicular to the longitudinal direction of the blade 41 with respect to the blade 41 and a process of moving the laser beam 81 along the longitudinal direction of the blade 41 with respect to the blade 41 may be repeatedly performed simultaneously.
In this case, as depicted in Fig. 10A, a plurality of weld marks 47A may be arranged along a direction intersecting the longitudinal direction of the blade 41 and thus a large weld mark 47 may extend along a direction intersecting along the longitudinal direction of the blade 41. For another example, as depicted in Fig. 10B, a plurality of weld marks 48A may arranged along two directions each of which may intersect the longitudinal direction of the blade 41 and thus a large weld mark 48 may have a zigzag shape.
For example, as depicted in Fig. 11, the above-described large weld mark 46 may include a plurality of weld marks 46B whose dimension in the direction perpendicular to the longitudinal direction of the blade 41 may be longer than whose dimension in the longitudinal direction of the blade 41. The plurality of weld marks 46B may be arranged along the direction perpendicular to the longitudinal direction of the blade 41.
In the illustrative embodiment, the circular weld marks 43A may be arranged along the longitudinal direction of the blade 41 to constitute the first large weld mark 43 (e.g., the large weld mark). Nevertheless, in other embodiments, for example, as depicted in Fig. 12, a large weld mark 49 may include a plurality of weld marks 49A that may be arranged along the longitudinal direction of the blade 31 and whose dimension in the direction perpendicular to the longitudinal direction of the blade 41 may be longer than whose dimension in the longitudinal direction of the blade 41.
In the illustrative embodiment, the plurality of weld marks 43 A may overlap on top of one another in an order in which the plurality of weld marks 34A may be arranged in the longitudinal direction of the blade 41 from the circular opening 412 side. Nevertheless, the overlapping manner of the weld marks 43 A might not be limited to the specific embodiment. For example, two weld marks may be formed at respective positions distant from each other, and then, another weld mark may be formed between the two distant weld marks so as to overlap each of the distant weld marks, whereby adjacent ones of all the weld marks may overlap each other.
In the illustrative embodiment, the large weld marks (e.g., the first large weld mark 43 and the second large weld marks 44) may be formed at one location in the direction perpendicular to the longitudinal direction of the blade 41. Nevertheless, the number of locations where the large weld marks may be formed might not be limited to the specific embodiment. In other embodiments, for example, two or more large weld marks may be formed at respective positions in the direction perpendicular to the longitudinal direction of the blade 41 so as to be arranged along the direction perpendicular to the longitudinal direction of the blade 41.
In the illustrative embodiment, each of the large weld marks (e.g., the first large weld mark 43 and the second large weld marks 44) may consist of the plurality of weld marks 43 A. Nevertheless, the configuration of the large weld marks formed on the blade 41 might not be limited to the specific embodiment. In other embodiments, for example, the second large weld mark 44 may consist of a single weld mark elongated along the longitudinal direction of the blade 41. That is, there may be, on the blade 41, one large weld mark consisting of the plurality of weld marks 43 A.
In the illustrative embodiment, the blade 41 may be welded to the supporting member 42 at the plurality of locations. Nevertheless, the method of welding the blade 41 might not be limited to the specific embodiment. In other embodiments, for example, the blade 41 may have the first large weld mark 43 and be joined to the supporting member 42 by welding at one location.
In the illustrative embodiment, in the welding process, the laser beam 81 may be moved with respect to the blade 41. Nevertheless, the manner of moving the laser beam 81 with respect to the blade 41 might not be limited to the specific embodiment. In other embodiments, for example, the blade 41 and the supporting member 42 may be moved with respect to the laser beam 81 to move the laser beam 81 with respect to the blade 41 (or the blade 41 may be moved with respect to the laser beam 81).
In still other embodiments, the laser beam 81 and the set of the blade 41 and the supporting member 42 may be moved at the same time.
In the illustrative embodiment, the blade 41 may comprise the contact portion 411 protruding from the blade 41. Nevertheless, the configuration of the blade 41 might not be limited to the specific embodiment. In other embodiments, for example, as depicted in Fig. 13, the blade 41A might not comprise a contact portion made of, for example, rubber, but may comprise a bent portion 411A in which the distal end portion of the blade 41A may be bent toward the supporting member 42 (e.g., toward a side opposite to the developing roller 2). The bent portion 411A (e.g., the distal end of the blade 41) may directly contact the roller body 2A of the developing roller 2.
In the illustrative embodiment, the distal end portion of the blade 41 may be placed on the developing roller 2, and the blade 41 may be pinched by the supporting member 42 and the developing case 5. Nevertheless, the configuration of the blade unit 4 might not be limited to the specific embodiment. In other embodiments, for example, as depicted in Fig. 14, the supporting member 42 to which the blade 41 may be welded may be fixed to the developing case 5 directly while the supporting member 42 is pinched by the blade 41 and the developing case 5. In the blade unit 4, the distal end portion of the blade 41 (e.g., the contact portion 411) may contact the developing roller 2 from the conveyor member 7 side, and the surface, which may be opposite to the surface 41F having the contact portion 411 thereon, of the blade 41 may be supported by the supporting member 42.
In the illustrative embodiment, the developing roller 2 comprising the roller body 2A and the shaft 2B may be illustrated as the developer carrier. Nevertheless, in other embodiments, for example, the developer carrier might not be limited to the specific embodiment. In other embodiments, for example, a brush roller, a developing sleeve, or a belt-shaped developer carrier may be adopted as the developer carrier.
In the illustrative embodiment, the contact portion 411 (e.g., the distal end) of the blade 41 may be in directly contact with the roller body 2A of the developing roller 2 (as an example of the developer carrier). Nevertheless, the configuration of the blade might not be limited to the specific embodiment. In other embodiments, for example, the blade may be disposed such that its distal end portion may be substantially 0.1-1.0 mm apart from the roller body 2A.
In the illustrative embodiment, the stainless steel may be adopted as the metallic material for constituting the blade 41. Nevertheless, the material of the blade 41 might not be limited to the specific embodiment. For example, the blade 41 may be made of, for example, steel for springs, phosphor bronze, beryllium copper, or carbon tool steel. In a case where the steel for springs or the carbon tool steel is adopted, a nickel, chromium, or zinc coating may be applied to the blade 41 for rustproof.
In the illustrative embodiment, the electrolytic zinc-coated carbon steel sheet may be adopted as the metallic material for constituting the supporting member 42. Nevertheless, the configuration of the supporting member 42 might not be limited to the specific embodiment. In other embodiments, for example, the supporting member 42 may be made of a cold rolled steel plate or a tinplate, or a plate made of one of the cold rolled steel plate and the tinplate whose surface may be applied with treatment such as Parkerizing, chromating, or nickel coating. The supporting member 42 may also have a coating including press oil thereon.

Claims

A blade unit comprising:
a blade (41); and

a supporter (42) supporting the blade,

wherein the blade includes a plurality of weld marks (43, 44) joined to the supporter, and the plurality of weld marks overlap each other to form a large weld mark.
The blade unit according to claim 1, wherein the weld mark has a circular shape.
The blade unit according to claim 1, wherein a dimension of the weld mark in a longitudinal direction of the blade is greater than a dimension of the weld mark in a direction perpendicular to the longitudinal direction of the blade.
The blade unit according to any one of claims 1 to 3, wherein the plurality of weld marks are aligned along a longitudinal direction of the blade.
The blade unit according to any one of claims 1 to 4, wherein
the supporter is made of metallic material,
and the blade is made of metallic material.
A developing device comprising:
the blade unit according to anyone of claims 1 to 5; and

a developer carrier (2),

wherein the blade (41) is disposed adjacent to the

developer carrier.
A manufacturing method for developing device comprising a developer carrier (2), a blade (41) disposed adjacent to the developer carrier, and a supporter (42) supporting the blade, the method comprising:
placing the blade on the supporter; and

welding the blade to the supporter such that adjacent weld marks overlap each other.
The manufacturing method according to claim 7, wherein the welding comprises irradiating continuous wave laser and forming the weld mark such that a dimension of the weld mark in a longitudinal direction of the blade is greater than a dimension of the weld mark in a direction perpendicular to the longitudinal direction of the blade.
The manufacturing method according to claim 7 or 8, wherein the welding comprises irradiating a laser beam to the blade and moving at least one of the laser beam and the blade with respect to the other of the laser beam and the blade in a longitudinal direction of the blade.
The manufacturing method according to claim 7 or 8, wherein, in the welding process, while irradiating a laser beam to the blade, a process of moving at least one of the laser beam and the blade with respect to the other of the laser beam and the blade in a direction perpendicular to the longitudinal direction of the blade and a process of moving at least one of the laser beam and the blade with respect to the other of the laser beam and the blade in a longitudinal direction of the blade are alternately repeated or repeatedly performed simultaneously.