JP2767786B2 - Developing device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a small and lightweight developing device suitable for an electrophotographic copying machine or an electrostatic recording device. 2. Description of the Related Art Conventionally, as an example of such a developing device, a two-component developer stored at the bottom is supplied to a developing sleeve arranged at a higher position by a pumping roller, and excess developer after development is supplied. There is known a method in which the toner is moved and transported in the longitudinal direction by the action of a screw or a deflector plate together with the toner, then stirred by the pumping roller, and magnetized and supplied onto the developing sleeve. [0003] However, in this method, a large drawing roller is disposed, so that there is a problem in that the developing device becomes large in both space and weight. In addition, there are also structural problems such as the developer being stored with one-sided offset, or a complicated adjustment required to prevent the developer from being stored. In addition, toner is
In a developing device that directly replenishes the developer carried on the
The developer in the axial direction of the sleeve when supplying toner.
There is also a problem that a variation in toner density occurs. Accordingly, the present invention provides a sleeve which is small in size and light in weight and can be used for storing and supplying toner from a piece of developer without adjustment .
An object of the present invention is to provide a developing device capable of circulating and stirring in a longitudinal direction of a developing sleeve without causing a variation in toner concentration in a developer in an axial direction . [0005] In order to achieve the above object, the present invention provides a developing sleeve which rotates while applying a developer comprising a carrier and a toner, and a developing device carried on the developing sleeve. a toner replenishing means for replenishing the toner directly to agent, and regulating means for regulating the developer on the developing sleeve, in the rotation direction of the developing sleeve, provided between said toner supply means of the regulating means, developing In the drug
A first moving means for moving the developer around the developing sleeve in a first direction of the axial direction of the developing sleeve for uniforming the toner concentration, and moved in the first direction. A second moving unit for moving the developer in a second direction opposite to the first direction. An embodiment shown in the drawings will be described in detail below.
In FIG. 1, reference numeral 1 denotes an electrostatic latent image carrier, which is called a photoreceptor if it is incorporated in an electrophotographic copying machine. A developing device 2 is disposed near the photoconductor 1, and the developing device 2 has therein a toner tank 3, a supply roller 4, a developing sleeve 5, a transport path 10, a first moving unit 6, and a second moving unit. Means 7 and the like. The screw 62 of the developing sleeve 5 and the first moving means 6, which will be described later, is directly driven by a motor M, while the replenishing roller 4 is driven via a clutch C.
Reference numeral K denotes a control unit, which reads the density of the dedicated pattern on the photoreceptor 1 by the photo sensor P, and turns on the clutch C via the control unit K by the toner supply signal. That is, the toner tank 3 stores the toner for replenishment formed in the upper part of the developing device 2, and the replenishment roller 4 is rotated by the toner replenishment signal to drop an appropriate amount of toner downward. On the other hand, the magnetic brush formed on the developing sleeve 5 is formed above the outer periphery of the developing sleeve 5 and is moved in one direction in the axial direction of the developing sleeve by the first moving means 6 provided in the transport path 10. For example, a part of the developer is moved and stirred from the near side to the far side in the drawing. Transport path 1
The remaining developer not captured by the first transfer means 6 is captured by the second moving means 7 disposed downstream of the first moving means 6 and is the other in the axial direction of the developing sleeve, for example, from the back side to the front side in the figure. It is moved and stirred toward. At this time, the so-called circulating conveyance in the longitudinal direction of the developing sleeve is achieved by the cooperative relationship between the first moving means 6 and the second moving means 7. [0009] More specifically, in FIG.
Reference numeral 0 denotes a U-shaped groove 61 having a substantially upper opening provided with a window 63 as a developer receiving port, an apron 64 for scraping the developer, and an opening 65 as a developer discharging port. . The window 63 is formed at the left end of the U-shaped groove 61 on the upstream side in the rotation direction of the developing sleeve 5 in the drawing.
4 is provided directly below the window 63. In this case, window 6
3 and the apron 64 are formed by forming a downward U-shaped slit on the side surface of the U-shaped groove 61, and then cutting and raising the slit. The opening 65 is formed in the bottom of the U-shaped groove 61 at the opposite side of the window 63 in the longitudinal direction. The left end of the U-shaped groove 61 in the drawing is slightly inward from the left end of the developing sleeve 5 in the drawing. [0010] The first moving means 6 comprises a screw 62 rotatably supported in a U-shaped groove 61. The second moving means 7 is disposed downstream of the first moving means 6 and extends vertically over the entire axial direction of the developing sleeve 5. A restricting member 7, which is an oblique plate extending obliquely downward to the upstream side of the peripheral surface of the sleeve 5 and disposed above the outer periphery of the developing sleeve 5.
2 and a large number of drift plates 7 erected on the regulating member 72.
It consists of three. The drift plate 73 is arranged obliquely to the direction of movement of the developer on the developing sleeve 5 and moves the developer in a direction opposite to the first moving means. In this case, as shown in the figure, the drift plate 73 is at an obliquely left position that is inclined leftward as it goes upward in the drawing, and as is apparent from FIG. It is important that the adjacent deflector plate overlaps the upper end 73b in the drawing as indicated by the symbol e in the vertical direction in the drawing. The inclination θ of the drift plate 73 is preferably 30 ° to 45 ° in view of the developer transportability. The second moving means 7 may have a configuration in which a drift plate is attached to a doctor blade. The lowermost edge of the transport path 10, that is, the U-shaped groove 61
It is important that the gap G1 (see FIG. 1) between the second moving means 7 and the gap G2 between the regulating member 72 and the developing sleeve 5 is larger than the gap G1 between the developing member 5 and the developing sleeve 5. As shown in FIG. 4, the relative position between the regulating member 72 on which the drift plate 73 is erected and the developing sleeve 5 is changed.
The magnetic force peak 8a of the magnetic force distribution line 8 on the surface is located slightly upstream from immediately below the lower edge of the drift plate 73, and the second magnetic force peak 8b is located further upstream of the magnetic force peak 8a. Is desirable. That is, it is desirable that a magnet that forms the magnetic peaks 8a and 8b be disposed inside the developing sleeve 5. With the above construction, the developer on the developing sleeve 5 is scraped off by the apron 64 and the window 6
3 is taken into the U-shaped groove 61. The developer introduced into the U-shaped groove 61 is pushed rightward in the figure in the axial direction of the developing sleeve 5 by the rotating screw 62, and falls onto the developing sleeve 5 from the opening 65. On the other hand, of the developer scraped off by the apron 64, all the agent that has not passed through the gap G 2 is scooped up by the regulating member 72. The developer that has fallen from the opening 65 is also scooped by the regulating member 72,
Due to the action of 3, it moves leftward in the figure along the axial direction. Then, the developer, which is scooped up one after another, stays in the agent pool and is stirred and frictionally charged, and is brought to the left end in the figure along the vertical plate 71 as a lump (not solidified). However, the left end of the U-shaped groove 61 is a vertical plate 71
The block-shaped developer which has been brought closer to the left end of the vertical plate 71 because it is moved inward from the left end enters the U-shaped groove on the upstream side, and is again axially moved by the screw 62 to the right side in the figure. Moved. In this way, the developing sleeve circulating stirring action in the longitudinal direction is achieved. FIGS. 5 and 6 show another embodiment of the present invention. In the embodiment shown in FIG. 5, the screw 37 as the second moving means is close to a part of the peripheral surface of the developing sleeve 5,
In addition, the developer that is arranged along the axial direction and moves the developer on the developing sleeve 5 substantially to the left in the drawing in the entirety thereof is raised on the left end of the developing sleeve 5 in the drawing. , Is moved rightward in the drawing of the transport path 30 disposed downstream from the screw 37. The configuration of the transport path 30 is substantially the same as that of the transport path 10 shown in FIG. 2, except that the upstream side of the right end of the U-shaped groove outside the figure is cut off instead of the opening 65. The developer moved rightward in the figure by the first moving means 6 falls from the cut-out portion and participates in the axial movement action of the screw 37. The embodiment shown in FIG. 6 has a configuration similar to that of the embodiment shown in FIG.
The window and apron are omitted in the U-shaped groove 41 that constitutes a part of
The structure at the left end of the U-shaped groove 41 in the drawing is positively received by the second moving means 7 so that the structure at the left end in the drawing is positively received by the second moving means. The notch 41 is formed in the U-shaped groove side plate on the second moving means 7 side.
a is provided. In this case, the developing sleeve 5
The upper developer moves to the left in the drawing except for the one supplied to the photoreceptor, and the developer collected at the left end is cut out 41a.
From the transport path 40 through the screw 62 of the first moving means 6 and is moved rightward in FIG.
2 and again participates in the axial moving action of the second moving means 7. FIG. 7 shows an example of a copying machine incorporating the present apparatus, and FIG. 8 shows a timing chart of each component of the copying machine. In these figures, a document 10 is placed on a contact glass 101 disposed above a copying machine 100.
2 is placed and a copy button (not shown) is pressed,
The developing motor M (see FIG. 1), the photoconductor motor and the fixing unit motor are driven simultaneously. Next, the paper feed roller 10
3 rotates to feed the transfer sheet 104 to a predetermined position. Further, when the original light image illuminated by the exposure lamp 105 is applied to the photoreceptor 1 via the optical system 108, the photoreceptor 1 uniformly charged by the main charger 106
An electrostatic latent image is formed on the surface, and is visualized by the operation of the developing device 2 of the present invention. This visible image is transferred to the transferred transfer sheet 104 by the action of the transfer charger 107, and is discharged outside the apparatus as a copy via the fixing unit. According to the present invention, as is apparent from the above description, even if the pumping roller is omitted, in the longitudinal direction of the developing sleeve, from one moving means to the other moving means, and further to the original moving means. And the developer are circulated and agitated, so there is no need to adjust the amount of movement of the various moving means, the developer is not stored side-by-side , and the toner is
By directly replenishing the developer carried on the toner cartridge
When the toner density in the axial direction of the developing sleeve during supply is
Controls the developer on the developing sleeve
And agitated in the axial direction to eliminate
Efficient toner density unevenness in the axial direction of the fed developer
It can be prevented well .

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a configuration diagram in one embodiment of the present invention. FIG. 2 is a perspective view of a main part in one embodiment of the present invention. FIG. 3 is a diagram for explaining an inclination of a drift plate in one embodiment of the present invention. FIG. 4 is a diagram for explaining a relative position between a drift plate and a magnetic force peak. FIG. 5 is a perspective view of a main part according to another embodiment of the present invention. FIG. 6 is a perspective view of a main part in another embodiment of the present invention. FIG. 7 is a configuration diagram showing a copier incorporating a developing device according to the present invention. FIG. 8 is an operation timing chart of components constituting a copying machine incorporating the developing device according to the present invention. [Description of Symbols] 5 Developing sleeve 6 First moving means 7 Second moving means 10 Transport path 72 Restriction member 73 Non-uniform plate

Continuation of front page       (56) References JP-A-60-75852 (JP, A)                 JP-A-61-212864 (JP, A)                 Shokai 57-5959 (JP, U)                 Shokai Sho 61-29362 (JP, U)                 Shokai Sho 61-101762 (JP, U)

Claims (1)

(57) [Claims] A developing sleeve that rotates while adhering a developer including a carrier and a toner; a toner replenishing unit that directly replenishes the toner carried on the developer carried on the developing sleeve; a regulating unit that regulates the developer on the developing sleeve And the toner concentration in the developer provided between the toner replenishing means and the regulating means in the rotation direction of the developing sleeve.
For a uniform degree, above around the developing sleeve developer first moving means for moving in a first direction in the axial direction of the developing sleeve and, said first developer which has moved to the first direction Second moving in a second direction opposite to the first direction
And a moving means.