JP2004109746A - Development device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To avoid compression of toner and to suitably supply toner from a toner container 6 to a processing laboratory 14 in accordance with reduction of toner in the processing laboratory 14. <P>SOLUTION: A development device 2 is provided with a stir transport means 28 arranged in the processing laboratory 14 and the toner container 6. The processing laboratory 14 has first and second transport paths 26a and 26b and communicating paths 27a and 27b. The stir transport means 28 is provided with a first rotation helical blade member 30a of the first transport path 26a and a second rotation helical blade member 30b of the second transport path 26b. A toner reception opening 54 positioned above a toner reception region of the first transport path 26a is formed in the processing laboratory 14. A toner discharge opening 62 is formed in the toner container 6. Transport capacity of the first rotation helical blade member 30a can be made lower than that of the second rotation helical blade member 30b. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a developing device for developing an electrostatic latent image into a toner image used in an electrostatic image forming machine such as an electrostatic printer, a copying machine and a facsimile, and more specifically, a toner container or a toner hopper. The present invention relates to a developing device in which a toner discharge opening substantially above the toner receiving opening is formed so as to communicate with the toner receiving opening when toner can be supplied to the developing chamber.
[0002]
[Prior art]
The developing device of the above-described embodiment has been developed by the present applicant, Kyocera Mita Corporation, and has already been filed (see Patent Document 1). The developing device includes a housing having a developing chamber that defines a toner circulation path, a stirring and conveying unit disposed in the development chamber for conveying the toner through the circulation path while stirring, and developing the toner in the development chamber. A toner application unit for applying an electrostatic latent image to be provided, and a toner container detachably mounted on a housing for replenishing toner into the developing chamber. The developing chamber has a toner receiving opening located above the toner receiving area in the circulation path. The toner container includes a toner container case containing toner. The toner container case has a toner discharge opening that is located above and opposed to the toner receiving opening when the toner container is mounted on the housing. The toner container includes a toner conveying unit that conveys the toner stored in the toner container case toward the toner discharge opening. The transport capacity of the stirring transport unit provided in the developing chamber is locally reduced on the downstream side of the toner receiving area.
[0003]
In the above-mentioned developing device, the conveying capacity of the stirring and conveying means for conveying the toner through the circulation path defined in the developing chamber while stirring the toner is located on the downstream side of the toner receiving area where the toner receiving opening is disposed above. Because of the local reduction, toner stagnation is generated in the toner receiving area. Such an amount of staying toner fluctuates according to the amount of toner in the developing chamber. The replenishment of toner from the toner container to the developing chamber does not depend directly on the drive control of the toner conveying means of the toner container, but is automatically performed in accordance with the amount of accumulated toner in the toner receiving area, and therefore in accordance with the amount of toner in the developing chamber. Is controlled.
[0004]
[Patent Document 1]
JP 2001-235933 A (Claims 1 to 3, FIGS. 3 and 4)
[0005]
[Problems to be solved by the invention]
In the above-described conventional developing device, the amount of toner supplied to the developing chamber is controlled by controlling the driving of the toner conveying means of the toner container based on a detection signal from a toner amount detection sensor provided in the developing chamber. Need not be controlled, a dedicated driving source for driving the sensor and the toner conveying means of the toner container is not required. Therefore, although the manufacturing cost can be reduced, the toner in the developing chamber is reduced. Therefore, it is possible to appropriately supply the toner from the toner container to the developing chamber in accordance with the above-mentioned condition. However, on the other hand, the toner is lifted in the toner receiving area where the toner discharge opening of the toner container is located above, and the stagnation is locally generated, so that the toner tends to be pressed, and the toner aggregates in the toner receiving area. Alternatively, there is a possibility that blocking may be generated and smooth flow of the toner may be hindered.
[0006]
It is an object of the present invention to avoid excessive pressure of toner in the toner receiving area, and to eliminate the need for a dedicated drive source for driving the toner conveying means in the toner container, thus sufficiently reducing the manufacturing cost. It is an object of the present invention to provide a new and improved developing device capable of appropriately replenishing toner from a toner container to a developing chamber in response to a decrease in toner in the developing chamber.
[0007]
[Means for Solving the Problems]
According to the present invention, a housing having a developing chamber that defines a toner circulation path, a stirring and conveying unit disposed in the development chamber for conveying the toner through the circulation path while stirring the toner, A first conveying unit extending in parallel with the toner applying unit, including a toner applying unit for applying the electrostatic latent image to be developed, and a toner replenishing unit for replenishing the toner into the developing chamber; Path, a second conveyance path extending along the first conveyance path and the toner application unit, and a communication path communicating between both end regions of the first and second conveyance paths. Wherein the stirring and conveying means includes a first stirring and conveying means disposed on the first conveying path, and a second stirring and conveying means disposed on the second conveying path. Positioned above a toner receiving area set in a partial area of the first transport path. A toner discharge opening which is located substantially above the toner receiving opening so as to communicate with the toner receiving opening when the toner can be supplied into the developing chamber. Developing device,
The transport capacity of the first stirring and transporting means is lower than the transporting capacity of the second stirring and transporting means.
A developing device is provided.
Preferably, the toner supply means is a toner container detachably mounted on the housing.
The first stirring and conveying means includes a first rotating spiral blade member extending along the first conveying path and including spiral blades, and the second stirring and conveying means extends along the second conveying path. And a pitch of the spiral blades of the first rotary spiral blade member is defined to be smaller than a pitch of the spiral blades of the second rotary spiral blade member. Is preferred.
The first stirring and conveying means includes a first rotating spiral blade member extending along the first conveying path and including spiral blades, and the second stirring and conveying means extends along the second conveying path. It is preferable that the rotation speed of the first rotation spiral blade member is set lower than the rotation speed of the second rotation spiral blade member. .
The first stirring and conveying means includes a first rotating spiral blade member extending along the first conveying path and including spiral blades, and the second stirring and conveying means extends along the second conveying path. The first rotating spiral blade member is provided with a second rotating spiral blade member that includes the second rotating spiral blade member, and the outer diameter of the spiral blade is defined to be smaller than the outer diameter of the spiral blade of the second rotating spiral blade member. Is preferable.
The first stirring and conveying means extends along the first conveying path and includes a first rotating spiral blade member including a central shaft and a spiral blade, and the second stirring and conveying means includes a second conveying path. And a second rotating spiral blade member including a central shaft portion and a spiral blade, the outer diameter of the central shaft portion of the first rotating spiral blade member being the center of the second rotating spiral blade member. It is preferable that the diameter be larger than the outer diameter of the shaft portion.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, preferred embodiments of a developing device configured according to the present invention will be described in more detail with reference to the accompanying drawings.
[0009]
1 and 2 show a preferred embodiment of a developing device constituted according to the present invention. The illustrated developing device, generally designated by reference numeral 2, comprises a developing device main body 4, a toner replenishing means, and a toner container 6 in the embodiment.
[0010]
The developing device main body 4 includes a housing 8, and the housing 8 includes a housing main body 10 and an upper wall member 12 mounted on the housing main body 10. In the left half of FIG. 1 of the housing body 10 which can be molded from an appropriate synthetic resin, a developing chamber 14 having an open upper surface (more specifically, a main portion excluding a left edge) and a left side surface is provided. Stipulated. The housing body 10 has a bottom wall 16, side walls 18 and 20, and a connecting wall 22. The connecting wall 22 extends between the upper edges of the left and right side walls 18 and 20 in FIG. The bottom wall 16 of the housing body 10 has three arc-shaped portions 16a, 16b, and 16c arranged in parallel and having a circular cross-sectional shape. A partition 24 extending substantially vertically upward is formed between the arc portion 16a and the arc portion 16b. On both sides of the partition 24, the first transport path 26a and the second transport path 26a, which are linear paths, are respectively provided. The transport path 26b is defined. Both ends of the partition 24 are separated from the inner surfaces of the side walls 18 and 20 of the housing body 10, and a required gap exists between both ends of the partition 24 and the inner surfaces of the side walls 18 and 20.
[0011]
A gap between one end (the right end in FIG. 2) of the partition wall 24 and the side wall 18 is a communication path that communicates with one end area (the right end area in FIG. 2) of each of the first transport path 26a and the second transport path 26b. 27a, and a gap between the other end (the left end in FIG. 2) of the partition wall 24 and the side wall 20 is formed in the other end region (FIG. 2) of each of the first transport path 26a and the second transport path 26b. At the left end area). Therefore, the first transport path 26a and the second transport path 26b extending in parallel with each other are communicated with each other via the communication paths 27a and 27b at both end regions, and thus the first transport path 26a , And then from the one end area of the first conveyance path 26a to the one end area of the second conveyance path 26b via the communication path 27a, extend along the second conveyance path 26b, and An endless circulation path extending from the other end area of the path 26b to the other end area of the first transport path 26a is defined (the toner is circulated through the circulation path as will be further described later). In other words, the circulation path is formed by a first conveyance path 26a extending in parallel with the toner application unit 40 described later, and a first conveyance path 26a between the first conveyance path 26a and the toner application unit 40. A second conveying path 26b extending along the toner applying means 40; and communication paths 27a and 27b communicating between both end areas of the first conveying path 26a and the second conveying path 26b. .
[0012]
In the circulation path described above, a stirring and conveying means 28 for conveying the toner through the circulation path while stirring the toner is provided. The stirring and conveying means 28 in the illustrated embodiment is a first stirring and conveying means disposed on the first conveying path 26a and extending along the first conveying path 26a, and in the embodiment, a first rotating spiral. A blade member 30a and a second stirring / transporting means disposed in the second transport path 26b and extending along the second transport path 26b, and in the embodiment, a second rotary spiral blade member 30b. Have been. The first rotating spiral blade member 30a, which can be molded from an appropriate synthetic resin, has a central shaft portion 32a and a spiral blade 34a. Similarly, the second rotary spiral blade member 30b, which can be molded from an appropriate synthetic resin, also has a central shaft portion 32b and a spiral blade 34b. The first rotary spiral blade member 30a is rotatably mounted between the side walls 18 and 20 of the housing body 10, and extends linearly along the first transport path 26a. The second rotary spiral blade member 30b is also rotatably mounted between the side walls 18 and 20 of the housing body 10, and extends linearly along the second transport path 26b. One end (right end in FIG. 2) of the central shaft portion 32a of the first rotary spiral blade member 30a and one end (right end in FIG. 2) of the central shaft portion 32b of the second rotary spiral blade member 30b are side walls 18. The input gears 32c and 32d are fixed to these protruding ends, respectively. When the developing device 2 is mounted at a predetermined position of the image forming machine, the input gear 32c of the first rotary spiral blade member 30a and the input gear 32d of the second rotary spiral blade member 30b mesh with a transmission gear (not shown). And a drive connection (not shown), which may be an electric motor. When a driving source (not shown) is energized, the first rotating spiral blade member 30a and the second rotating spiral blade member 30b respectively have the same rotational speed R1 in the same direction indicated by an arrow 36 in FIGS. (R.p.m.) and R2 (r.p.m.).
[0013]
As can be clearly understood by referring to FIG. 2, the spiral blades 34a of the first rotating spiral blade member 30a and the spiral blades 34b of the second rotating spiral blade member 30b have so-called spiral directions set in opposite directions. By rotating the first spiral blade member 30a in the direction indicated by the arrow 36, the toner is transported in the direction indicated by the arrow 37 through the first transport path 26a, and the second rotary spiral blade member 30b is rotated. By being rotated in the direction indicated by the arrow 36, the toner is conveyed in the direction indicated by the arrow 38 through the second conveyance path 26b. A toner receiving area is set in the first transport path 26a. The toner is introduced into the toner receiving area through a toner receiving opening 54 (shown by a two-dot chain line in FIG. 2) described in detail later. As described above, the toner conveying capacity of the first rotary spiral blade member 30a provided in the first conveying path 26a in which the toner receiving area in which the toner is introduced through the toner receiving opening 54 is set, extends over the entire area. The toner conveying capacity of the second rotary spiral blade member 30b provided in the second conveying path 26b is also substantially constant. The toner transfer capability of the first rotary spiral blade member 30a (that is, the toner transport capability of the entire first rotary spiral blade member 30a) is equal to the toner transport capability of the second rotary spiral blade member 30b (that is, the first rotary spiral blade member 30b has the same toner transport capability). It is important that the rotation speed is smaller than that of the second rotary spiral blade member 30b.
[0014]
In the illustrated embodiment, the diameter r1 of the central shaft portion 32a of the first rotary spiral blade member 30a, the diameter r2 of the central shaft portion 32b of the second rotary spiral blade member 30b, and the spiral of the first rotary spiral blade member 30a. The diameter D1 of the blade 34a and the diameter D2 of the spiral blade 34b of the second rotating spiral blade member 30b are substantially the same over the entire area (r1 = r2, D1 = D2), respectively. The pitch P1 of the spiral blades 34a of the rotating spiral blade member 30a (constant over the entire region) is defined to be smaller than the pitch P2 of the spiral blades 34b of the second rotating spiral blade member 30b (constant over the entire region) ( P1 <P2). As described above, since the first rotary spiral blade member 30a and the second rotary spiral blade member 30b are rotationally driven at substantially the same rotation speed (R1 = R2), the first stirring is performed. The transporting means, that is, the toner transporting ability (transporting speed) of the entire first rotary spiral blade member 30a is the second stirring transporting means, that is, the toner transporting ability (transporting speed) of the entire second rotary spiral blade member 30b. Is reduced. The function and effect of the first rotary spiral blade member 30a having a toner transporting capability smaller than the toner transporting capability of the second rotary spiral blade member 30b will be described later.
[0015]
Above the arc-shaped portion 16c of the bottom wall 6 of the housing body 10, a toner applying unit 40 is disposed. The toner applying means 40 includes a developing sleeve 41 rotatably mounted between the side walls 18 and 20 of the housing body 10. In the developing sleeve 41, a stationary permanent magnet (not shown) is arranged. One end of the rotating shaft 42 to which the developing sleeve 41 is fixed projects through the side wall 18 and an input gear 43 is fixed to the projecting end. When the developing device 2 is mounted at a predetermined position of the image forming machine, the input gear 43 is meshed with one of transmission gears (not shown) and is drivingly connected to a drive source (not shown) which may be an electric motor. This drive source is a drive source common to the drive sources of the first and second rotary spiral blade members 30a and 30b. Therefore, when this driving source is energized, the developing sleeve 41 is rotated in the direction indicated by the arrow 39. An ear cutting means 44 is provided in association with the developing sleeve 41. In the developing chamber 14, a one-component developer composed of only toner is stored, and the developer, that is, the toner, is rotated in a direction indicated by an arrow 36 in a first rotating spiral blade member 30a and a second rotating spiral blade member. By the operation of 30b, the sheet is circulated and conveyed through the circulation path. The toner applying unit 40 holds the toner on the peripheral surface of the developing sleeve 41 rotated in the direction indicated by the arrow 39, and conveys the toner through the developing area 45. The ear cutting means 44 regulates the layer thickness of the toner held on the peripheral surface of the developing sleeve 41 and conveyed to the developing area 45. In the development zone 45, the toner is applied to the electrostatic latent image to be developed, thus developing the electrostatic latent image into a toner image.
[0016]
The upper wall member 12 is mounted on the housing body 10. The upper wall member 12 has an upper wall 50 that covers the upper surface of the developing chamber 14. An elongated immersion area 52 extending in the width direction (the direction perpendicular to the paper surface in FIG. 1) is formed on the upper surface wall 50. The cross-sectional shape of the immersion area 52 is arc-shaped. In the immersion area 52, a toner receiving opening 54, which may be rectangular, is formed. The toner receiving opening 54 is positioned above and opposed to a toner receiving area set in the first transport path 26a. The toner receiving opening 54 is positioned above and opposed to a toner receiving area set in the first transport path 26a. A developing chamber shutter (not shown) is provided on the upper wall 50, and the toner receiving opening 54 can be opened and closed by selectively moving the developing chamber shutter between an open position and a closed position.
[0017]
In the illustrated embodiment, the toner container 6 constituting the toner supply means includes a toner container case 60. The toner container case 60 includes a box-shaped toner container main body 61 having an open upper surface, and a lid 62 fixed to the toner container main body 61 by an appropriate means such as ultrasonic welding. The bottom wall of the toner container main body 61 has two arc-shaped portions 61a and 61b whose cross-sectional shapes are arc-shaped. The radius of curvature of the arc-shaped portion 61a is relatively large, and the radius of curvature of the arc-shaped portion 61b is relatively small. The radius of curvature of the arc-shaped portion 61b corresponds to the radius of curvature of the immersion area 52 defined on the upper surface wall 50 of the upper surface wall member 12 described above. The arc-shaped portion 61b has a toner discharge opening 62 which may be rectangular. When the toner container 6 is mounted on the housing 8 as required, the arc-shaped portion 61b of the toner container main body 61 is positioned opposite to the immersion area 52 defined on the upper surface wall 50 of the upper surface wall member 12, and A toner discharge opening 62 is located above the receiving opening 54. To avoid so-called blocking of the toner near the toner discharge opening 62 and / or the toner receiving opening 54, the width and the length of the toner discharge opening 62 are substantially equal to the width and the length of the toner receiving opening 54. Preferably it is the same or somewhat smaller.
[0018]
The toner container main body 61 has a pair of side walls 63 spaced from each other in a direction perpendicular to the plane of FIG. 1 (only one side wall 63 is shown in FIG. 1). A circular opening (not shown) is formed in the other side wall 63, and the toner is filled into the toner container case 60 through the opening. After the toner is filled into the toner container case 60, a closing member (not shown) is fixed to the opening, and the opening is closed. Between both side walls 63 of the toner container main body 61, a toner conveying means 64 extending along the arc-shaped portion 61a and a toner conveying means 65 extending along the arc-shaped portion 61b are provided. The toner conveying means 64 includes a rotation support shaft 64a rotatably mounted between the side walls 63, and a plurality of rectangular conveyance pieces 64b fixed to the rotation support shaft 64a. Each of the transporting pieces 64b can be formed from an appropriate synthetic resin film or sheet. One end of the rotation support shaft 64a protrudes through one side wall 63, and an input gear (not shown) is fixed to the one end.
[0019]
The toner conveying means 65 is constituted by a rotary spiral blade member having a central shaft portion 65a and a spiral blade 65b. One end of the central shaft portion 65a protrudes through one side wall 63, and an input gear (not shown) is fixed to the one end. This input gear is meshed with the input gear of the toner conveying means 64. When the toner container 6 is mounted on the housing 8 as required, the input gear of the toner conveying means 65 is connected to the input gear 32c of the first rotary spiral blade member 30a and the input gear 32d of the second rotary spiral blade member 30b. It is meshed with one of the transmission gears for drivingly connecting the drive source (not shown). Therefore, when the driving source is energized, the first rotating spiral blade member 30a, the second rotating spiral blade member 30b, and the developing sleeve 41 disposed in the developing chamber 14 as described above move the arrow 36 and the developing sleeve 41, respectively. In addition to being rotated in the direction indicated by 39, the toner conveying means 64 and 65 of the toner container 6 are also rotated in the directions indicated by arrows 66 and 67, respectively. When the toner conveying means 64 is rotated in the direction indicated by the arrow 66, the toner present on the arc portion 61a is conveyed onto the arc portion 61b by the action of the conveying piece 64b, and the toner conveying means 65 is moved in the direction indicated by the arrow 67. , The toner on the arc-shaped portion 61b is conveyed toward the toner discharge opening 62. It should be noted that the illustrated embodiment constructed according to the present invention does not require a dedicated drive source for rotating the toner transport means 64 and 65 of the toner container 6.
[0020]
A container shutter 70 is provided in the toner container case 60. Both ends of the container shutter 70 have a cylindrical shape, and a shutter portion 72 located at an intermediate portion has an arc shape covering an angle range of approximately 200 degrees. The shutter portion 72 has a toner passage opening 74 which may be rectangular. The size of the toner passage opening 74 may be substantially the same as the toner discharge opening 62 formed in the toner container main body 61. A seal member 76, which may be rectangular and extends along the toner passage opening 74, is attached to the outer peripheral surface of the shutter section 72. Conveniently, the size of the seal member 76, which can be formed from a flexible material such as a sponge, is somewhat larger than the toner discharge opening 62 described above. The container shutter 70 is disposed in the arc-shaped portion 61b of the toner container main body 61, and the toner conveying means 65 extends through both ends of the container shutter 70. A turning operation member (not shown) is rotatably disposed on the other side wall 63 of the toner container main body 61, and one end of the turning operation member is connected to one end of the container shutter 70 in the axial direction, and the other end is a toner It projects outward from the other side wall 63 of the container body 61. By turning the turning operation member from the outside of the toner container main body 61, the container shutter 70 is aligned with a closed position (not shown) that closes the toner discharge opening 62 and the toner passage opening 74 is aligned above the toner discharge opening 62. It can be pivoted to any of the positioned open positions (see FIG. 1). When the toner container 6 is not detachably mounted on the housing 8 of the developing device main body 4 (in other words, when the toner supply into the developing chamber 14 is not possible), the container shutter 70 is located at the closed position. . When the container shutter 70 is located at the closed position, the seal member 76 seals and closes the toner discharge opening 62, so that leakage of toner is sufficiently reliably prevented.
[0021]
As shown in FIG. 1, the toner container 6 is detachably mounted on a housing 8 of the developing device main body 4. When the developer container shutter (not shown) is moved to the open position to open the toner receiving opening 54 and the toner container 6 is mounted at a required position of the housing 8, the toner discharging opening 62 of the toner container main body 61 and the upper wall member 12 are opened. Are aligned in the up-down direction via the container shutter 70. After the toner container 6 is mounted at a required position of the housing 8, the turning operation member is operated to position the container shutter 70 at the open position. As shown in FIG. 1, the toner passage opening 74 of the container shutter 70 is aligned with the toner discharge opening 62 of the toner container main body 61, and the toner discharge opening 62 is opened. As a result, the toner container 6 constituting the toner replenishing unit is in a state where the toner can be replenished into the developing chamber 14. Therefore, the toner in the toner container case 60 is supplied into the developing chamber 14 through the toner passage opening 74, the toner discharge opening 62, and the toner receiving opening 54. The supply of toner will be further described later.
[0022]
In the illustrated developing device having the above-described configuration, the developing chamber 14 is filled with a so-called one-component developer composed of only toner. When the development is performed, the toner is applied to the electrostatic latent image by the toner application unit 40, so that the toner is consumed according to the development. Therefore, it is important to appropriately supply the toner into the developing chamber 14 in accordance with the consumption of the toner. In the illustrated developing device configured according to the present invention, a dedicated driving source for selectively rotating the toner conveying means 64 and 65 provided in the toner container 6 as needed is not required, Supply of toner from the toner container 6 to the developing chamber 14 is appropriately controlled. More specifically, in the illustrated developing device constructed in accordance with the present invention, the above-mentioned driving source (not shown) is energized in order to perform development, and the stirring and conveying means 28 (that is, the first rotary spiral) together with the toner applying means 40 are applied. When the blade member 30a and the second rotary spiral blade member 30b) are rotated, the toner conveying means 64 and 65 of the toner container 6 are also connected to the driving source. As a result, the toner is conveyed toward the toner passage opening 74 and the toner discharge opening 62 in the toner container case 60.
[0023]
On the other hand, in the developing chamber 14, the transfer capability of the first rotary spiral blade member 30a provided in the first transfer path 26a, which constitutes the stirring transfer means 28, is provided in the second transfer path 26b. The toner carrying capacity of the second rotary spiral blade member 30b is reduced. Therefore, a stagnation of toner is generated in the entire area of the first transport path 26a. In other words, the toner level in the first transport path 26a is set higher than the toner level in the second transport path 26b. The amount of staying toner in the first transport path 26a tends to be larger in the upstream area where the toner receiving area where the toner discharge opening 54 is located is set than in the downstream area of the first transport path 26a. Such stagnation of the toner suppresses the toner from entering the developing chamber 14 through the toner receiving opening 54. The amount of staying toner in the toner receiving area varies according to the amount of toner in the developing chamber 14. Therefore, the degree of suppression of the entry of the toner into the developing chamber 14 is varied depending on the amount of the toner in the developing chamber 14, and when the amount of the toner decreases, the introduction of the toner into the developing chamber 14 increases, and when the amount of the toner increases, The introduction of toner into the developing chamber 14 is reduced. Thus, the supply of toner to the developing chamber 14 is appropriately controlled without directly depending on the drive control of the toner conveying means 64 and 65 of the toner container 6. As described above, since the amount of staying toner in the first transport path 26a tends to be larger in the upstream area than in the downstream area of the first transport path 26a, the toner receiving area where the toner discharge opening 54 is located Is preferably disposed in an upstream area of the first transport path 26a.
[0024]
Therefore, according to the developing device according to the present invention, unlike in the above-described conventional device, the stagnation is not locally generated in the toner receiving area where the toner discharge opening 54 of the toner container 6 is located. In other words, the first rotary spiral blade member 30a in the first transport path 26a in which the toner receiving area is set has its toner transport capability reduced as a whole, so that the first rotary spiral present at a position distant from the toner receiving area. Since the stagnation of the toner is started from the upstream end of the blade member 30a, the pressure acting on the toner can be dispersed, and the local excessive pressing of the toner can be avoided. As a result, aggregation or blocking of the toner is not generated and the smooth flow of the toner is not hindered. Therefore, the toner is appropriately transferred from the toner container 6 to the developing chamber 14 according to the decrease of the toner in the developing chamber 14. Can be replenished. That is, according to the present invention, a dedicated driving source for driving the toner conveying means 64 and 65 in the toner container 6 is not required while reliably avoiding excessive pressure of the toner, and therefore, the production cost is sufficiently reduced. Can be appropriately supplied from the toner container 6 to the developing chamber 14 in accordance with the decrease in the toner in the developing chamber 14. In the above-described embodiment, the toner receiving area is set at a position downstream of the most upstream position of the first transport path 26a. However, the toner receiving area may be set at the most upstream position or a position in the vicinity thereof. In the embodiment, substantially the same operation and effect as described above can be obtained.
[0025]
When the toner in the toner container case 60 is exhausted, the toner container 6 needs to be replaced. In this case, the turning operation of the turning operation member is performed from outside the toner container main body 61 to position the container shutter 70 at the closed position for closing the toner discharge opening 62, and then the toner container 6 is moved to the housing of the developing device main body 4. 8 can be disengaged. Next, the developing chamber shutter (not shown) is moved from the open position to the closed position, and thus the toner receiving opening 54 of the developing chamber 14 is closed. After the toner container 6 is detached from the housing 8, a new toner container 6 can be mounted on the housing 8 by the above-described procedure. By turning the turning operation member, the container shutter 70 is positioned at the open position and the toner discharge opening 62 is opened. Thus, the toner can be appropriately supplied from the new toner container 6 into the developing chamber 14.
[0026]
In the developing device 2 according to the present invention, it is important that the transport capability of the first rotary spiral blade member 30a is lower than the transport capability of the second rotary spiral blade member 30b. In the above embodiment, the pitch P1 of the spiral blades 34a of the first rotary spiral blade member 30a is defined to be smaller than the pitch P2 of the spiral blades 34b of the second rotary spiral blade member 30b (P1 < P2) may be replaced by other embodiments as described below.
[0027]
In the first other embodiment, the rotation speed R1 (rpm) of the first rotary spiral blade member 30a is equal to the rotation speed R2 (rpm) of the second rotary spiral blade member 30b. (R1 <R2). In this embodiment, the diameter r1 of the central shaft portion 32a of the first rotary spiral blade member 30a, the diameter r2 of the central shaft portion 32b of the second rotary spiral blade member 30b, the spiral blade of the first rotary spiral blade member 30a. The diameter D1 of the first rotating spiral blade member 30b, the pitch D1 of the spiral blade 34a of the first rotating spiral blade member 30a, and the diameter D1 of the second rotating spiral blade member 30b, and the pitch P1 of the spiral blade 34a of the second rotating spiral blade member 30b. The pitches P2 are substantially the same (r1 = r2, D1 = D2, P1 = P2). Even with such a configuration, it is possible to reduce the transport capability of the first rotary spiral blade member 30a compared to the transport capability of the second rotary spiral blade member 30b.
[0028]
In the second other embodiment, the outer diameter D1 of the spiral blade 34a of the first rotating spiral blade member 30a is defined to be smaller than the outer diameter D2 of the spiral blade 34b of the second rotating spiral blade member 30b. (D1 <D2). In this embodiment, the diameter r1 of the central shaft portion 32a of the first rotary spiral blade member 30a, the diameter r2 of the central shaft portion 32b of the second rotary spiral blade member 30b, the spiral blade of the first rotary spiral blade member 30a. The pitch P1 of the first rotating spiral blade member 30a, the pitch P2 of the second rotating spiral blade member 30b, the pitch P2 of the second rotating spiral blade member 30b, the rotation speed R1 (rpm) of the first rotating spiral blade member 30a, and the second rotating spiral blade member 30b. The rotation speeds R2 (rpm) are substantially the same (r1 = r2, P1 = P2, R1 = R2). Even with such a configuration, it is possible to reduce the transport capability of the first rotary spiral blade member 30a compared to the transport capability of the second rotary spiral blade member 30b.
[0029]
In the third other embodiment, the outer diameter r1 of the central shaft portion 32a of the first rotary spiral blade member 30a is larger than the outer diameter r2 of the central shaft portion 32b of the second rotary spiral blade member 30b. (R1> r2). In this embodiment, the outer diameter D1 of the spiral blade 34a of the first rotary spiral blade member 30a, the outer diameter D2 of the spiral blade 34b of the second rotary spiral blade member 30b, and the spiral blade of the first rotary spiral blade member 30a. The pitch P1 of the first rotating spiral blade member 30a, the pitch P2 of the second rotating spiral blade member 30b, the pitch P2 of the second rotating spiral blade member 30b, the rotation speed R1 (rpm) of the first rotating spiral blade member 30a, and the second rotating spiral blade member 30b. The rotation speeds R2 (rpm) are substantially the same (D1 = D2, P1 = P2, R1 = R2). Even with such a configuration, it is possible to reduce the transport capability of the first rotary spiral blade member 30a compared to the transport capability of the second rotary spiral blade member 30b.
[0030]
In the above embodiment according to the present invention, in order to show the features of the present invention as simply and clearly as possible, the lock means for releasably locking the toner container 6 and the upper wall member 12 including the developing chamber shutter, and The configuration of the toner container 6 and the like including the container shutter 70 is shown in a minimally simplified form. However, as for the configuration of each of the above members except for the configuration that constitutes the feature of the present invention described above, basically, the configuration disclosed in Patent Document 1 introduced above may be used. Is described in Patent Literature 1, and thus will be left to that description and will be omitted in the present specification and drawings. Further, in the above-described embodiment, the toner replenishing unit for replenishing the toner into the developing chamber 14 includes the toner container 6 detachably mounted on the housing 8, but is not limited to this. The toner container 6 may be detachably attached to the housing 8 and / or the image forming apparatus main body. Further, another toner replenishing means, for example, a toner hopper which is mounted on the housing 8 and / or the image forming apparatus main body and replenishes the toner when the stored toner is exhausted may be used. In any form of toner replenishing means, in a state where the toner can be replenished into the developing chamber 14, the toner receptive opening 54 or substantially the same as the toner receptive opening so as to communicate with the toner receptive opening corresponding thereto. It is essential that a toner discharge opening 62 located above the corresponding toner receiving opening or a toner discharge opening corresponding thereto is formed. When the toner replenishing means is composed of at least a toner container 6 or a toner hopper mounted on the image forming apparatus main body, the toner replenishing unit is positioned at a required position where toner replenishment into the developing chamber 14 can be performed. The toner discharge opening 62 or the corresponding toner discharge opening is positioned above the toner receiving opening 54 or the corresponding toner receiving opening so as to communicate with the toner receiving opening 54 or the corresponding toner receiving opening. This is generally the case. However, even in the upper position, the position may be shifted in the horizontal direction on the layout. In this case, a proper communication path between the toner discharge opening 62 or the corresponding toner discharge opening and the toner receiving opening 54 or the corresponding toner receiving opening, that is, an appropriate communication path allowing the toner to freely fall. It goes without saying that a communication path is provided. As can be easily understood from the above description, in the developing device of the present invention, “provided with a toner replenishing unit for replenishing toner in the developing chamber” means that the toner replenishing unit is directly mounted on the developing device main body 4. Either the embodiment, an embodiment in which the toner replenishing unit is mounted or disposed on the image forming machine main body, or an embodiment in which the toner replenishing unit is mounted across the image forming machine main body and the developing device main body 4. Is also included.
[0031]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to the developing device by this invention, while avoiding excessive compression of a toner reliably, it does not require the exclusive drive source for driving the toner conveyance means in a toner container, and therefore reduces production cost sufficiently. However, the toner can be appropriately supplied from the toner container to the developing chamber in accordance with the decrease in the toner in the developing chamber.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view illustrating a preferred embodiment of a developing device configured according to the present invention.
FIG. 2 is a plan view of a developing device main body in the developing device shown in FIG.
[Explanation of symbols]
2 Developing device
4 Developing device body
6 Toner container
8 Housing
14 Developing room
24 partition
26a First transport path
26b Second transport path
27a, 27b communication passage
28 Stirring and conveying means
30a First rotating spiral blade member (first stirring and conveying means)
32a center shaft
34a spiral blade
30b Second rotating spiral blade member (second stirring and conveying means)
32b center shaft
34b spiral blade
40 Toner application means
54 Toner receiving opening
61 Toner container body
62 Toner discharge opening

Claims (6)

A housing having a developing chamber for defining a toner circulation path, a stirring and conveying means provided in the development chamber for conveying the toner through the circulation path while stirring, and an electrostatic latent image for developing the toner in the development chamber. A toner supply unit for applying toner to the image; and a toner supply unit for supplying toner to the developing chamber. The circulation path includes a first conveyance path extending in parallel with the toner application unit, and a first conveyance path. A second conveyance path extending along the conveyance path and the toner application unit along the communication path; and a communication path communicating between both end regions of the first and second conveyance paths. A first stirring / transporting means disposed on the first conveyance path, and a second stirring / conveying means disposed on the second conveyance path. Toner receiving located above the toner receiving area set in some areas An opening is formed in the toner supply means, and a toner discharge opening substantially above the toner receiving opening is formed so as to communicate with the toner receiving opening when the toner can be supplied into the developing chamber. In the device,
The transport capacity of the first stirring and transporting means is lower than the transporting capacity of the second stirring and transporting means.
A developing device, comprising: The developing device according to claim 1, wherein the toner replenishing means is a toner container detachably mounted on the housing. The first stirring and conveying means includes a first rotating spiral blade member extending along the first conveying path and including spiral blades, and the second stirring and conveying means extending along the second conveying path. And the pitch of the spiral blades of the first rotating spiral blade member is defined to be smaller than the pitch of the spiral blades of the second rotating spiral blade member. The developing device according to claim 1. The first stirring and conveying means includes a first rotating spiral blade member extending along the first conveying path and including spiral blades, and the second stirring and conveying means extends along the second conveying path. 2. The rotating spiral blade member includes a second rotating spiral blade member that includes a rotating spiral blade member, and a rotation speed of the first rotating spiral blade member is defined to be lower than a rotation speed of the second rotating spiral blade member. Or the developing device according to claim 2. The first stirring and conveying means includes a first rotating spiral blade member extending along the first conveying path and including spiral blades, and the second stirring and conveying means extends along the second conveying path. The first rotating spiral blade member is configured to have a smaller outer diameter than the outer diameter of the spiral blade of the second rotating spiral blade member. The developing device according to claim 1, wherein The first stirring and conveying means extends along the first conveying path and includes a first rotating spiral blade member including a central shaft portion and a spiral blade, and the second stirring and conveying means includes a second conveying path. And a second rotary spiral blade member including a central shaft portion and a spiral blade, the outer diameter of the central shaft portion of the first rotary spiral blade member being the center of the second rotary spiral blade member. The developing device according to claim 1, wherein the developing device is defined to be larger than an outer diameter of the shaft portion.

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