JPS6333225Y2 - - Google Patents

Description

[Detailed explanation of the invention] Background of the invention (1) Field of the invention The invention relates to a developing device for an electrostatic copying machine, and in particular, the invention supplies a developer to a developing roller to form a magnetic brush, and the magnetic brush is used to expose the photosensitive material to light. The present invention relates to a developing device that performs development by rubbing a body.

(2) Description of prior art In conventional developing devices, the developer contained in the storage container aggregates and causes a so-called blocking phenomenon, which prevents the developer from flowing smoothly from the storage container to the developing roller. will no longer be supplied,
Development defects such as development spots and insufficient development sometimes occurred. In particular, when the developer is a one-component magnetic toner, the blocking phenomenon tends to occur because the developer has a small diameter of 5 to 30 microns. As a prior art technique for solving such technical problems, there is a technique in which a stirring means driven by the main motor of an electrostatic copying machine is provided in a storage container, but the structure is complicated.

The present invention aims to solve the above-mentioned technical problems, and to provide a developing device with a simple structure that prevents blocking of the developer in the developer container and can supply a constant amount of developer to the developing roller.

Structure of the invention The present invention supplies a magnetic developer to a developing roller 72 disposed close to the photoreceptor 3, and slides the surface of the photoreceptor 3 with a magnetic brush formed on the circumferential surface of the developing roller 72. In a developing device that performs development by rubbing, at least the bottom portion thereof is formed in a downwardly convex semicircular arc shape, and is provided with a supply port 89 that is opened to supply developer from above to the circumferential surface of the developing roller 72. A storage container 73 to be stored; a rotation shaft 92 rotatably supported at the center of the semicircular arc of the storage container 73; , an agitation supply member 93 that agitates the developer in the storage container 73 and brings it to the supply port 89; a ratchet wheel 94 fixed concentrically to the rotation shaft 92; and a pivot pin 95 parallel to the rotation shaft 92. a driving pin 100 that is integrally provided with an end of the developing roller 72 and protrudes at a position off the axis of the developing roller 72; one end of which is pivotally supported by the pivot pin 95; A longitudinal engagement portion 101 for engaging with the drive pin 100 is formed at the other end, thereby swinging about the pivot pin 95 as a fulcrum in response to the rotational movement of the developing roller 72. a swinging rod 96; and a pawl 98 provided in the middle of the swinging rod 96 to engage with the teeth of the ratchet wheel 94 and driving the ratchet wheel 94 in one rotation direction in response to the rocking movement of the rocking rod 96; , a biasing means 99 that biases the pawl 98 in a direction to engage the teeth of the ratchet wheel 94 , and a reverse rotation prevention member 10 that prevents the ratchet wheel 94 from rotating in the opposite direction.
5. A developing device for an electrostatic copying machine, characterized in that it includes:

DESCRIPTION OF PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a simplified vertical cross-sectional view of a transfer type electrostatic copying machine according to an embodiment of the present invention, viewed from the front side.
A photosensitive drum 4 having a photosensitive member 3 provided on the entire circumferential surface of the drum 2 is rotatably mounted substantially in the center of the body 1. Around the photosensitive drum 4, a charging corona discharger 6 for charging the photosensitive member 3 and a charging corona discharger 6 for visualizing the electrostatic latent image formed on the photosensitive member 3 are arranged sequentially along the direction of rotation shown by an arrow 5. A developing device 7 for forming a toner image, a transfer corona discharger 8 for transferring the toner image formed on the photoconductor 3 onto copy paper, and a cleaning device for cleaning the toner remaining on the photoconductor 3 after the transfer process. 9 is placed.

Above the photosensitive drum 4, an image of the document is transferred between the charging corona discharger 6 and the developing device 7.
an exposure device 10 for irradiating the area as indicated by the dashed arrow;
is provided. At the top of the machine 1, there is a document table 1 that places the document horizontally and moves back and forth like an arrow.
1 is provided. In the exposure apparatus 10, a light projecting means 12 for irradiating light onto the original via the original placing table 11 includes an exposure lamp, a reflector 14a, and a sub-reflector 14b. The light irradiated from the light projecting means 12 onto the original on the original mounting table 11 is irradiated onto the photoreceptor 3 through the single focus lens 15 to form an image of the original, and an electrostatic charge is generated on the photoreceptor 3. Form a latent image.

Copy sheets stacked and stored in a paper feed cassette 17 are fed from the paper feed cassette 17 by a paper feed roller 18 along a copy paper transport path 16 shown by a broken line. The copy paper passes through a pair of upper and lower guide plates 19 and 20 and is conveyed by a pair of feed conveyance rollers 21 and 22. The copy paper fed into the transfer area 25 via the pair of upper and lower guide plates 23, 24 is brought into close contact with the photosensitive drum 4 facing the transfer corona discharger 8. After the transfer process, one end of the copy paper in the width direction is separated by the separation roller 26 and the separation auxiliary roller 2.
7 and peeled off from the photosensitive drum 4,
After passing through the guide plate 28, a pair of heat fixing rollers 29, 3
0 to a heat fixing device 31 provided with 0. In this thermal fixing device 31, the toner image on the copy paper is fixed. After the fixing process, the copy paper is discharged onto a copy tray (not shown) by a pair of discharge rollers 32 and 33.

FIG. 2 is a front view showing the drive system seen from the back side of the copying machine. A sprocket wheel 36 is fixed to the output shaft 35 of the motor 34, and a first endless chain 37 is wound around the sprocket wheel 36. The chain 37 is wound around a sprocket wheel 38, a sprocket wheel 39 connected to the feed conveyance roller 22, and a sprocket wheel 40 connected to the paper feed roller 18 in order along the running direction indicated by the arrow. . A second endless chain 41 is wound around another sprocket wheel (not shown) that is integrally fixed to the output shaft 35 with the sprocket wheel 36. This chain 41
, sprocket wheels 42 and 43, and two sprocket wheels 44 and 4 for driving the original table 11 are arranged in order along the running direction indicated by the arrow.
5 and sprocket wheels 46, 47. A gear (not shown) that rotates in tandem with the sprocket wheel 43 is meshed with a gear 48 connected to the heat fixing roller 29. The sprocket wheel 44 is connected to a gear 49 via a clutch (not shown).
5 is connected to a gear 50 and a pulley 51 via a clutch (not shown). Gears 49 and 50 are meshed with each other. A wire 160, one end of which is connected to the right end of the original table 11 in FIG.
61 and wound around the pulley 51, and then wound around the pulley 16 again.
1 and is connected to the left end of the document table 11 in FIG. By switching a clutch (not shown), the pulley 51 is rotated in the forward and reverse directions, and the original table 11 is accordingly reciprocated in the direction of the arrow. Due to the action of the two clutches, when the original platen 11 is driven by the driving force from the sprocket wheel 44, the original platen 11 is moved at a relatively high speed, and the driving force from the sprocket wheel 45 is driven by the original platen 11. When the original table 11 is driven by force, the original table 11 is moved relatively slowly.

A gear 52 coaxial with the sprocket wheel 46 is connected to a gear 57 via gears 53, 54, 55, and 56. The gear 56 is fixed to a rotating shaft 58 of the cleaning device 9, and the gear 57 is fixed concentrically to the sleeve 120 of the cleaning device 9. A gear 60, which rotates integrally with the sprocket wheel 47, is connected to a gear 62 via a gear 61. This gear 62 is connected to a cylindrical member 128 of the cleaning device 9. Also gear 60
is connected via a gear 63 to a gear 64 that is integral with the separating roller 26 . Further, the gear 60 is connected to a gear 65 that is integral with the photosensitive drum 4, and the gear 65 is connected to a gear 69 via gears 66, 67, and 68. This gear 69 is connected to a developing sleeve 71 of the developing device 7.

FIG. 3 is an enlarged sectional view of the vicinity of the developing device 7 as seen from the front side. The developing device 7 includes a developing roller 72 arranged parallel to the axis of the photosensitive drum 4 and close to the photoconductor 3, a storage container 73 that stores monocomponent magnetic toner as a developer, and a storage container 73 that stores a single-component magnetic toner as a developer. An agitation supply means 74 for stirring the one-component magnetic toner and supplying the one-component magnetic toner to the developing roller 72; and an arbor for regulating the length of the magnetic brush formed on the circumferential surface of the developing roller 72. It includes a cutting member 75 and a blade member 76 for once separating the magnetic brush from the circumferential surface of the developing roller 72 and bringing it to the ear cutting member 75.

FIG. 4 is a simplified sectional view taken along the section line - in FIG. 3. The developing roller 72 has a permanent magnet 77 fixed concentrically within a hollow developing sleeve 71 made of a non-magnetic material. One end of the permanent magnet 77 passes through one end of the developing sleeve 71 via a bearing 82, and is attached to the front plate 7 of the frame 78 of the developing device 7.
It is fixed to a support member 81 fixed to 9. The other end of the developing sleeve 71 passes through a rear plate 80 of the frame 78 via a bearing 83, and a gear 69 is fixed thereto. The other end of the permanent magnet 77 is supported by the developing sleeve 71 via a bearing 84. The permanent magnet 77 has a plurality of magnetic poles magnetized at equal intervals in the circumferential direction, with adjacent magnetic poles having opposite polarities. The second mentioned above
As explained in the figure, the driving force is transmitted to the gear 69, which rotates the developing sleeve 71 in the direction of the arrow 85, so that the one-component magnetic toner supplied from the storage container 73 is developed. A magnetic brush is formed on the sleeve 71. At the development position 86, the circumferential surface of the photoreceptor 3 is rubbed by the magnetic brush, whereby the electrostatic latent image on the photoreceptor 3 is visualized.

FIG. 5 is a rear view of the developing device 7. The storage container 73 includes a semicircular arc portion 87 that is convex downward in a vertical plane and extends parallel to the developing roller 72 , and a circular arc portion 87 that extends parallel to the developing roller 72 with respect to the center line of the circular arc portion 87 .
It includes a conical part 88 that is connected to the upper part of the circular arc part 87 on the opposite side and is open upward, and is formed integrally with the frame body 78 . A supply port 89 for supplying one-component magnetic toner to the development roller 72 is formed in the arcuate portion 87 on the side opposite to the development position 86 with respect to the development roller 72 . This supply port 89
is formed above the developing roller 72 so that the one-component magnetic toner is supplied to the circumferential surface of the developing roller 72.

The agitation supply means 74 includes a rotation shaft 92 supported on the center line of the arc portion 87 by front and rear side plates 79, 80 via bearings 90, 91, and an agitation supply member integrally provided with the rotation shaft 92. 93 and rotating shaft 9
2, and one end is pivotally supported by a pivot pin 95 protruding from the rear plate 80.
and a swinging rod 96 whose other end is connected to the gear 69 and swings about the pin 95 as a fulcrum in response to the rotational movement of the gear 69; and a spring 99 that biases the pawl 98 and the ratchet wheel 94 toward the pawl 98 and the ratchet wheel 94 .

The agitation supply member 93 extends parallel to the inner wall 87a of the arcuate portion 87 between the front and rear side plates 79 and 80, and its both ends are bent at right angles and press-fitted onto the rotating shaft 92. A driving pin 100 is protruded from a position offset from the axis of the gear 69, and an elongated hole 101, which is a longitudinal engagement portion that engages with the pin 100, is formed at the other end of the swinging rod 96. . A spring 99 is provided surrounding the pin 97, and has one end hooked on the swinging rod 96 and the other end hooked on the claw 98. The spring force of spring 99 urges pawl 98 around pin 97 in the direction of arrow 102. A blocking piece 103 for restricting rotation of the claw 98 is provided on the swinging rod 96 in a protruding manner.

By one rotation of the gear 69, that is, one rotation of the developing sleeve 71, the swinging rod 96 is guided by the pin 100 engaged with the elongated hole 101, and the swinging rod 96 is guided by the pin 96.
5 as a fulcrum, it performs one reciprocating swing motion to the left and right in FIG. As a result, the pawl 98 connected to the swinging rod 96 is pressed, and the ratchet wheel 94 is pressed in the direction of the arrow 104 and angularly displaced. In accordance with the angular displacement of the ratchet wheel 94, the rotating shaft 92 is angularly displaced by the same amount of displacement,
The stirring supply member 93, which is integral with the rotation shaft 92, is angularly displaced. Therefore, the agitation supply member 93 is rotated around the rotation shaft 92 in accordance with the rotational movement of the developing sleeve 71, thereby agitating the one-component magnetic toner within the arcuate portion 87, and the rotation of the agitation supply member 93. One-component magnetic toner is brought to the supply port 89 by the longitudinal portion 93a. The one-component magnetic toner brought to the supply port 89 is supplied from the supply port 89 and brought to the peripheral surface of the developing sleeve 71 . As the agitation supply member 93 rotates in this way and the one-component magnetic toner in the arc portion 87 is agitated, blocking of the one-component magnetic toner in the storage container 73 is prevented, and A constant amount of toner is always brought to the peripheral surface of the developing sleeve 71 from the supply port 89 .

The rotation speed of the agitation supply member 93 is the same as that of the developing sleeve 7.
In this embodiment, the agitation supply member 93 is selected to rotate once while the developing sleeve 71 rotates 30 times. The number of teeth of the ratchet wheel 94 and the swinging distance of the pawl 98 may be selected.

A reverse rotation prevention member 105 for preventing the ratchet wheel 94 from reversing is fixed to the frame body 78, and the prevention member 105 prevents the ratchet wheel 94 from rotating on the downstream side in the rotation direction 104.
is in contact with the teeth of

Referring again to FIG. 3, on the upstream side of the developing position 86 along the rotational direction 85 of the developing sleeve 71, a panicle cutting member 75 close to the circumferential surface of the developing sleeve 71 is fixed to the frame 78. . This ear cutting member 75
As a result, the magnetic brush on the developing sleeve 71 is always regulated to a predetermined length and brought to the developing position 86, but on the upstream side immediately before the ear cutting member 75, the magnetic brush is cut by the ear cutting member 75. The one-component magnetic toner may remain and solidify, resulting in so-called blocking. This occurs because the one-component magnetic toner moving on the developing sleeve 71 is pressed against the ear cutting member 75, and the larger the pressing force is, in other words, the higher the rotational speed of the developing sleeve 71, the more this occurs. easy. When this blocking occurs, the magnetic brush on the developing sleeve 71 is blocked by the blocked one-component magnetic toner.
It is no longer brought to the development position 86, and development of that portion becomes impossible. Further, at the development position 86, the base portion of the magnetic brush does not contribute to development, remains on the circumferential surface of the development sleeve 71, and continues to rotate together with the development sleeve 71. As a result, the fluidity of the toner on the developing sleeve 71 decreases, and the way the spikes stand changes, resulting in a corresponding decrease in development efficiency.

Therefore, a blade member 76 is provided on the upstream side of the ear cutting member 75 along the rotation direction 85. This blade member 76 is inclined so as to move away from the developing sleeve 71 as it goes downstream in the rotational direction 85, and the base end 76a is fixed to the frame 78.
The free end portion 76b is in sliding contact with the developing sleeve 71 over its entire length. Here, in the permanent magnet 77, adjacent magnetic poles of opposite polarity are magnetized at a position corresponding to the ear cutting member 75 and a position where the free end portion 76b of the blade member 76 is in sliding contact. In this embodiment, as shown in FIG. 3, an N pole is magnetized at a position corresponding to the ear cutting member 75, and the blade member 7
The S pole is magnetized at the position corresponding to 6.

Referring to FIG. 6, which shows the plane of the blade member 76, a plurality of passage holes 106 are formed in the blade member 76 at intervals in its width direction (direction perpendicular to the paper surface of FIG. 3). These passage holes 106 have an N pole (or S pole) corresponding to the ear cutting member 75 and an S pole (or N pole) corresponding to the blade member 76.
It is formed approximately in the center between

It is assumed that the one-component magnetic toner attracted onto the developing sleeve 71 by the magnetic force of the permanent magnet 77 is brought to the position of the blade member 76 as the developing sleeve 71 rotates. Since the blade member 76 is in sliding contact with the developing sleeve 71, the one-component magnetic toner on the developing sleeve 71 is peeled off from the developing sleeve 71. Furthermore, since the blade member 76 is inclined in the rotation direction 85, the peeled one-component magnetic toner advances on the blade member 76 to the position of the passage hole 106. Since the passage hole 106 is formed approximately in the center between the N and S poles, the magnetic attraction force acting on the one-component magnetic toner in the passage hole 106 is directed perpendicularly to the lines of magnetic force, that is, in the radius of the developing sleeve 71. direction inward. Therefore, the toner passes through the passage hole 10.
6 to the developing sleeve 71 by the magnetic attraction force.
is easily fed radially inward.

In this way, by the action of the blade member 76,
Since the one-component magnetic toner once separates from the circumferential surface of the developing sleeve 71 and then falls through the passage hole 106 and is brought onto the developing sleeve 71, the one-component magnetic toner is always in a flowing state just before the ear cutting member 75. This prevents blocking from occurring. Moreover, since the one-component magnetic toner on the developing sleeve 71 is loosened by the blade member 76 every rotation of the developing sleeve 71, the way the ears of the magnetic brush stand at the developing position 86 is always constant, and the developing efficiency is improved. Improved.

FIG. 7 is a simplified sectional view taken along the section line - in FIG. 3. Referring to FIG. 7 and the above-mentioned FIG. 3, the developing device 7 is provided with a detection device 100 that detects the presence or absence of toner. This detection device 110 includes a detection member 111 that extends vertically between the supply port 89 of the storage container 73 and the developing roller 72 and is swingable in a plane perpendicular to the axis of the developing roller 72;
An engaging member 112 is fixed to the upper end of the detecting member 111, extends parallel to the axis of the developing roller 72, and is rotatably supported on both side plates 79, 80. Micro switch 1 as a switching means that changes the switching mode
13.

The detection member 111 has a through hole 11 formed in the frame 78 and for regulating the angular displacement range of the detection member 111.
4 and extends vertically through the engagement member 112.
is arranged above the through hole 114. One end of the engaging member 112 is bent at a right angle outside the side plate 79, and this bent portion 112a is engaged with the actuator 115 of the micro switch 113. The microswitch 113 is connected to toner replenishment instruction means such as a pilot lamp (not shown).

The developing roller 72 is supplied from the supply port 89 of the storage container 73.
Assume that one-component magnetic toner is supplied to The one-component magnetic toner is transferred to the developing sleeve 7 of the developing roller 72 by the attractive force of the permanent magnet 77.
1, the detection member 111 is pressed by the one-component magnetic toner and rotated in a direction approaching the developing roller 72, as shown by the imaginary line in FIG. At the first angular displacement position 116 of the detection member 111, the free end of the detection member 111 corresponds to approximately the center position of the N and S poles of the permanent magnet 77. By doing so, the detection member 111 can be
is more likely to be angularly displaced. As the detection member 111 is angularly displaced to the first angular displacement position 116, the engaging member 112 is angularly displaced, and the microswitch 113 is shut off accordingly. Therefore, in the first angular displacement position 116, the aforementioned pilot lamp is extinguished.

One-component magnetic toner is no longer supplied from the supply port 89 of the storage container 73, and the developing sleeve 7
When the toner runs out on the circumferential surface of the detection member 11, the pressing force exerted by the one-component magnetic toner decreases.
1 is the second angular displacement position 117 shown by the solid line in FIG.
Then, due to its own weight and the restoring force of the actuator 115 of the micro switch 113, it returns to rotation. A second angular displacement position 117 of this detection member 111
The micro switch 113 becomes conductive due to the angular displacement position of the engaging member 112 as the engagement member 112 returns to the rotation position.
The pilot lamp will light up accordingly. Thereby, it is displayed that the toner has run out in the storage container 73 and that the circumferential surface of the developing sleeve 71 has also run out of toner.

Note that the detection member 111 and the engagement member 112
It is preferable to make the weight as small as possible so that the toner can be angularly displaced by a slight pressing force of the toner.

FIG. 8 is an enlarged sectional view of the cleaning device 9 and its vicinity. The cleaning device 9 includes a magnetic brush cleaning means 122 having a permanent magnet 121 fixed in a rotatably driven sleeve 120 made of a hollow non-magnetic material, and a magnetic brush cleaning means 122 formed on the circumferential surface of the sleeve 120. a regulating member 123 for regulating the magnetic brush cleaning means 122;
a toner receiving container 12 that receives toner removed by
4, a feeding means 125 for forcibly feeding the remaining toner regulated by the regulating member 123 toward the toner receiving container 124, and an upstream side of the magnetic brush cleaning means 122 along the rotational direction 5 of the photosensitive drum 4. A hand brush roller 12 provided in
6 and a static elimination lamp 127 provided within the bristle brush roller 126.

FIG. 9 is a sectional view showing a part of the vicinity of the bristle brush roller 126 as seen from the section line - in FIG. 8. The bristle brush roller 126 is constructed by implanting a large number of bristle brushes 129 made of a flexible material such as acrylic resin on the outer peripheral surface of a cylindrical member 128 made of a translucent material such as glass. placed parallel to. Referring to FIG. 10, the bristle brush 129 has bristle flocked spirally on the outer peripheral surface of the cylindrical member 128 with a constant width d, and light transmitting portions 131 are formed between the bristle flock portions 130. The length of the bristle brush 129 is determined so that it touches the circumferential surface of the photosensitive drum 4 by a length δ from the free end (see FIG. 8). The length δ is suitably 1 to 5 mm.

Both ends of the cylindrical member 128 are fitted with sliding bearings 1 on both side plates 133 of the frame 132 of the cleaning device 9.
It is pivoted via 34. A static elimination lamp 127, which is longer than the cylindrical member 128, extends concentrically within the cylindrical member 128, and both ends of the static elimination lamp 127 are fixed by support means (not shown). Cylindrical member 1
The aforementioned gear 62 is fixed to one end of the sprocket wheel 28, and this gear 62 is connected via a gear 61 to a gear 60 coaxial with the sprocket wheel 47. The driving force transmitted from the sprocket wheel 47 drives the cylindrical member 128 to rotate in the direction of arrow 135 in FIG. The rotational speed of the bristle brush roller 126 is set so that the peripheral speed at the portion in sliding contact with the photosensitive drum 4 is 0 to 500 m/H higher than the peripheral speed of the photosensitive drum 4, preferably 100 to 300 m/H higher. chosen to be.
By selecting the rotational speed of the bristle brush roller 126 in this manner, the bristle brush roller 126 can slide against the photosensitive drum 4 and thereby damage the surface of the photoconductor 3 or damage the one-component magnetic toner on the photoconductor 3. Splashing is prevented.

Further, by rotating the bristle brush roller 126 at the above-mentioned circumferential speed difference, the position of the one-component magnetic toner remaining on the photoreceptor 3 is adjusted to the position of the bristle brush roller 126.
It is shifted in the circumferential direction by . Therefore, the light from the static eliminating lamp 127 is transmitted through the light transmitting portion 131 to the photoreceptor 3.
When the surface is irradiated, the light is irradiated onto the portion of the photoreceptor 3 where the one-component magnetic toner is displaced, and the charge is removed. This causes the bristle brush roller 12 to move along the rotational direction 5 of the photosensitive drum 4.
Magnetic brush cleaning means 1 on the downstream side of 6
22 is effectively cleaned.

By implanting flexible and conductive thin carbon fibers on the outer peripheral surface of the cylindrical member 128, frictional charging due to sliding contact between the bristle brush 129 and the photoreceptor 3 can be prevented. Further, the cylindrical member 128 may be made of a material that blocks light having wavelengths that have an adverse effect on the photoreceptor 3. In this case, the cylindrical member 128 can also serve as a filter for the static elimination lamp 127.

In this embodiment, the bristle brush 129 is attached to the cylindrical member 1.
28 is spirally implanted, so the light transmitting part 131
By appropriately determining the interval between the bristle brush rollers 126, the rotational speed of the bristle brush roller 126, and the contact length δ of the bristle brush roller 126 with respect to the photoreceptor 3, the amount of light irradiated onto the photoreceptor 3 by the static elimination lamp 127 can be appropriately determined. can.

FIG. 11 is a simplified cross-sectional view taken along section line XI--XI in FIG. 8. The magnetic brush cleaning means 122 is arranged close to the photoreceptor 3 parallel to the axis of the photoreceptor drum 4 . One end of the permanent magnet 121 supports one end of the sleeve 120 in a bearing 140.
The support member 141 is fixed to the side plate 133. The other end of the sleeve 120 passes through the side plate 133 via a bearing 142, and a gear 57 is fixed thereto. The other end of the permanent magnet 121 is supported by the sleeve 120 via a bearing 143. The permanent magnet 121 has a plurality of magnetic poles magnetized at equal intervals in the circumferential direction, with adjacent magnetic poles having opposite polarities. As explained in FIG. 2 above, power is transmitted to the gear 57, thereby causing the sleeve 1 to
20 is rotated in the direction of arrow 144 (see FIG. 8). Therefore, a magnetic brush having a certain length is formed by the regulating member 123 and is in sliding contact with the photosensitive drum 4 . As a result, the one-component magnetic toner remaining on the photoreceptor 3 is transferred to the permanent magnet 121.
It is attracted to the sleeve 120 by the magnetic attraction force and removed from the photoreceptor 3.

As explained in FIGS. 9 and 10 above, the residual toner on the photoreceptor 3 is removed by the bristle brush roller 1.
26 on the circumferential surface of the photoconductor 3, and the light from the charge eliminating lamp 127 is irradiated through the light transmitting portion 131, so that the entire circumferential surface of the photoconductor 3 is neutralized. Therefore, in the magnetic brush cleaning means 122, the toner on the photoreceptor 3 is easily attracted to the sleeve 120, and the cleaning efficiency of the magnetic brush cleaning means 122 is improved.

Referring again to FIG. 8, on the opposite side of the photosensitive drum 4 with respect to the magnetic brush cleaning means 122, a regulating member 123 is fixed to the frame 132 close to the circumferential surface of the sleeve 120. The length of the magnetic brush on the sleeve 120 is regulated by the regulating member 123, and in order to send the regulated and surplus toner to the toner receiving container 124,
Infeed means 125 are provided. The magnetic brush cleaning means 122 is located on the opposite side of the photosensitive drum 4 with respect to the magnetic brush cleaning means 122 .
A toner receiving container 124 that is open upward is provided below, and a passage 145 for feeding toner is formed between the magnetic brush cleaning means 122 and the toner receiving container 124.
The feeding means 125 is provided upstream of the regulating member 123 along the rotational direction 144 of the sleeve 120 at the opening 145a of the passage 145 on the magnetic brush cleaning means 122 side. This feeding means 125 has bearings 1 on both side plates 133.
A toner conveying member 148 made of a non-magnetic material is integrally provided with a rotating shaft 58 supported via a rotary shaft 47. A gear 56 is fixed to the rotating shaft 58, and the driving force transmitted to the gear 56 causes
The rotation shaft 58 is rotated in the direction of arrow 149 (see FIG. 8). The toner conveying member 148 is connected to the rotating shaft 58
, and both ends thereof are press-fitted and fixed at right angles to the rotating shaft 58. Rotation direction 149 of rotation shaft 58
is selected to be in the opposite direction to the rotational direction of the sleeve 120, so that the one-component magnetic toner remaining after being regulated by the regulating member 123 is conveyed by the toner conveying member 148 to the passage 145. It will definitely be brought within. The one-component magnetic toner brought into the passage 145 falls under its own weight inside the passage 145 and is brought into the toner receiving container 124 .

Referring to FIG. 8, the toner receiving container 124 is loaded on a microswitch 150 as a switching means, and this microswitch 150 causes the one-component magnetic toner accumulated in the toner receiving container 124 to be predetermined. It is determined that conduction occurs when the weight is reached. This microswitch 150 is connected to a toner recovery instruction means (not shown), such as a pilot lamp, and the pilot lamp is turned on when the monocomponent magnetic toner in the toner receiving container 124 reaches a predetermined weight. Therefore, it is possible to easily detect that the toner receiving container 124 is filled with one-component magnetic toner.

FIG. 12 is a sectional view of a developing device according to another embodiment of the present invention, which replaces the developing device 7 of the embodiment shown in FIGS. 1 to 11. In this embodiment, the permanent magnet 77 is magnetized with a pair of magnetic poles having the same polarity (S poles in this embodiment) close to each other, corresponding to the sliding contact position of the blade member 76 to the developing sleeve 71. .
According to the embodiment of the present inventor, remarkable effects were obtained by arranging magnetic poles on the circumferential surface of the permanent magnet 77 at intervals of 2 to 6 mm. Further, at a position corresponding to the ear cutting member 75, a magnetic pole (in this embodiment, N pole) adjacent to the two magnetic poles (in this embodiment, S pole) and opposite in polarity thereto is magnetized. The other parts of the developing device are constructed in the same manner as shown in FIG. 3 described above. In this way, by magnetizing a pair of magnetic poles of the same polarity at the sliding contact position of the blade member 76, the adsorption force of the one-component magnetic toner to the developing sleeve 71 at the sliding contact position of the blade member 76 is increased. become weak. Furthermore, since the lines of magnetic force from these magnetic poles of the same polarity are in the radial direction of the developing sleeve 71, a magnetic attraction force acts on the one-component magnetic toner in the tangential direction of the developing sleeve 71. Therefore, the one-component magnetic toner on the developing sleeve 71 is transferred to the developing sleeve 7 in front of the sliding contact position of the blade member 76.
1, jumps over the sliding contact position, moves to the blade member 76, and reaches the passage hole 106. Therefore, there is no need for the blade member 76 to strongly contact the sleeve 71, and it is possible to prevent the blade member 76 from blocking the toner.

FIG. 13 is an enlarged sectional view of a developing device according to another embodiment of the present invention, and parts corresponding to those in FIG. 3 are given the same reference numerals. In this embodiment, the permanent magnet 77 has a pair of magnetic poles having the same polarity (N pole in this embodiment) within the range from the development position 86 to the blade member 76 along the rotational direction 85 of the development sleeve 71. magnetized in close proximity. These magnetic poles are, for example, 2 to 6 on the circumferential surface of the permanent magnet 77.
spaced at mm intervals. The other parts are constructed in the same manner as in FIG. 3. With this configuration, the magnetic brush formed on the surface of the developing sleeve 71 does not contribute to development, and the developing position 86
The one-component magnetic toner that has rotated together with the developing sleeve 71 is temporarily displaced when it passes through a position where the magnetic poles of the same polarity are arranged close to each other. This is the N pole and S pole between the development position 86 and the position where the same magnetic pole is arranged.
This is because the regular changes in the chain structure of the magnetic brush due to the alternating arrangement of poles are transformed into irregular changes. Therefore, since the one-component magnetic toner is conveyed to the position of the blade member 76 in a state where the magnetization effect is weakened, the blade member 76
6 makes it easy for the toner to peel off from the circumferential surface of the developing sleeve 71.

The position where a pair of adjacent magnetic poles of the same polarity are magnetized is not limited to one location as shown in FIG. 13, but is within the range from the development position 86 to the blade member 76 along the rotational direction 85. It may be placed in multiple locations.

FIG. 14 is a plan view of a bristle brush roller 151 according to another embodiment of the present invention, which replaces the bristle brush roller 126 of the embodiment shown in FIGS. 1 to 11 described above. The bristle brush roller 151 may be formed by planting bristle brushes 129 in a grid pattern on the circumferential surface of the cylindrical member 128.

FIG. 15 is a sectional view of another embodiment of the present invention. The toner receiving container 124 is loaded on the frame 132 via the spring 152, and the spring 152 is compressed by the weight of the one-component magnetic toner accumulated in the toner receiving container 124, so that the one-component magnetic toner is pre-loaded. Micro switch 15 when the set value is reached.
0 may be made conductive. In this way, the detected weight can be adjusted by adjusting the spring force of the spring 152.

As described above, according to the present invention, with a relatively simple structure, it is possible to prevent blocking by stirring the developer in the storage container, and also to mix the developer in the storage container almost quantitatively and in almost no amount. We can supply it without any surplus.

In particular, in the present invention, one end of the swinging rod 96 is pivotally supported by the pivot pin 95, and a longitudinal engaging portion 101 is formed at the other end, and this longitudinal engaging portion 101 is It engages with a driving pin 100 that is integrally provided with the end of the developing roller 72 and protrudes from a position off the axis of the developing roller 72 . Therefore, it becomes possible to reliably swing the swinging rod 96 by the rotational movement of the developing roller 72. Therefore, the stirring supply member 93 can be reliably rotated by the action of the ratchet wheel 94 and the pawl 98.

Furthermore, according to the present invention, the pawl 98 is connected to the spring 9
Since the pawl 98 is spring-biased in the direction of engaging the teeth of the ratchet wheel 94 by the pawl 98, the pawl 98 can reliably engage the teeth of the ratchet wheel 94. Therefore, as the swinging rod 96 swings, the claw 98 can reliably angularly displace the ratchet wheel 94. This also ensures that the agitation supply member 93 can be driven reliably.

In this manner, the present invention makes it possible to reliably stir the developer in the storage container, to ensure prevention of blocking, and to reliably supply a constant amount of the developer.

Further, in the present invention, developer is replenished according to the rotation of the developing roller 72. Therefore, developer replenishment is achieved only during development, and more developer than necessary is not replenished.

Furthermore, according to the present invention, the swinging rod 96 swings about the pivot pin 95 in response to the rotation of the developing roller 72. The claw 98 provided on the swinging rod 96 also swings, and the claw wheel 9 moves in accordance with the movement of the claw 98.
4 rotates counterclockwise in FIG. 5, and the agitation supply member 93 rotates. Displacement of the ratchet wheel 94 is regulated by a reverse rotation prevention member 105. Therefore, it is possible to replenish toner in an accurate amount more reliably.

[Brief explanation of the drawing]

FIG. 1 is a simplified vertical cross-sectional view of an electrostatic copying machine according to an embodiment of the present invention as seen from the front side, FIG. 2 is a front view showing the drive system of multiple machines as seen from the back side, The figure is a simplified enlarged sectional view of the vicinity of the developing device 7 in FIG. 1 seen from the front side, FIG. 4 is a simplified sectional view taken from the cutting plane line - in FIG. 3, and FIG. 5 is a simplified sectional view of the developing device 7 is a rear view of the blade member 76, FIG. 6 is a plan view of the blade member 76, FIG. 7 is a simplified sectional view taken along the cutting plane line - of FIG. 3, and FIG. 9 is a sectional view showing a part of the vicinity of the bristle brush roller 126 seen from the cutting plane line - in FIG. 8, FIG. 10 is a plan view of the bristle brush roller 126, and FIG. Cut plane line in diagram
A simplified sectional view taken from XI-XI, FIGS. 12 and 13 are sectional views showing a developing device according to another embodiment of the present invention, and FIG. 14 is a bristle brush according to another embodiment of the present invention. A plan view of the roller 151 and FIG. 15 are cross-sectional views of another embodiment of the present invention. 3... Photoreceptor, 7... Developing device, 9... Cleaning device, 58, 92... Rotating shaft, 71... Developing sleeve, 73... Storage container, 74... Stirring supply means, 75... Corn cutting Member, 76... Blade member, 77, 121... Permanent magnet, 86... Development position, 89... Supply port, 93... Stirring supply member, 9
4...Rawl wheel, 96...Swinging rod, 98...Claw, 11
3,150... Micro switch, 116... First angular displacement position, 117... Second angular displacement position, 12
0... Sleeve, 122... Magnetic brush cleaning means, 123... Regulating member, 124... Toner receiving container, 125... Feeding means, 126,
151... Hair brush roller, 127... Static elimination lamp, 128... Cylindrical member, 129... Hair brush,
148...Toner conveying member.

Claims (1)

[Claims for Utility Model Registration] Developing roller 72 disposed close to photoreceptor 3
In a developing device that supplies a magnetic developer to the developing roller 72 and rubs the surface of the photoreceptor 3 with a magnetic brush formed on the circumferential surface of the developing roller 72, the developing device develops the image. a storage container 73 that stores the developer and is provided with a supply port 89 that is formed on the peripheral surface of the developing roller 72 to supply developer from above; and a storage container 73 that is rotatable at the center position of the semicircular arc of the storage container 73. a rotating shaft 92 that is pivotally supported by the rotating shaft 92; and a rotating shaft 92 that extends radially outward from the rotating shaft 92 and is close to the bottom inner surface of the storage container 73 to agitate the developer in the storage container 73 and supply the agitation to the supply port 89. A member 93, a ratchet wheel 94 fixed concentrically to the rotating shaft 92, a pivot pin 95 parallel to the rotating shaft 92, integrally with the end of the developing roller 72 and extending from the axis of the developing roller 72. a driving pin 100 protruding from a disengaged position, one end of which is pivotally supported by the pivot pin 95, and the other end of which is provided with a longitudinal engagement member for engaging with the driving pin 100; A swinging rod 96 that swings about the pivot pin 95 as a fulcrum in response to the rotational movement of the developing roller 72 and a swinging rod that engages with the teeth of the ratchet wheel 94 are formed. a pawl 98 provided in the middle of the ratchet 96 for driving the ratchet wheel 94 in one rotation direction in response to the rocking movement of the rocking rod 96; A biasing means 99 and a reverse rotation prevention member 10 that prevents reverse rotation of the ratchet wheel 94
5. A developing device for an electrostatic copying machine, comprising: