JP2003323047A - Developing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a developing device where toner existing on a toner guide member is shifted to a supply roller side neither too much nor too little and the toner exists so as to have uniform density in the longitudinal direction of the supply roller. <P>SOLUTION: The developing device is equipped with the toner guide member 133 having an inclined toner carrying part 137 extended in an oblique direction from the upper part of a toner storing part 101 toward the lower surface side of the supply roller 105, forming a toner reservoir part 139 with the peripheral surface of the roller 105 in between and guiding the toner to the reservoir part 139 on the front side of the reservoir part 139, and the size of toner introducing width J being the width of a part where the toner is shifted from the carrying part 137 to the reservoir part 139 is equal to the width L of the roller 105. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a copying machine or a printer, and more particularly to a developing device used in a tandem type image forming apparatus and an image forming apparatus using the same.

[0002]

2. Description of the Related Art Conventionally, a developing device used in an image forming apparatus such as a copying machine or a printer has a two-component developing method using a toner and a carrier as a developer, and a toner only without using a carrier. There is a one-component developing method using.
In the 1-component color developing method among the 1-component developing methods,
A developing device of each color is rotated intermittently in a rotary manner such as four-cycle rotary developing to contact the photoconductor to develop, or a tandem system in which the developing device is fixed and the photoconductor of each color is fixed. There are known ones for developing.

FIG. 8 shows an example of prior art of a one-component development type developing device (Japanese Patent Laid-Open No. 2001-5149).
7 publication). As shown in FIG. 8, the developing device 200 is
The blade member 209 fixed to the tip of the arm portion 205 of the agitator 203 has an agitator 203 that rotates in a direction in which the toner is supplied from below to the supply roller 201, and the toner 207 is almost as high as the supply roller 201. The toner 207 is supplied onto the toner guide member 211 so that the blade member 209 of the agitator 203 guides the toner 207.

Further, the toner 207 supplied onto the toner guide member 211 is carried on the peripheral surface of the supply roller 201, and this is transferred to the photoconductor 215 via the developing roller 213. Further, the regulation blade 217 is used as the developing roller 21.
By contacting the peripheral surface of No. 3, the excess toner is scraped off from the peripheral surface to the area 219 therebelow.

[0005]

In such a conventional developing device, the width of the toner guide member 211 is set regardless of the width of the supply roller 201. However, when the width of the toner guide member 211 is larger than the width of the supply roller 201, excess toner exists at both ends of the supply roller 201, and the excess toner causes printing at both ends of the paper. It may cause a printed matter with high density. Conversely, the toner guide member 21
When the width of 1 is smaller than the width of the supply roller 201,
Since toner cannot be supplied to the entire effective width of the supply roller 201, there is a problem that a printed matter having a low density may be generated at both ends of the paper in relation to the paper.

An object of the present invention is to allow the toner existing on the toner guide member to move to the supply roller side without excess or deficiency so that the toner can be present in a uniform density along the length direction of the supply roller. Another object of the present invention is to provide a developing device and an image forming apparatus including the same.

[0007]

In order to achieve the above object, the developing device according to the first aspect of the present invention functions as a toner cartridge and transfers toner to the photosensitive drum adjacent to the photosensitive drum in the image forming apparatus. A developing device capable of developing a latent image on a photosensitive drum with toner by doing so, the housing having a toner containing portion inside, a supply roller rotatable around a rotation shaft, and a peripheral surface of the supply roller. A developing roller having a peripheral surface adjacent to, rotating around a rotation shaft, a regulating blade that abuts on the peripheral surface of the developing roller to level the toner adhering to the peripheral surface, and charges the toner. It extends obliquely from above the toner accommodating portion toward the lower surface side of the supply roller, and forms a temporary storage portion for toner between the toner storage portion and the peripheral surface of the supply roller, and is provided on the upstream side of the temporary storage portion. And a means for conveying the toner in the toner containing portion onto the toner guide member, the toner guide member having an inclined toner conveying portion for guiding the toner to the temporary storage portion, and the toner from the conveying portion. The toner introduction width J, which is the width of the portion that moves to the temporary storage portion, is characterized by having the same dimension as the width L of the supply roller.

According to the present invention, the toner introduction width J, which is the width of the portion of the toner guide member that moves from the conveying portion to the temporary storage portion of the toner, has the same dimension as the width L of the supply roller. The toner that exists in the temporary storage portion in the width direction without excess or deficiency is also carried by the supply roller in the width direction without excess or deficiency, so that the toner can be uniformly carried in the width direction of the supply roller. It will be possible. Therefore, it is possible to realize printing that does not cause a density difference or print unevenness in the paper width direction of the paper. In the present invention, "the toner introduction width J is equal to the width L of the supply roller".
Is not limited to the case where both widths are exactly the same, and includes the width of the range in which the above-described action and effect are obtained.

According to a second aspect of the present invention, in the developing device according to the first aspect, the regulating blade is accommodated in the toner accommodating portion below a position where the regulating blade is in contact with the developing roller. The toner guide space is formed above the upper surface of the toner.

According to the present invention, since the toner guide space is formed below the position where the regulating blade is in contact with the developing roller and above the upper surface of the toner stored in the toner storage portion, The upper surface of the toner in the toner container is always located below the position where the regulating blade is in contact with the developing roller. Therefore, the circulation path through which the toner scraped off by the regulation blade is returned to the toner storage portion is obstructed, or the regulation blade scrapes off the excess toner from the developing roller and regulates the amount of toner conveyed to the developing area. It is possible to effectively prevent the adverse effect that the toner is blocked or the function of appropriately charging the toner is hindered.

Further, since the toner scraped off by the regulation blade can be returned directly to the inside of the toner containing portion without using a return roller or the like, stress applied to the toner is reduced and the life of the toner can be extended. You can also get the effect. Therefore, it is possible to reduce stains on the printed white background and changes in density due to toner fogging and a decrease in the amount of charge, and it is possible to maintain good image quality.

According to a third aspect of the present invention, in the developing device according to the first or second aspect, the conveying section is formed to be inclined at an angle equal to or greater than the repose angle of the toner and formed in a plane. It is characterized in that it is a flat transport section. According to the present invention, the toner naturally slides down along the flat transport portion at a uniform speed. Since the inclination is the same at any point in the flat transport unit, the toner progresses to the supply roller side in the same manner, so that a constant amount of toner can always be stably supplied to the supply roller.

According to a fourth aspect of the present invention, in the developing device according to any one of the first to third aspects, the sphericity of the toner is 0.95 or more, preferably 0.95. It is characterized by being ˜0.97.

Since the toner having the above sphericity has high fluidity,
The technical significance of making the toner introduction width J equal to the width L of the supply roller is great, and with this configuration, the toner can be uniformly conveyed as a whole on the toner guide member in the supply roller direction. Therefore, it is possible to obtain a printed matter without printing unevenness.

Further, according to a fifth aspect of the present invention, in the image device according to any one of the first to fourth aspects, the surface of the toner guide member in the conveying portion and the temporary toner storing portion is provided. The roughness is characterized by being less than the average particle size of the toner. According to the invention,
Since the toner does not stop due to the unevenness of the surface of the toner guide member, the toner does not stay on the toner guide member and is conveyed over the entire surface in the direction of the supply roller at a uniform speed. .

Further, according to a sixth aspect of the present invention, in the image apparatus according to any one of the first to fifth aspects, the supply roller is rotated from the end portion on the inlet side of the toner guide member. It is characterized in that a seal side wall is formed around the shaft so as to be formed linearly at right angles to the rotation shaft of the supply roller. According to the present invention, it is possible to prevent the toner from leaking laterally and being conveyed by the seal sidewall while the toner is being conveyed to the supply roller via the flat conveying unit.

According to a seventh aspect of the present invention, in the image device according to any one of the first to sixth aspects, at both ends of the supply roller, toner has an effective length of the supply roller. It is characterized in that it is sealed so as not to leak outside. According to the invention,
Since the toner carried on both ends of the supply roller can be prevented from falling outward due to, for example, vibrations, the entire effective length of the supply roller can be used, and even for relatively large paper, It is possible to realize printing without uneven printing at both ends.

Further, in the invention described in claim 8 of the present application, in the image device described in any one of claims 1 to 7, the width L of the supply roller is substantially the same as the width of the sheet. It is characterized by being. According to the present invention, all the toner carried on the supply roller is effectively used, and the toner on the supply roller is used to perform printing on the paper side without excess or deficiency, so that no waste toner is used and printing unevenness does not occur. Printing can be realized.

According to a ninth aspect of the present invention, in the developing device according to any one of the first to eighth aspects, at least a part of the developing device is located below the toner guide space. And a toner guide surface inclined at an angle equal to or greater than the repose angle of the toner so that the toner scraped off the peripheral surface of the developing roller by the regulation blade can be guided into the toner storage portion. To do.

According to the present invention, since the toner guide surface inclined at an angle of repose or more can guide the toner scraped off by the regulation blade into the toner containing portion, the stress applied to the toner is reduced. The life of the toner can be extended.

According to a tenth aspect of the present invention, in the developing device according to any one of the first to ninth aspects, the means for conveying the toner is provided in the toner accommodating portion. An arm member that rotates around the rotation shaft in a direction toward the toner transport unit, and extends from the tip of the arm member in a direction opposite to the rotation direction of the rotation shaft, and the tip side is in pressure contact with the inner peripheral surface of the toner storage unit And an agitator having an elastic force so as to convey the toner existing between the agitator fin and the inner peripheral surface of the toner containing portion onto the toner guide member. is there.

According to the present invention, since the means for conveying the toner comprises an agitator having an arm member that rotates around the rotation axis in the direction toward the toner conveying portion, the toner conveyed by the stirring fin is It is possible to smoothly transfer the toner to the toner guide member.

The invention described in claim 11 of the present application is an image forming apparatus including the developing device according to any one of claims 1 to 10. According to the present invention, good image quality can be maintained as an image forming apparatus such as a printer.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. Before describing the developing device of the present invention, a tandem type image forming apparatus to which the developing device is applicable will be described first. Figure 1
1 is a schematic cross-sectional view showing an overall configuration of an image forming apparatus 1 to which a developing device according to the present invention is applied. The image forming apparatus 1 is
The housing 3 is provided with a paper discharge tray 5 formed on the top of the housing 3, and a door body 7 that is provided on the front surface of the housing so as to be openable and closable.
An image forming unit 11, a blower fan 13, a transfer belt unit 15 and a paper feeding unit 17 are provided, and a paper transport unit 19 is provided inside the door 7.

The image forming unit 11 is provided with four image forming stations 21 in which four developing devices for accommodating toners of different colors can be set. The four image forming stations 21 are for developing devices of yellow, magenta, cyan and black, and these are distinguished by reference numerals 21Y, 21M, 21C and 21K in the drawing. Image forming stations 21Y, 21M, 21C
21K, a photosensitive drum 23, a corona charging unit 25 provided around the photosensitive drum 23, and the developing device 100 of the present invention are disposed.

The transfer belt unit 15 includes a drive roller 27 which is driven to rotate by a drive source (not shown) and a drive roller 2.
7, a driven roller 29 provided obliquely above 7 and a tension roller 31, an intermediate transfer belt 33 stretched between these rollers and driven to circulate in the counterclockwise direction X in FIG.
The cleaning unit 34 is in contact with the surface of the intermediate transfer belt 33. The driven roller 29, the tension roller 31, and the intermediate transfer belt 33 are arranged side by side so as to be inclined with respect to the drive roller 27, and when the intermediate transfer belt 33 is driven by this, the belt conveyance direction X is downward. The belt surface 35 is positioned on the lower side, and the belt surface 37 whose transport direction is directed upward is positioned on the upper side.

The photosensitive drum 23 is pressed against the belt surface 35 along an arched line and is rotationally driven in the direction shown by the arrow in FIG. By adjusting the position of the tension roller 31, the tension of the intermediate transfer belt 33, the curvature of the arch, and the like can be controlled.

The drive roller 27 also serves as a backup roller for the secondary transfer roller 39. The drive roller 27
On the peripheral surface of, for example, a thickness of about 3 mm, a volume resistivity of 10 ⁵
A rubber layer of Ω · cm or less is formed, and constitutes a conductive path of a secondary transfer bias supplied through the secondary transfer roller 39 by being grounded via a metal shaft. Further, the diameter of the driving roller 27 is smaller than the diameters of the driven roller 29 and the tension roller 31, so that the recording paper after the secondary transfer can be easily separated by the elastic force of the recording paper itself. The driven roller 29 also functions as a backup roller for the cleaning means 34.

The cleaning means 34 is provided on the belt surface 35 side facing downward in the conveying direction, and conveys the collected toner and a cleaning blade 41 for removing the toner remaining on the surface of the intermediate transfer belt 33 after the secondary transfer. And a toner transport path 42. The cleaning blade 41 is in contact with a position where the intermediate transfer belt 33 is wound around the driven roller 29. On the back surface of the intermediate transfer belt 33, the image forming stations 21Y, 21M, 2
The primary transfer member 43 comes into contact with the positions facing the photosensitive drums 1C and 21K, and a transfer bias is applied to the primary transfer member 43.

The exposure unit 9 is the image forming unit 11
Is provided in a space diagonally below, and a blower fan 13 is provided diagonally above. A paper feeding unit 17 is provided below the exposure unit 9. The exposure unit 9 has a scanner means 49, which is composed of a polygon mirror motor 45 and a polygon mirror 47, arranged vertically on the bottom. In addition, a single f-θ lens 51 and a reflecting mirror 53 are provided in the optical path B, and a plurality of folding paths are provided above the reflecting mirror 53 so that the scanning optical paths of the respective colors are non-parallel to the photosensitive drum 23 and are folded. A mirror 55 is provided.

In the exposure unit 9, the polygon mirror 47
Image signals corresponding to the respective colors are emitted by a laser beam that is modulated and formed based on a common data clock frequency, and pass through the f-θ lens 51, the reflection mirror 53, and the folding mirror 55, and the image forming stations 21Y and 21Y.
The M, 21C, and 21K photosensitive drums 23 are irradiated, and a latent image is formed. The optical path length from the polygon mirror 47 of the exposure unit 9 to the photosensitive drum 23 for each image forming unit 11 is configured to be substantially the same, so that the scanning width of the light beam scanned in each optical path is also approximately the same. Since they are the same, no special configuration is required for forming the image signal. Therefore, the laser light source can be modulated and formed based on a common data clock frequency, even though the laser light source is modulated corresponding to different color images by different image signals. It is possible to prevent a color shift caused by a relative difference in the scanning direction, and to configure a color image forming apparatus having a simple structure and inexpensive.

The blower fan 13 functions as a cooling means, which guides air in the direction of the arrow in FIG. 1 and releases the heat from the exposure unit 9 and other heat generating parts. As a result, the temperature rise of the polygon mirror motor 45 is suppressed, deterioration of image quality is prevented, and the polygon mirror motor 45 is prevented.
It is possible to prolong the life of the.

The paper feeding unit 17 is provided with a paper feeding cassette 57 in which recording media P are stacked, and a pickup roller 59 for feeding the recording media P one by one from the paper feeding cassette 57. The paper transport unit 19 includes a pair of gate rollers 61 that regulates the timing of feeding the recording medium P to the secondary transfer portion, a secondary transfer roller 39 that is pressed against the drive roller 27 and the intermediate transfer belt 33, and a fixing unit 63. And a pair of discharge rollers 65 and a double-sided printing conveyance path 67.

The fixing means 63 has a rotatable fixing roller pair 69 in which a heating element such as a halogen heater is built in at least one side, and at least one roller of the fixing roller pair 69 is urged toward the other side to urge the sheet material. And a pressing unit that presses the secondary image secondarily transferred onto the recording medium P. The secondary image secondarily transferred onto the recording medium is recorded at a predetermined temperature in a nip portion formed by the fixing roller pair 69. It is fixed on the medium.

The above is a schematic configuration of the tandem type image forming apparatus 1 to which the developing device 100 of the present invention can be applied. The developing device 100 of the present invention is set in each of the image forming stations 21Y, 21M, 21C and 21K. To use. It should be noted that in FIG. 1, the developing devices of the respective colors are denoted by reference numerals 100Y, 100M, 100C, and 100K, respectively, corresponding to the colors of the toners of the developing devices, as in the image forming stations. Since the configurations of these developing devices are basically the same, the configuration of a general developing device 100 will be described below with reference to FIG.

FIG. 2 is a sectional view of the developing device 100. The developing device 100 includes a toner container 10 having a substantially cylindrical shape.
1 is provided with the housing 103, and the housing 1
03 supply roller 105 and developing roller 107
Is provided. As shown in FIG. 1, when the developing device 100 is set in the image forming station, the developing roller 107 is adjacent to the photosensitive drum 23 with a slight gap (for example, 100 to 300 μm) between them, It has a function of developing the latent image formed on the photosensitive drum 23 by the toner supplied to the peripheral surface of the developing roller 107 while rotating and driving in the direction opposite to the rotating direction (see the arrow in the figure). Such developing action is performed by the developing roller 10
A developing bias power source (not shown) applies a developing bias in which an AC voltage is superimposed on a DC voltage to a developing bias power source 7, and an oscillating voltage is applied between the developing roller and the photosensitive drum to generate an electrostatic charge formed on the photosensitive drum 23. The developing roller 107 is provided on the latent image portion.
It is performed by supplying the toner from. Incidentally, it is also possible to bring the developing roller 107 into contact with the peripheral surface of the photosensitive drum 23 for developing.

The supply roller 105 has a surface formed of urethane sponge, and rotates in the same direction as the development roller 107 (counterclockwise direction in FIG. 2) with the peripheral surface of the supply roller 105 in contact with the development roller 107. It is possible. A voltage equal to the developing bias voltage applied to the developing roller 107 is also applied to the supply roller 105.

On the developing roller 107, the regulating blade 10
9 is constantly pressed by the action of the leaf spring member 111 and the elastic member 112 provided below it so as to be uniform over the longitudinal direction of the peripheral surface of the developing roller 107,
Excessive amount of toner adhered to the peripheral surface of the developing roller 107 is scraped off so that a predetermined amount of toner is removed.
It is designed to be carried on the peripheral surface of. The regulation blade 109 also has a function of appropriately charging the toner 113.

The toner scraped off naturally falls and is mixed with the toner 113 in the toner accommodating portion 101. This point will be described in detail later. The other end of the seal member 115, one end of which is fixed to the housing 103, is in pressure contact with the upper side of the peripheral surface of the developing roller 107, thereby preventing the toner 113 in the housing 103 from scattering to the outside. There is.

A rotary shaft 117 is provided in the toner containing portion 101.
An agitator 119 that rotates in the clockwise direction in FIG. The agitator 119 includes two arm members 121 extending in mutually opposite directions about the rotation shaft 117, and each arm member 121 is a toner storage unit 1.
The size is set to be slightly shorter than the diameter of the circle of 01 cross section. From the tip of each arm member 121, the agitator 11
The stirring fins 123 extend in the direction opposite to the rotating direction of 9. The stirring fin 123 is composed of a flexible sheet member, and its tip end side is in pressure contact with the inner peripheral surface of the cylindrical toner container 101 by the elastic force caused by the flexibility. With this configuration, when the agitator 119 rotates, the inner peripheral surface of the toner containing portion 101 and the stirring fin 1
It is possible to convey the toner 113 existing in the area 125 between the toner and toner 23 onto the toner guide member described later by scraping it up with the stirring fin 123.

The upper surface 114 of the toner 113 accommodated in the toner accommodating portion 101 is set at a position lower than the position 127 where the regulating blade 109 is in contact with the peripheral surface of the developing roller 107. If the amount of toner is so large that the regulation blade 109 is buried, the regulation blade 1
The toner scraped off by the toner 09 is present near the regulation blade, and as a result, the toner storage unit 101
The circulation path returned to the inside is obstructed, and the regulation blade 1
This is because the function of 09 for scraping off excess toner from the developing roller 107 to regulate the amount of toner conveyed to the developing area and the function of appropriately charging the toner are impaired.

In this embodiment, more specifically, the position of the upper surface 114 of the toner 113 accommodated in the toner accommodating portion 101 is below the lower end of the regulating blade 109 and elastic with the leaf spring member 111. Intersection 128 with member 112
The upper limit is the position of. Toner container 10
The position of the upper surface 114 of the toner 113 in 1 is the intersection point 1
If it goes above 28, there is a possibility that the movement of the leaf spring member 111 may be restricted, and there is a possibility that an appropriate regulation pressure may not be obtained, and as a result, "a certain amount of toner is transferred to the peripheral surface of the developing roller 107. There is a possibility that the “function of carrying the toner on” and the “function of appropriately charging the toner” may be hindered. But,
As described above, by setting the upper limit of the position of the upper surface 114 of the toner 113 to the position of the intersection point 128, it is possible to eliminate the risk of hindering the functions.

The portion 127 where the regulating blade 109 is in contact with the peripheral surface of the developing roller 107 and the toner containing portion 101.
Between the upper surface 114 of the toner 113 accommodated therein,
The upper surface of the toner 113 is inclined at an angle of repose or more of the toner 113.
A toner guide surface 129 that is inclined to the 14 side is formed as a part of the housing 103. The toner guide surface 129 is attached to the developing roller 1 by the regulating blade 109.
It has a function of guiding the toner 113 scraped off from the peripheral surface of 07 to the toner containing portion 101 side.

The developing roller 1 is controlled by the regulating blade 109.
The toner 113 scraped off from the peripheral surface of 07 is not necessarily guided to the toner containing portion 101 by the toner guide surface 129, and the scraped toner 113 directly drops into the toner containing portion 101. May be In this way, the regulation blade 109 causes the developing roller 10 to
7, a toner guide space portion 131 is formed below the portion 127 in contact with the peripheral surface of the No. 7 for guiding the toner 113 scraped off from the peripheral surface of the developing roller 107 by the regulating blade 109 to the toner storage unit 101. Has been done.

A toner guide member 133 is provided above the toner containing portion 101. Toner guide member 13
3 is provided at the end portion 134 on the side away from the supply roller 105, and the toner 1 conveyed by the stirring fin 123 is provided.
Sharply formed scraper 1 for scraping 13
35, a flat conveying section 137 whose upper surface side on the supply roller 105 side with respect to the scraper 135 is inclined at an angle of the repose angle of the toner 113 or more and is formed in a plane, and is formed on the downstream side of the flat conveying section 137. The curved portion 141 whose upper surface is curved so as to form a concave curved surface, and the contact portion 143 which is in contact with the peripheral surface of the supply roller 105 on the downstream side of the curved portion 141 with an appropriate linear pressure. And. The surface roughness of the toner guide member 133 including the flat transport portion 137, the curved portion 141, and the contact portion 143 is formed to be less than the toner average particle diameter.

Further, due to the existence of the contact portion 143,
Toner 113 attached to the lower surface of the supply roller 105
Can be prevented from falling due to gravity, and a decrease in image density due to a decrease in the amount of toner that can be supplied to the developing roller can be prevented. A temporary toner storage portion 139 having a wedge-shaped cross section is formed between the curved portion 141 and the peripheral surface of the supply roller 105.

In the toner guide member 133 having such a shape, the toner 113 conveyed by the stirring fin 123 is scraped off by the scraper 135, and then the toner 1
13 is gravity-dropped at a uniform speed along the widthwise direction of the flat conveying section 137 and at any point in the inclination direction, and is temporarily stored in the temporary storage section 139 of the toner. In the toner temporary storage portion 139 that narrows in a wedge shape,
As the toner 113 advances to the narrow region, the pressure contact force with respect to the peripheral surface of the supply roller 105 gradually increases, so that the toner 113 is pressed against the peripheral surface of the supply roller 105, and the toner 113 on the peripheral surface. Are easily supported.
When the toner 113 is pushed out beyond the contact portion 143, it falls in the toner guide space portion 131 and is guided directly or by the toner guide surface 129 to the toner storage portion 1.
Returned to 01.

In the embodiment shown in FIG. 2, the contact portion 143 is formed integrally with the toner guide member 133, but as shown in FIG. 3B, the contact portion 143 is a separate member. The contact sheet 149 may have a certain elasticity, and the contact sheet 149 may be in pressure contact with the peripheral surface of the supply roller 105.

Here, an example of dimensions and the like of each of the main members will be given. In the above embodiment, the supply roller 105 has an electric resistance of 10 ⁵ Ω · cm to 10 ⁶ Ω · cm, an Asker F hardness of 60 degrees to 70 degrees, and a standard cell diameter of 300 to 400.
A plurality of μm-sized cells are present, which is made of urethane foam with a thickness of 2 to 4 mm, and an elastic layer is formed on the outer peripheral portion,
A diameter of 15 to 18 mm and a length of 297 mm were used. Further, the gap between the supply roller 105 and the inner surface of the housing 103 at the upper portion is maintained at about 0.5 to 1.5 mm, and the gap between the upper portion of the temporary toner storage portion 139 and the inner surface of the housing 103, that is, the toner is introduced. The height of the portion to be filled was 6 mm.

The width of the agitator 119 is 330 mm,
The width of the scraper 135 of the toner guide member 133 is 30
0 mm, and the regulation blade 109 has a plate thickness of 0.15 mm
A conductive urethane rubber having a thickness of about 2 mm is attached to the tip of a phosphor bronze plate or a stainless plate. Further, the stirring fin 123 uses a PET film having a thickness of about 0.1 to 0.2 mm, the toner 113 is a negatively chargeable toner having an average particle size of 7 μm, and is a polymerized toner having a circularity of 0.95 to 0.97.
The one with good fluidity is used.

It should be noted that the examples of the dimensions, the circularity of the toner, and the like shown here are not intended to be limited thereto, and the present invention appropriately changes the dimensions and the like within the scope of the technical idea thereof. Of course, other embodiments are also included.

Here, the circularity of the toner will be described.
The one-component non-magnetic toner is obtained by a pulverization method and a polymerization method. The pulverized toner is a resin binder with a pigment, a release agent,
After uniformly mixing the charge control agent with a Henschel mixer,
It is made by melting and kneading with a twin-screw extruder, cooling, and then subjecting to a coarse pulverization-fine pulverization step, a classification treatment, and further adding a fluidity improver. The pulverized toner that is preferably used in the present invention may be spheroidized for the purpose of improving transfer efficiency. For that purpose, if a device capable of crushing into a relatively round sphere in the crushing process, for example, a turbo mill known as a mechanical crusher (manufactured by Kawasaki Heavy Industries, Ltd.) is used, the circularity can be up to 0.93, Further pulverized toner is a commercially available hot-air spheronizing device “Surfing System SFS-3
The circularity can be up to 1.00 by using "mold" (manufactured by Nippon Pneumatic Mfg. Co., Ltd.).

As a method for producing a toner by a polymerization method, there are a suspension polymerization method, an emulsion polymerization method and the like. In the suspension polymerization method, a polymerizable monomer, a color pigment, and a release agent are added as necessary, and a mixture containing a dye, a polymerization initiator, a crosslinking agent, a charge control agent, and other additives is dissolved or dispersed. The resulting monomer composition is added to a water phase containing a suspension stabilizer (water-soluble polymer, poorly water-soluble inorganic substance) with stirring, granulated, polymerized, and colored to a desired particle size. Polymerized toner particles can be formed.

Polymerization method In the emulsion polymerization method, the toner circularity can be adjusted by controlling the temperature and time in the aggregation process of the secondary particles, so that the circularity can be freely changed. It is 94 to 1.00. On the other hand, in the suspension polymerization method, since a spherical toner is possible, the circularity is 0.98 to 1.
It becomes the range of 00. Further, by heating and deforming the toner at the glass transition temperature Tg or higher in order to adjust the circularity, the circularity can be freely adjusted to 0.94 to 0.98. The average particle size and circularity of the toner particles and the like shown in this embodiment are FPIA manufactured by Sysmex Corporation.
It is the value measured at 2100.

Further, the work function ψ of the supply roller 105_SR
Is a temporary storage unit 1 for the toner that contacts the supply roller 105.
Work function ψa of 39th part and work function ψ of toner 113
between t ψt ≧ ψ_SR ψt ≧ ψa Are configured to have a relationship of.

The work function (ψ) is measured by a surface analyzer (AC-2, manufactured by Riken Keiki Co., Ltd.) with an irradiation light amount of 500 nW, and this is the energy required to extract electrons from the substance. means. The smaller the work function, the easier it is to emit electrons, and the larger the work function, the less likely it is to emit electrons. Therefore, when a substance having a low work function is brought into contact with a substance having a high work function, the substance having a low work function is positively charged and the substance having a high work function is negatively charged. The work function itself is the energy (e
It is quantified as V).

Next, the stirring fin 12 of the agitator 119.
The relationship between the width W of No. 3, the inlet width H of the scraper 135, and the width L of the supply roller 105 will be described. As shown in FIG. 4, the width W of the stirring fin 123 is larger than or equal to the inlet width H of the scraper 135. In a preferred embodiment, the scraper 13
The inlet width H at 5 is larger than the width L of the supply roller or equal to the width L of the supply roller. When this is expressed by an equation, the width W of the stirring fin W ≧ the inlet width H (≧ the width L of the supply roller) (Equation 1). In Expression 1, in the relationship between the inlet width H and the width L of the supply roller, the reason (≧ width L of the supply roller) in parentheses is that the relationship “width of stirring fin W ≧ inlet width H” is satisfied. If so, the relation of “inlet width H ≧ feed roller width L” does not necessarily have to be satisfied, but on the other hand, in the preferred embodiment, “inlet width H ≧ feed roller width L” is satisfied. It means that relationships can also be met.

The width W of the stirring fin 123 is equal to that of the scraper 1
As shown in FIG. 4, of the toner 113 placed over the entire width of the agitating fin 123, the inlet of the toner guide member 133 is larger than the inlet width H at 35 or equal to the inlet width H. Since only the toner 113 in the range corresponding to the width H is scraped off from the stirring fin 123, a certain amount of toner 113 always exists in the lengthwise direction of the inlet width H portion. Therefore, a uniform amount of the toner 113 is provided in the longitudinal direction of the supply roller 105.
Can be supplied on average, so that it is possible to realize printing in which the difference in density does not occur in the paper width direction of the paper to be printed.

Further, the width W of the stirring fin 123 is equal to the inlet width H.
By being greater than or equal to, the toner guide member 13
Since it is possible to reliably avoid the situation where the toner 113 is not supplied to the left and right ends of the entrance width H portion of No. 3, the printing that does not cause a difference in density in the paper width direction is guaranteed also in this respect.

Further, if the condition "inlet width H≥feed roller width L" is also satisfied while the condition "agitating fin width W≥inlet width H" is satisfied, then as described above, the toner guide member is obtained. Since there is always a constant amount of toner 113 in the entrance width H portion of 133, a uniform amount of toner 113 is also supplied to the supply roller 105 having a width dimension smaller than this, over the entire width thereof. Therefore, it is possible to more reliably perform printing that does not cause a difference in density in the paper width direction.

Next, the width of the portion where the toner is transferred from the flat transport section 137 to the temporary storage section 139, that is, the temporary storage section 13
The relationship between the toner introduction width J to the sheet 9 and the width L of the supply roller 105 will be described. FIGS. 5A and 5B are schematic diagrams showing the relationship between the toner introduction width J and the width L of the supply roller 105. In both of FIGS. 5A and 5B,
The positions of the toner introduction width J and the width L of the supply roller 105 are aligned and have the same length. In FIG. 5A, the entrance width H is set to be equal to the toner introduction width J, and in FIG. 5B, the entrance width H is set to be larger than the toner introduction width J.

As shown in FIGS. 5A and 5B, since the toner introduction width J is equal to the width L of the supply roller 105, the toner 1 temporarily stored in the temporary storage unit 139 is stored.
13 is the supply roller 105 as it is over the width direction.
It can be carried in parallel to the side and carried on the peripheral surface of the supply roller 105. Therefore, since the toner 113 stored in the temporary storage unit 139 is carried on the supply roller 105 in the width direction without excess or deficiency, a uniform amount of toner 113 can be carried in the width direction of the supply roller 105, It is possible to realize printing in which there is no difference in density in the paper width direction.

In FIG. 5A, the seal sidewall 1 is hung from the scraper 135 around the rotary shaft of the supply roller 105.
47 is formed linearly at right angles to the rotation axis of the supply roller 105. By forming such a seal side wall 147, the scraper 135 is moved to the flat conveyance unit 137.
It is possible to prevent the toner 113 from leaking laterally and being conveyed while the toner 113 is being conveyed to the supply roller 105 via the. Further, as shown in FIG. 5A, both end portions of the supply roller 105 are sealed by the seal side walls 147, which prevents the toner from leaking outside the effective length of the supply roller 105.

Further, in FIG. 5B, since the inlet width H is set to be larger than the toner introduction width J, the toner having a width larger than the toner introduction width J is indicated by the arrow in FIG. 5B. 113 (toner existing near both ends of the scraper 135) comes closer to the inside, but the temporary storage unit 1
Since the toner 113 is temporarily stored in 39, the toner amount does not actually increase only at the both ends of the introduction width J, and as in the embodiment of FIG. Printing that does not occur can be realized.

In the embodiment shown in FIGS. 5A and 5B, if the width L of the supply roller 105 is substantially the same as the paper width (not shown), all the toner carried on the supply roller 105 is effective. It is more preferable because the toner on the supply roller 105 is used for printing on the paper side without excess or deficiency.

Next, the shutter structure for preventing the toner 113 conveyed by the stirring fin 123 from being received on the toner guide member 133 will be described with reference to FIGS. 2, 6 and 7. 6 is a perspective view showing the periphery of the toner guide member 133 in the embodiment shown in FIG. 2, and FIG. 7 is an enlarged view showing the periphery of the toner guide member 133 showing various embodiments of the shutter structure.

As described above, the toner 113 on the toner guide member 133 naturally slides down on the toner guide member 133 and collects in the temporary toner storage portion 139, and when the supply roller 105 rotates, it is carried on the peripheral surface thereof. It will be consumed. However, when low duty printing is performed depending on the type of paper to be printed, the design to be printed, etc., the stirring fin 123
Since the toner is excessively supplied to the toner guide member 133, in this case, the toner supply to the toner guide member 133 by the stirring fin 123 must be stopped. For this purpose, a shutter structure described below is provided around the scraper 135 of the toner guide member 133.

That is, in the embodiment shown in FIG. 2, as shown in detail in FIGS. 6 and 7A, the toner guide member 133 is used.
15 above the end 134 of the
A shutter member 15 that can approach and separate as shown in FIG.
3 is provided. The shutter member 153 is constantly urged by the coil spring 157 in the direction away from the end portion 134, while the toner amount monitoring sensor 155 (see FIG. 2) facing the temporary toner storage portion 139,
When it is detected that the amount of the toner 113 stored in the toner temporary storage portion 139 exceeds a certain amount, the solenoid valve 159 (see FIG. 6) is activated to operate the shutter member 1.
53 is pressed against the end portion 134 of the toner guide member 133. Instead of providing the toner amount monitoring sensor 155, the shutter member 153 may contact the end portion 134 to temporarily stop the toner supply during low duty printing.

FIGS. 7B to 7D show another embodiment of the shutter member 153 for stopping the toner supply to the toner guide member 133. In the embodiment shown in FIG. 7B, the shutter member 153 can rotate about the rotation fulcrum 161.
In the middle, when the shutter member 153 is at the position shown by the solid line, it acts to stop the toner supply to the toner guide member 133, and when it is at the position shown by the phantom line, it becomes possible to supply the toner to the toner guide member 133. ing.

Further, in the embodiment shown in FIG. 7C, a rotation fulcrum 161 is formed on the downstream side of the end portion 134 of the toner guide member 133 in the toner conveying direction, and the tip end side of the rotation fulcrum 161 is formed. The portion of is functioning as the shutter member 153. That is, in FIG. 7C, when the shutter member 153 is at the position shown by the solid line, it acts so as to stop the toner supply to the toner guide member 133, and when it is at the position shown by the phantom line, the toner guide member 1 is shown.
It is possible to supply toner to 33. The rotation fulcrum 161 is substantially flush with the surface of the flat transport unit 137 so as not to hinder the smooth transport of the toner.

Further, in the embodiment shown in FIG. 7D, the stirring fin 123 can rotate around the rotary shaft 163.
There is provided a shutter member 153 that comes into contact with the upper surface side of the shutter and functions as a cam. In the present embodiment, FIG.
As shown by the solid line in (d), when the shutter member 153 acts to push the stirring fin 123 downward by the cam action, the stirring fin 123 is elastically deformed and separated from the scraper 135. The toner supply to the toner guide member 133 can be stopped. Further, when the shutter member 153 is rotating as shown by the phantom line, the stirring fin 123 causes the scraper 13 to rotate.
Since it comes into contact with the toner 5, the toner can be supplied to the toner guide member 133.

Next, the circulation of toner in the developing device according to the present embodiment will be described. Toner storage unit 101
The toner 113 contained in the toner is stored in the area 125 between the inner peripheral surface of the toner storage unit 101 and the stirring fin 123 by the rotating action of the agitator 119, and the toner 113 is scraped up by the stirring fin 123. The scraped toner 113 is scraped off by the scraper 135, slides down on the flat transport unit 137, and falls into the toner storage unit 139.
Leading to.

Toner 11 accumulated in the toner reservoir 139
3 is sequentially carried on the peripheral surface of the supply roller 105, then this toner moves to the developing roller 107 side, the excess toner is scraped off by the regulating blade 109, and the toner carried on the developing roller 107 is removed. The toner is charged by the regulation blade 109 and the toner develops the electrostatic latent image formed on the photosensitive drum 23.

The toner 113 scraped by the regulating blade 109 falls in the toner guide space 131 due to gravity and is directly returned to the toner accommodating portion 101, or slides down on the toner guide surface 129 and the toner accommodating portion. 1
Returned to 01.

[0075]

According to the present invention, the toner introduction width J, which is the width of the portion of the toner guide member that moves from the conveying portion to the toner temporary storage portion, has the same dimension as the width L of the supply roller. The toner existing in the temporary storage portion of the toner in the width direction without excess or deficiency is also carried by the supply roller in the width direction without any excess or deficiency, so that the toner is uniformly carried in the width direction of the supply roller. It becomes possible. Therefore, it is possible to realize printing that does not cause a density difference or print unevenness in the paper width direction of the paper.

[Brief description of drawings]

FIG. 1 is a side sectional view showing a tandem type image forming apparatus to which a developing device of the present invention can be applied.

FIG. 2 is a side sectional view of the developing device of the present invention.

3A is a side sectional view showing a state around a toner guide member of the developing device of FIG. 2, and FIG. 3B shows an embodiment in which a contact sheet is applied to a contact portion of the toner guide member. It is a sectional side view shown.

FIG. 4 is a perspective view showing a state around a stirring fin, a toner guide member, and a supply roller according to the present invention.

5A and 5B are schematic views showing different embodiments of the toner guide member according to the present invention.

FIG. 6 is a perspective view showing the periphery of a shutter member according to the present invention.

7A to 7D are schematic views showing different embodiments of a shutter member according to the present invention.

FIG. 8 is a side sectional view showing a conventional developing device.

[Explanation of symbols]

1 Image Forming Apparatus 11 Image Forming Unit 21 Image Forming Station 23 Photosensitive Drum 25 Corona Charging Means 100 Developing Device 101 Toner Housing 103 Housing 105 Supply Roller 107 Developing Roller 109 Restricting Blade 111 Leaf Spring Member 112 Elastic Member 113 Toner 114 Top of Toner 115 seal member 119 agitator 123 agitation fin 125 region 127 between inner peripheral surface of toner container and agitation fin 127 location where regulating blade abuts on peripheral surface of developing roller 129 toner guide surface 131 toner guide space 133 toner Guide member 134 End of toner guide member away from supply roller 135 Scraper 137 Flat transport unit 139 Toner temporary storage unit 141 Curved portion 143 Contact portion 147 Seal side wall 149 Contact sheet 153 Shutter portion 155 toner amount monitoring sensor 157 coil spring 159 solenoid valve 161 pivot point 163 rotation axis W inlet width L width of the supply roller in the width H toner storage stirring fins of the agitator

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G03G 15/08 505 G03G 9/08 9/08 15/08 507E 507L (72) Inventor Nobumasa Abe Suwa Nagano Prefecture 3-5 Yamato, Ichi, Seiko Epson Co., Ltd. (72) Inventor Masasho Sho 3-5, Yamato, Suwa, Nagano Seiko Epson Co., Ltd. F term (reference) 2H005 AA15 2H077 AA12 AA18 AA20 AB03 AB14 AC03 AC04 AD02 AD06 AD13 AD17 AD23 AE03 BA02 BA08 BA10 CA12 DA12 DA42 DB01 EA14 EA15 EA16 FA01 FA22 GA13

Claims (11)

[Claims] 1. A developing device that functions as a toner cartridge and that can develop a latent image on a photosensitive drum with toner by moving the toner to the photosensitive drum adjacent to the photosensitive drum in the image forming apparatus, A housing for forming a toner storage portion, a supply roller rotatable around a rotation shaft, a developing roller having a peripheral surface adjacent to the peripheral surface of the supply roller, and rotating around the rotation shaft, A regulating blade that abuts on the peripheral surface of the roller to evenly disperse the toner adhering to the peripheral surface and charges the toner, and extends obliquely from above the toner accommodating portion toward the lower surface of the supply roller, A temporary toner storage part is formed between the roller and the peripheral surface of the roller, and an inclined toner transport part for guiding the toner to the temporary storage part is provided on the upstream side of the temporary storage part. And a means for transporting the toner in the toner storage portion onto the toner guide member, and the toner introduction width J, which is the width of the portion that transitions from the transport portion to the temporary toner storage portion, is A developing device having a size equal to the width L of the roller. 2. The method according to claim 1, wherein the regulating blade is below a position in contact with the developing roller,
A developing device, comprising: a toner guide space portion formed above an upper surface of the toner contained in the toner containing portion. 3. The developing device according to claim 1, wherein the transport section is a flat transport section that is inclined at an angle equal to or greater than the repose angle of toner and is formed in a plane. 4. The developing device according to claim 1, wherein the sphericity of the toner is 0.95 or more, preferably 0.95 to 0.97. 5. The surface roughness of the toner guide member in the conveying section and the temporary toner storage section according to claim 1, wherein the surface roughness is less than the average particle diameter of the toner. Developing device. 6. The toner according to claim 1, wherein the toner guide member is hung from the inlet end of the toner guide member around the rotation shaft of the supply roller, and is perpendicular to the rotation shaft of the supply roller. Further, the developing device is characterized in that a linear seal sidewall is formed. 7. The toner supply device according to claim 1, wherein both ends of the supply roller are sealed so that toner does not leak outside the effective length of the supply roller. Development device. 8. The developing device according to claim 1, wherein the width L of the supply roller is substantially the same as the width of the sheet. 9. The toner according to claim 1, wherein at least a part of the toner is located below the toner guide space and is scraped off the peripheral surface of the developing roller by the regulation blade. And a toner guide surface that is inclined at an angle equal to or greater than the repose angle of the toner so that the toner can be guided into the toner storage unit. 10. The toner transporting means according to claim 1, wherein the toner transporting means is provided in the toner containing portion, and rotates in a direction around the rotation shaft toward the toner transporting portion. And a stirring fin that extends from the tip of the arm member in a direction opposite to the rotation direction of the rotating shaft and has an elastic force so that the tip side is in pressure contact with the inner peripheral surface of the toner containing portion. A developing device, which is an agitator that conveys the toner existing between the toner container and the inner peripheral surface of the toner containing portion onto the toner guide member. 11. The method according to any one of claims 1 to 10.
An image forming apparatus comprising the developing device according to the item.