JPS63138380A - Image forming machine - Google Patents

Abstract

PURPOSE:To minimize the amount of toner to be charged by constituting a process unit mounted detachably on a support structure so that its life comes to the end substantially when a prescribed amount of charged fresh toner and toner which is used once, removed from conveyed into a toner storage chamber through the operation of a toner conveying means are consumed. CONSTITUTION:The process unit 16 has a unit frame, whose supported rail parts 24 and 26 are engaged with the support rails of an upper support frame body 6 to slide the unit frame 22 at right angles to the paper surface, so that the process unit 16 is mounted on and demounted from the upper support frame body 16. In this case, the process unit 16 comes to the end of its life substantially when a prescribed amount of charged fresh toner and toner which is removed from the surface of the photosensitive body and conveyed into the toner storage chamber through the operation of the toner conveying means are consumed.

Description

[Detailed description of the invention] Technical fields> TECHNICAL FIELD This invention relates to image producing machines such as electrostatic copying machines.

BACKGROUND ART As is well known to those skilled in the art, electrostatic copying machines or electrostatic printers of the type that form an electrostatic latent image on an electrostatographic photoreceptor and then develop such electrostatic latent image into a toner image Image generating machines such as the machine are in widespread use. An electrostatic copying machine, which is an example of an image generating machine, generally includes an electrostatic photoreceptor, an electrostatic latent image forming means for forming an electrostatic latent image on the surface of the photoreceptor, and a device for developing the electrostatic latent image. The image forming apparatus is equipped with a developing device for removing toner remaining on the surface of the photoreceptor after transfer, and a cleaning device for removing toner remaining on the surface of the photoreceptor after transfer.

The developing device includes a toner storage chamber that accommodates toner, and application means for applying toner to the electrostatic latent image, and the cleaning device includes toner removal means that acts on the surface of the photoreceptor to remove residual toner. and a toner collection chamber for collecting toner removed from the photoreceptor surface.

In such electrostatic copying machines, especially small so-called personal type ones, an electrostatic photoreceptor and a developing device (and a cleaning device) constitute a process unit that is detachably attached to the support structure of the electrostatic copying machine. However, when the photoreceptor reaches the end of its lifespan, there is a tendency to replace the entire process unit with a new one.

In other words, the amount of toner filled in the toner storage chamber of the developing device (and the amount collected in the toner collection chamber of the cleaning device) substantially corresponds to the life of the photoreceptor, and the photoreceptor has reached its lifespan. When the copying process is performed up to this point, the toner in the toner storage chamber is substantially discharged and consumed (furthermore, the toner removed from the surface of the photoreceptor substantially fills the toner collection chamber), and therefore the predetermined number of copies is When copying is performed, the entire process unit substantially reaches the end of its life, and at the end of its life it must be replaced with a new one.

However, in such an electrostatic copying machine, toner is used only once for the developing action, and therefore,
Requires a relatively large amount of relatively expensive toner, and in connection with this requires a larger toner storage chamber;
It is also necessary to enlarge the toner collection chamber.

On the other hand, in order to eliminate these inconveniences and use toner effectively, a toner transport means is provided in connection with the cleaning device and the developing device, and the toner is collected into the toner collection chamber of the cleaning device by the action of the toner transport means. There has also been proposed a configuration in which the toner is transferred to a toner storage chamber of a developing device and the toner is reused.

But 1. In such a configuration, if the toner is reused many times, generally more than twice, the image quality deteriorates significantly and it becomes difficult to obtain good copies.

<Object of the Invention> The present invention has been made in view of the above facts, and its main purpose is to provide an image generating machine that can avoid significant deterioration of image quality and substantially minimize the amount of toner filled. The goal is to provide the following.

<Summary of the Invention> According to the present invention, there is provided an electrostatographic photoreceptor, an electrostatic latent image forming means for forming an electrostatic latent image on the surface of the photoreceptor, and an electrostatic latent image forming means for forming an electrostatic latent image on the surface of the photoreceptor. The developing device includes a developing device that develops the latent image into a toner image, and a cleaning device that removes residual toner remaining on the surface of the photoreceptor after the toner image is transferred, and the developing device includes a toner storage chamber that stores toner; an application means for applying toner to the electrostatic latent image formed on the surface of the photoreceptor; the cleaning device includes a toner removal means for removing residual toner remaining on the surface of the photoreceptor; a toner collection chamber for collecting the toner removed by the action of the means, and a toner transporting chamber for transporting the toner collected in the toner collection chamber to the toner storage chamber in relation to the cleaning device and the developing device. in an image producing apparatus, wherein: at least the electrostatographic photoreceptor and the development device constitute a process unit removably mounted to a support structure; An image generator is provided that is configured to remove toner and transport the toner from the photoreceptor surface.

<Preferred specific examples of the invention> A more detailed explanation will be given below with reference to the accompanying drawings.

FIG. 1 illustrates a specific example of an electrostatic copying machine as an example of an image generating machine constructed in accordance with the present invention. In FIG. 1, the illustrated copying machine has a generally rectangular parallelepiped-shaped housing designated as a whole by numeral 2. As shown in FIG. In a specific example, the housing 2 is composed of a so-called shell-type support structure consisting of a lower support frame 4 and an upper support frame 6. The lower left end portion of the upper support frame 6 is rotatably connected to the lower support frame 4 via a shaft 8, and can pivot between a closed position shown by a solid line and an open position shown by a two-dot chain line. can be done.

A document f2 loading stage 10 is mounted on the upper surface of the housing 2, that is, on the upper surface of the upper support frame 6, so as to be able to reciprocate in the left-right direction. The document placement means 10 includes a transparent plate 12 on which a document to be copied is placed, and a document cover 14 that can be opened and closed to cover the transparent plate 12 and the document placed thereon. Contains.

A so-called process unit, which is located approximately at the center of the housing 2 and is generally designated by numeral 16, is removably attached to the upper support frame 6. More specifically, a pair of support rails 18 and 20 are fixed to the upper support frame 6, spaced apart from each other in the left-right direction and extending in a direction perpendicular to the paper surface. On the other hand, the process unit 16 is mounted on a unit frame 22.
Supported rail portions 24 and 26 are formed on both left and right sides of this unit frame 22, extending in a direction perpendicular to the plane of the drawing. Supported rail portions 24 and 2 of unit frame 22
, 6 are engaged with the support rails 18 and 20 of the upper support frame 6, respectively, and the unit frame 22 is slid in a direction perpendicular to the plane of the paper, thereby attaching and detaching the process unit 16 to the upper support frame 6. . A rotating drum 28 is rotatably mounted approximately at the center of the unit frame 22. A suitable electrostatic photoreceptor is disposed on the circumferential surface of the rotating drum 280. The unit frame 22 further includes an arrow 3
A charging corona discharger 32 and a developing device, generally designated by numeral 34, are disposed around the rotating drum 28 which is rotationally driven in the direction indicated by 0.

The upper support frame 6 is further provided with an optical means 36 for irradiating the original and projecting light reflected from the original onto the irradiating body. The illustrated optical means 36 is the document irradiation lamp 3
8, a reflection plate 40 and an optical system 42. The optical system 42 includes a large number of elongated optical elements (
For example, the rondo-shaped lens sold by Nippon Sheet Glass Co., Ltd. under the product name "Selfoc Micro Lens")
It consists of The light from the irradiation lamp 38 passes through the transparent plate 12 and irradiates the document placed thereon, as shown by the dashed line, and the reflected light from the document is formed on the optical system 42 and the upper wall 44 of the unit frame 22. The light is projected onto the circumferential surface of the rotating drum 28 in the exposure area 48 through the exposed exposure aperture 46 . In a specific example, as will be easily understood from the description below, the charging corona discharger 32 and the optical means 36 serve as an electrostatic latent image forming means for forming an electrostatic latent image on the surface of the photoreceptor of the rotating drum 28. The electrostatic latent image formed by the action of the electrostatic latent image forming means is developed into a toner image by a developing device. In addition, in the specific example, a part of the light from the irradiation lamp 38 is also formed in the opening 50 formed in the lower surface of the reflection plate 40 and the upper wall 44 of the unit frame 22, as similarly shown by the dashed line. The light is projected onto the circumferential surface of the rotating drum 28 in the static eliminating area 54 through the static eliminating light aperture 52 . A cleaning device 56 is also arranged around the rotating drum 28. The developing device 34 and cleaning device 56 will be described in detail later.

Approximately at the center of the lower support frame 4, there is a transfer corona discharger 60 facing the circumferential surface of the rotating drum 28 in the transfer area 58, and a transfer corona discharger 60 located adjacent to and downstream of the transfer corona discharger 60. A stripping static eliminator 62 is provided.

Further, at the right end of the lower support frame 4, a copy paper supply means, which is indicated by the number 64 as a whole, is provided.
A copy paper tray 66 is disposed at the left end of the tray. Between the copy paper supply means 64 and the copy paper tray 66,
A copy paper transport system, generally designated by the number 68, is provided for transporting copy paper as a sheet member through the transfer area 58. The copy paper supply means 64 includes a copy paper stand 70,
It includes a copy paper feed roller 72 disposed above the downstream end of the copy paper table 70. The copy paper feed roller 72 is selectively moved up and down and is driven to rotate in the direction shown by an arrow 74.

The copy paper supply means 64 further includes a copy paper supply roller 78 disposed downstream of the copy paper table 70 and rotationally driven in the direction shown by an arrow 76, and a copy paper separation means 80 disposed below the copy paper supply roller 78. Contains.

The copy paper separation means 80 includes a support member 84 rotatably mounted by a bin 82, and a separation member 86 made of a high friction material such as synthetic rubber and disposed on the upper surface of the support member 84. have

Support member 84 is resiliently biased in a clockwise direction by suitable spring means (not shown), thus forcing separation member 86 resiliently against copy paper feed roller 78. In the copy paper supply means 64 as described above, a layer of sheet-like copy paper of appropriate dimensions is manually fed to the copy paper tray 7.
inserted above 0.

Then, each time the copy paper feed roller 72 is lowered and rotated in the direction shown by the arrow 74, the upper copy paper in the copy paper layer is sequentially sent out, and the copy paper is further advanced by the copy paper feed roller 78. be done. Separation member 8
6 prevents copies other than the topmost copy paper from being advanced by the copy paper feed roller 78 when two or more copies are sent out at a time by the copy paper feed roller 72; In this way, the copy paper conveyance system 68
be supplied to The copy paper conveyance system 68 includes a pair of guide plates 8, a pair of conveyance rollers 92 that are rotationally driven in the direction shown by arrow 90, guide plates 94 and 96, a conveyance heald mechanism 100 that is rotationally driven in the direction shown by arrow 98, 102
A heating fixing roller pair 104 is rotated in the direction shown by
, a pair of guide plates 106, and a pair of discharge rollers 110 that are driven to rotate in the direction shown by arrow 108. Inside the upper heating roller 112 of the heating fixing roller pair 104,
Appropriate heating means 114 are provided. Further, a peeling member 116 is attached to the upper heating roller 112 to prevent the copy paper from being wrapped.

In the electrostatic copying machine as described above, the rotating drum 28
The charging corona discharger 32 charges the photoreceptor on the rotating drum 28 substantially uniformly to a specific polarity while the photoreceptor on the rotating drum 28 is rotated in the direction shown by the arrow 30. The image of the original is scanned and exposed onto the photoreceptor, thus forming an electrostatic latent image corresponding to the image of the original on the photoreceptor. During the above-mentioned scanning exposure, the document mounting means 10
, for example, is moved for scanning exposure from a scanning exposure start position indicated by a two-dot chain line 10A rightward to a scanning exposure end position indicated by a two-dot chain line 10B. Thereafter, the electrostatic latent image on the photoreceptor is developed into a toner image by a developing device 34. Next, the copy paper supplied from the copy paper supply means 64 and conveyed by the copy paper conveyance system 68 is brought into close contact with the circumferential surface of the rotating drum 28 in the transfer area 58, and the copy paper is brought into close contact with the circumferential surface of the rotating drum 28 in the transfer area 58.
The toner image on the photoreceptor is transferred onto copy paper by the action of . Thereafter, the copy paper is peeled off from the rotating drum 28 by the action of the static eliminator 62. The peeled copy paper is conveyed through a pair of heat-fixing rollers 104, during which time the toner image on the copy paper is heat-fixed, and then transferred to a copy paper tray 66.
is discharged to the top.

On the other hand, the rotating drum 28 continues to rotate, and the toner remaining on the photoreceptor after the transfer is removed from the photoreceptor by the action of the cleaning device 56.

Next, the photoreceptor is irradiated with neutralization light in the static elimination area 54, and residual charges on the photoreceptor are eliminated.

Process unit Next, the illustrated process unit 16 will be described with reference to FIG. 2 together with FIG.
The unit frame 22 in
It has a front wall 118 (FIG. 8) and a rear wall 120 which are arranged at intervals in the direction (perpendicular to the plane of the drawing), and between the front wall 118 and the rear wall 120 there is a rotating drum 28, a developing device 34, etc. and a cleaning device 56 are attached. Between the front wall 118 and the rear wall 120, a bottom wall 122, a left side wall 124, and a right side wall 126 are provided in addition to the above-mentioned top wall 44. On the bottom wall 122, the copy paper conveyed by the action of the copy paper conveyance system 68 is transferred to the rotating drum 2 in the transfer area 58.
A transfer opening 128 is formed to allow the right side wall 126 to be brought into close contact with the circumferential surface of the right side wall 126, and the lower end of the right side wall 126 serves as the supported rail portion 26.

The rotating drum 28 is rotatably mounted between the front wall 118 and the rear wall 120. When the process unit 16 is detachably attached to the upper support frame 6, the rotating drum 28 is connected to a drive source (not shown) provided in the upper support frame 6.
(which constitutes the drive source of the electrostatic copying machine), and is rotationally driven in the direction shown by the arrow 30 by the action of the drive source.

Further, the developing bag 234 has a pair of end walls 130 (see FIG. 5) disposed inside the front wall 118 and the rear wall 120 of the unit frame 22 with an interval in the front-rear direction. Various walls 134 extending in the longitudinal direction are provided between the end walls 130.
,136,138°140.142,144. and 14
6 are provided, and the developing device 34 is connected to the wall 134,
It has three chambers partitioned by 136.degree. The toner storage chamber 152 is divided into a first chamber 154 and a second chamber 156.

Referring primarily to FIG. 2, in the specific example, the wall 136
A first chamber 154 is defined by the walls 13B and 14ν. New, unused toner (not shown) is stored in the first chamber 154 in advance. The amount of new toner to be filled into the toner storage chamber 152 will be described later. Further, the second chamber 156 is connected to the wall 14
0 approximately U-shaped portion 140a and the wall 13
8. In the specific example, the second
As shown in FIGS. 1 and 2, the chamber 156 is arranged at the upper end of the first chamber 154 and extends in the front-rear direction similarly to the first chamber 156. Toner removed from the rotating drum 28 is fed to the second chamber 156 as will be described later, and the toner is transferred from the second chamber 156 to the first chamber 154.
supplied to

The bottom of the toner storage chamber 152, in the specific example, the first chamber 1
A toner discharge opening 158 is formed at the bottom of 54 . The toner discharge opening 158 is formed substantially from one end to the other end in the width direction (the above-mentioned front-to-back direction) of the toner storage chamber 152, and an elongated cylindrical toner supply roller 160 is disposed in the toner discharge opening 158. . The toner supply roller 160 is rotated in the direction shown by an arrow 162, and as a result of this rotation, the toner in the toner storage chamber 152 is supplied to the developing chamber 148 through the toner discharge opening 158.

The left side of the developing chamber 148 facing the rotating drum 28 is open. In the developing chamber 148, an application means 16 is provided.
4, a developer stirring means 166, and a guide plate 168 are provided. The application means 164 includes a cylindrical sleeve 172 that is rotatably driven in the direction indicated by an arrow 170, and a stationary permanent magnet 174 that is disposed within the sleeve 172 and has a plurality of magnetic poles spaced apart in the circumferential direction.
It can be composed of. The stirring means 166 is
It has a plurality of spiral blades 178 that are rotationally driven in the direction shown by an arrow 176 to agitate the developer in the developing chamber 148 and supply it to the application means 164. An ear cutting means 180 is formed on a wall 146 that defines the upper left wall of the developing chamber 148 and projects toward the sleeve 172 of the application means 164. The cutting means 180 is magnetically held on the surface of the sleeve 172 and acts on the moving developer to remove excess developer. Further, the above-mentioned ear cutting means 180 is attached to the above-mentioned wall 146.
A toner concentration detector 182 is provided above the toner concentration detector 182 . Detector 182, which may be of well-known form, is located in development chamber 148.
It has a detection surface exposed inside, and detects the toner concentration of the developer removed from the application means 164 by the action of the ear cutting means 180.

Further, the developer storage chamber 150 is arranged above the developing chamber 148. In this developer storage chamber 150, a starter developer (carrier and toner are mixed at a predetermined mixing ratio of about 19:1, for example).
A new developer (mixed at a weight mixing ratio of 1) is stored in advance. It is necessary to prevent such start developer from leaking from the developer storage chamber 150 to the development chamber 148 until the time when the developing device 34 is actually used. It is preferable to configure it as disclosed in the specification and drawings of the utility model registration application (title: Developing device for image generator) filed by the applicant on May 30th.

In the developing device 34 as described above, at the beginning of use, the start developer contained in the developer storage chamber 150 is first supplied to the developing chamber 148 as required. When performing development, the stirring means 166 is rotated in the direction shown by arrow 176 within the developing chamber 148, thereby stirring the developer and charging the toner to a predetermined polarity, and also transferring the developer to the application means 164. will be sent towards. The sleeve 172 in the application means 164 is rotated in the direction shown by the arrow 170, and the developer fed by the action of the stirring means 166 is transferred to the magnet 17 disposed within the sleeve 172.
It is held on the surface of the sleeve 172 by the magnetic attraction force of 4, and is conveyed in the direction shown by the arrow 170 as the sleeve 172 rotates.

Then, the sleeve 172 is cut by the action of the ear cutting means 180.
Excess developer retained on the surface is removed. The removed developer is moved upward along the inner surface of the wall 146, flows down on the guide plate 168 toward the stirring means 166, and is stirred by the stirring means 166 again. On the other hand, it is held on the surface of the sleeve 172 and further
The developer conveyed in the direction indicated by 70 is transferred to the rotating drum 28.
The toner in the developer is applied onto the photoconductor in correspondence with the electrostatic latent image on the photoconductor, and the electrostatic latent image is developed into a toner image. be done.

When the toner concentration of the developer is reduced by such a development action, the detector 182 generates a signal which causes the toner supply roller 160 to rotate in the direction indicated by arrow 162, thus filling the toner storage chamber 152, i.e. first chamber 15
The toner in the developing chamber 1 passes through the toner discharge opening 158.
48.

Next, the cleaning device 56 will be explained.
8 and a pair of end walls (not shown) disposed inside the rear wall 120 at intervals in the front-back direction, and various walls 184 extending in the front-back direction between these pair of end walls. 18
6 and 188 are provided. Cleaning device 56
An elastic blade 192 is attached to the upper surface of the wall 188 by a mounting member 190. The free end of the elastic blade 192 constituting the toner removing means is pressed against the circumferential surface of the rotating drum 28 with a required pressure. The cleaning device 56 also includes a toner collection chamber 194 defined by the walls 184, 186 and 188. The toner recovery chamber 194 is open at a portion facing the rotating drum 28, and a sealing member 196 is disposed at the open opening. The sealing member 196 is attached to the wall 18
4, and its free end is brought into contact with or close to the circumferential surface of the rotating drum 28. As described above, when the rotating drum 28 is rotated in the direction shown by the arrow 30, the residual toner remaining on the surface of the photoreceptor is removed by the action of the elastic blade 192. Then, the thus removed toner is guided by the sealing member 196 and the inner surface of the wall 184 and is collected into the toner collection chamber 194 as required.

In the electrostatic copying machine as described above, a toner transporting means is further provided in conjunction with the cleaning device 56 and the developing device 34, and the action of the toner transporting means causes the toner to be collected in the toner collection chamber 194. The collected toner is stored in the toner storage chamber 15.
2. To further explain with reference to FIGS. 3 and 4 as well as FIG. 2, in the specific example, an opening is formed at a required portion of one end wall of the cleaning device 56 (the end wall located at the front in the front-rear direction). Further, an opening is formed at a required portion of one end wall of the developing device 34 (the end wall located on the left side and forward in the front-rear direction in FIG. 5), and both openings form a U-shaped hollow cylinder. They are communicated by a member 200 (indicated by a two-dot chain line in FIG. 3). Toner transport means 19B includes an elongated helical member 202.

The spiral member 202 has an intermediate portion 204a located inside the hollow cylinder member 200, one end 204b located at the bottom of the toner collection chamber 194 of the cleaning device 56, and the other end 204c located inside the toner storage chamber 152. second chamber 15
It is located within 6.

More specifically, in the toner collection chamber 194, the one end 204btZ of the spiral member 202 extends in the width direction of the toner storage chamber 194, that is, in the front-rear direction, and a shaft 206 provided at one end is used for cleaning. It is rotatably attached to the other end wall of the device 56 (the end wall located at the rear in the longitudinal direction).

The shaft portion 206 penetrates the other end wall and protrudes rearward,
A gear 208 is attached to this protruding end. gear 20
8 is a large gear 21 provided at the rear end of the rotating drum 28
0, and when the rotating drum 28 is rotated in the direction shown by the arrow 30, the gear 208 is meshed with the large gear 210.
is rotated in the direction shown by arrow 212. Further, in the second chamber 156 of the toner storage chamber 152, the other end 204c of the spiral member 202 extends in the width direction of the second chamber 156, that is, in the front-back direction, and is provided at the other end. The shaft portion 214 is connected to the other end wall 130 (the fourth
(Fig. 5) is rotatably mounted. The helical member 202 has shaft portions 206 and 214 at both ends thereof,
Other parts have no shaft and are hollow.
Further, a gear 208 is spirally wound to transport the toner, as shown in the third example. Such a spiral member 20
In relation to the other end portion 204c of the wall 140, the substantially U-shaped portion 140a of the wall 140 is preferably configured as follows, for example. That is, as shown in FIGS. 4 and 5, the portion 140a
The height of one side wall portion (the right side wall portion in FIG. 2) is gradually decreased from the one end (front end in the front-rear direction) to the other end (rear end in the front-rear direction) in the width direction of the second chamber 156. In the illustrated example, the bottom portion 140b of the portion 140a that defines the second chamber 156 (the approximately U-shaped bottom portion that defines the bottom portion of the second chamber 156) is the first portion. The height of one side wall portion of the wall portion 140a, which the toner in the second chamber 156 can overcome, is raised from one end (front end) to the other end (rear end) in the width direction of the second chamber 154. The width of the first chamber 154 decreases from one end to the other end in the width direction.

Incidentally, as shown in FIG. 3, the sleeve 17 of the application means 164
2, the shaft portions 218a and 218b provided at both ends thereof are rotatably attached to the pair of end walls 130 of the developing device 34, and the stirring means 16'6 is also provided at both ends thereof. The shaft portions 220a and 220b are rotatably mounted on the pair of end walls 130. The shaft portion 218b of the sleeve 172 is connected to the end wall 130 (FIG. 4).
The shaft portion 220b of the stirring means 166 also passes through the end wall 130 and projects rearward, and a gear 222 is attached to this protruding end. There is. Gears 222 and 224 are drivingly coupled via pinion 226 . Therefore, the drive source (not shown) of the copying machine causes the gear 222 to move toward the arrow 2.
28 (thereby, the sleeve 1
72 is rotated in the direction shown by arrow 170), and gear 2
26, gear 224 is rotated in the direction shown by arrow 230 (thereby rotating stirring means 166 in the direction shown by arrow 176).

In the copying machine equipped with the above-mentioned toner transfer means 198, when the rotary drum 28 is rotated in the direction shown by the arrow 30, the helical member 2 is transferred through the large gear 210 and the gear 212.
02 is rotated as required. That is, the toner collection chamber 19
At one end 204b located within 4, the arrow 232
The toner rotated in the direction shown in FIGS. 2 and 3 and collected in the toner collection chamber 194 as described above is transferred to the toner collection chamber 19 by the action of the spiral member 202.
4 from the rear end to the front end in the direction shown by arrow 216. The thus transferred toner passes through the hollow cylinder member 200 and is further supplied into the second chamber 156 of the toner storage chamber 152. At the other end 204c of the helical member 202 located within the second chamber 156, the arrow 234 (FIGS. 2 and 3)
The toner rotated in the direction shown in FIG. It is transported towards the end in the direction shown by arrow 216. When the toner is transferred through the second chamber 156, the toner exceeds the upper surface of one side wall (right side wall) of the oval-shaped wall portion 140a of the wall 140 due to the action of the spiral member 202. - the toner that has exceeded the upper surface of the side wall is supplied onto the toner present in the first chamber 154; and,
After the new toner previously stored in the first chamber 154 is supplied to the developing chamber 148 by the action of the toner supply roller 160, this reused toner (one-time use toner that has been used once for development) is supplied to the developing chamber 148. be done. In the specific example, the height of one side wall portion of the wall portion 140a that the toner passes over is gradually decreased from the front end to the rear end of the second chamber 156. At the front end, a relatively large amount of toner exists but the toner supply rate is small, while at the rear end, although there is relatively little toner, the toner supply rate is large, thus filling the second chamber. Toner from 156 is supplied substantially uniformly across the width of first chamber 154 .

In the specific example, an opening 2 is provided at the bottom of the rear end of the second chamber 156.
36 is formed, therefore, the toner transferred in the second chamber 156 to the rear end in the direction shown by the arrow 216 is supplied to the first chamber 154 through the opening 236.

This electrostatic copying machine is further equipped with a unit life display mechanism shown in FIGS. 6 to 8.

In a specific example, the unit life indicator ti240 is disposed in relation to the rotating drum 28 and includes a small pawl bundle 242 and a large pawl wheel 244 that are rotated in a predetermined direction. The small claw bundle 242 is rotatably attached to a pin 246 implanted on the inner surface of the front wall 118 of the unit frame 22. Small nail bundle 24
2 is further provided with a locking member 250, which has a biasing means (not shown) such as a spring member.
is biased to engage pawl 24B by.

Therefore, the locking member 250 is connected to the arrow 252 of the small claw bundle 242.
Although rotation in the direction shown in (Fig. 7) is permitted,
Rotation in the direction opposite to the direction indicated by arrow 252 of No. 2 is reliably prevented. Further, in the specific example, the large ratchet wheel 244 is fixed to the inner surface of a rotating member 254 made of a disc, and the rotating member 254 and the large ratchet wheel 244 are connected to the front wall 1 of the unit frame 22.
It is rotatably attached to a bottle 256 implanted on the inner surface of 18.

The pawl wheel 244 is further provided with a locking member 258 which is also biased into engagement with the pawl 260 by a biasing means (not shown) such as a spring member. Therefore, the locking member 25B is connected to the arrow 2 of the large ratchet wheel 244.
Rotation in one direction shown by 62 (FIG. 7) is allowed, but rotation in the opposite direction to the direction shown by arrow 262 of the large pawl wheel 244 is reliably prevented. In the life display mechanism 240, further,
A large claw wheel 2 is attached to the outer surface of the small claw bundle 242 (the left surface in FIG. 6).
An operating pin 264 that can engage with 44 pawls 260 is implanted. On the other hand, a small claw bundle 24 is also provided on the front end surface of the rotating drum 28.
An operating pin 266 that can engage with the second pawl 248 is implanted. With this structure, when the rotating drum 28 makes one revolution as described above, the actuating pin 266 acts on the pawls 248 of the small pawl bundle 242 to rotate it by a predetermined angle in the direction shown by the arrow 252 (i.e., one pawl). ),
When the small pawl bundle 242 rotates once as described above, the operating pin 264 acts on the pawl 260 of the large pawl wheel 244 to rotate it by a predetermined angle in the direction shown by the arrow 262 (that is, rotate it by one pawl). ).

In connection with this configuration, a first display section 266a and a second display section 266 are provided on the outer surface of the rotating member 254.
b and the third display section 266C are provided in a cloth shape. In a specific example, the first display section 266a is colored, for example, green, the second display section 266b is colored, for example, yellow, and the third display section 266c is colored, for example, red. . On the other hand, a circular opening 268 (FIG. 8) is formed in a required portion of the front wall 118 of the unit frame 22.
The first through this opening 26th from the outside of the unit frame 22.
The display section 266a, the second display section 266b, and the third display section 266c are visible.

Relationship between the amount of toner filled in the toner storage chamber and the display on the life display mechanism Next, with reference mainly to FIGS. 2 and 8, the amount of new toner filled in the toner storage chamber and the lifespan. The relationship with the display in the display mechanism 240 will be explained. In general, the properties of toner change when it is subjected to development, and if it is used for development more than once, its properties tend to change significantly and the image quality tends to deteriorate significantly. Therefore, in the electrostatic copying machine, new toner filled in the toner storage chamber 152 and toner removed from the photoconductor 1
98 (FIG. 3), the consumption of once-used toner (toner used once for developing an electrostatic latent image) transferred to the toner storage chamber 152 is made to correspond to the life of the photoreceptor of the rotating drum 28. It is important to configure the process unit 16 so that the entire process unit 16 substantially reaches the end of its service life when the new toner and the once-used toner are used. To explain further, in the illustrated example, approximately 2000 copying steps are performed (=rotating drum 28 is used for each copying step).
(substantially rotates 4 times, and the rotating drum 28 rotates approximately 2,000 times) and the photoreceptor on the surface of the rotating drum 28 substantially reaches the end of its lifespan.The total amount of the new toner and once-used toner is approximately 2,000 copies. Get the amount you need to get it.

-i, the amount of new toner previously filled in the toner storage chamber 152 is set to a (g), and the toner transfer efficiency is set to B (X100%) (hereinafter, the case where a standard original is used as the original is assumed) ), the total consumption of toner transferred to the copy paper P (g) when approximately 2000 copies are made in a form that does not reuse toner is P = a B (note that the filling amount a is (This is the amount of toner corresponding to the life of the photoreceptor when the toner is not reused).

On the other hand, when approximately 2000 copies are made in the form of reusing toner as in this specific example, the total consumption Q (g) of toner transferred to copy paper is Q=YB+ (Y-YB
)B (Note that the filling amount Y is the amount of toner corresponding to the life of the photoreceptor when the toner is reused once).

When copying 2000 sheets of the same original (standard original), the total amount of toner transferred to the copy paper is virtually the same regardless of whether or not toner is reused. The total consumption P of toner and the total toner consumption i1Q when toner is reused once are substantially equal (P
=Q), therefore, aB=YB+ (Y-YB)B holds true. From this formula, the toner filling amount Y is determined as follows: Y=--B. As described above, in this specific example, the filling amount Y of new toner to be filled into the toner storage chamber 152 is
If the toner filling amount is a(g) when the toner is not reused, and the transfer efficiency is B(X100%), then Y = −(g) −B, and by filling such amount Y of toner, ,
The consumption of new toner and this once-used toner (in other words, the lifespan of the developing device 34) substantially corresponds to the lifespan of the photoreceptor.

Transfer efficiency B will be discussed here, and in general, toner transfer efficiency differs somewhat depending on the type of photoreceptor, and also changes somewhat depending on the ambient conditions in which the electrostatic copying machine is used, such as humidity, humidity, etc. , it also changes depending on the resistance value of the copy paper onto which the toner image is transferred. Therefore, if the reference transfer efficiency in the standard setting state is b (X100%), the transfer efficiency B can be expressed as B=b+α α: compensation value. For example, humidity 20℃, humidity 55%
If we further assume that the standard setting condition is when copying paper with a normal resistance value is used, the standard transfer efficiency in such a condition is:
When selenium is used as the photoreceptor, it is approximately 0.75 (
Therefore, it becomes 75%). The compensation value α is experimentally determined to be within the range of 1□≦α≦□ depending on changes in various conditions. Such a compensation value α will be smaller when the humidity of the atmosphere in which the image generator is used is relatively high, whereas it will be smaller when the humidity of the atmosphere is relatively low, for example in connection with the fact that the transfer efficiency decreases with increasing humidity. Sometimes it gets bigger. Therefore, when the humidity is relatively high, it is preferable that the filled amount Y of new toner is somewhat less than in the standard setting state, whereas when the humidity is relatively low, the filled amount Y of new toner is preferably slightly smaller than in the standard setting state. It is also preferable to increase the amount somewhat. In addition, this compensation value α becomes large when the resistance value of the copy paper to which the toner image is transferred is relatively large, in relation to, for example, that the transfer efficiency increases as the resistance value of the copy paper increases; It becomes small when the resistance value of the copy paper is relatively small. Therefore, when the resistance value of the copy paper is relatively large, it is preferable that the filling amount Y of new toner is somewhat larger than that in the standard setting state.
On the other hand, when the resistance value of the copy paper is relatively small, it is preferable that the amount of new toner filling IY is somewhat less than the standard setting state.

In connection with the above, in the electrostatic copying machine of the specific example, the opening 26 formed in the front wall 118 of the unit frame 22
8, the first display section 266a, the second display section 266b, and the third display section 266C are set, for example, in the following relationship. That is, until approximately 1,500 copies are produced, in other words, the rotating drum 28 rotates approximately 6,000 times, the opening 2 is closed.
The first display section 266a is substantially visible through 68,
After approximately 6,000 rotations, the boundary between the first display section 266a and the second display section 266b is positioned substantially at the center of the opening 268. Further, when approximately 1,500 to 1,900 copies are produced, in other words, the second display portion 266b is substantially visible through the opening 268 until the rotating drum 28 rotates from approximately 6,000 rotations to 7,600 rotations, and when approximately 2,000 copies have been produced, the second display portion 266b is visible. As shown in FIG. 8, the boundary between the second display section 266b and the third display section 266C is the opening 2.
68.

Further, approximately 2000 copies are generated, in other words, the rotating drum 28 rotates approximately 5ooo (approximately 2000 copies).
When 00 copies are produced, the photoreceptor on the rotating drum 28 substantially reaches the end of its life, and the new toner filled in the toner storage chamber 152 and this once-used toner are substantially discharged and consumed, and the developing device f34 is also consumed. When the unit life display means 240 reaches the end of its lifespan, only the third display section 266c becomes visible through the opening 268.
indicates to the operator that the entire process unit 16 is substantially at the end of its life.

Although not shown, the unit life display means 24
0 or unit life display means 24
Instead of displaying 0, the copying machine may be configured to stop operating after approximately 2000 copies have been produced, and to make it virtually impossible to produce copies unless it is converted to a new process unit. Also, a life indicator lamp (not shown)
You can also make it light up.

In the above-mentioned electrostatic copying machine, the new toner stored in the toner storage chamber 152 and the once-used toner removed from the photoreceptor after transfer and transferred by the action of the toner transfer means 198 are effectively dispensed. When the photoreceptor is consumed, the life of the photoreceptor is substantially reached, and the entire process unit 16 must be replaced. Therefore, toner can be used effectively, significant deterioration in image quality due to changes in toner characteristics can be avoided, and the amount of toner filled in toner storage chamber 152 can be minimized. Furthermore, in connection with this, the toner storage chamber 152 and the like can be made smaller, thereby achieving further miniaturization of the copying machine.

<Example> A copying process was performed 2000 times using a copying machine under the following conditions. A standard manuscript of JISAA size with an image ratio of 8% (ratio occupied by the image on the front surface of the manuscript) was used. Furthermore, selenium was used as the photoreceptor, and it was placed on the circumferential surface of a rotating drum with a diameter of 401 m.

The image generation conditions were as follows.

Applied voltage of corona discharger for charging...4.5 KV Applied voltage of corona discharger for transfer...5.6 KV Applied voltage of corona discharger for peeling...4KV (AC) Sleeve of magnetic brush mechanism Diameter...20n+developing bias voltage...250V The characteristics of the copy paper to which the toner formed on the photoreceptor is transferred are as follows: humidity 20°C, 3955
The percentages were as follows:

Weight of paper: 64 g/thickness of paper: 80 μm Volume resistance: 3.8 x 10” 97 cm In addition, a two-component developer consisting of carrier and toner was used as the developer. The characteristics of the carrier and toner were as follows. Ta.

Characteristic volume center particle diameter of carrier: approx. 80μm Saturation magnetization: 65±5eφ/g apparent density ・
...2.57g/c is fluidity -25sec / 50g toner characteristic volume center particle diameter...11μm Apparent density -0.35±0.05g/cell Dielectric constant ...2.70 Heat resistance ... 65°C Under the image generation conditions shown above, humidity 20°C, humidity 55
After producing 2,000 copies under an atmosphere of 100 g, the total amount of toner consumed (total amount of toner supplied from the toner storage chamber) was measured to be 100 g. Also, at this time, 20 g of toner was collected in the toner collection chamber. From the above results, the toner transfer efficiency was substantially 75%.

Based on the above results, 2000 copying steps were performed with Y=--B. the result,
Good copies without significant deterioration in image quality could be obtained up to 2000 copies.

Modifications and Modifications> Although a specific example of an electrostatic copying machine as an example of an image generator configured according to the present invention has been described above, the present invention is not limited to such specific example, and the present invention Various modifications and variations can be made without departing from the scope of the invention.

For example, in the illustrated example, the volume of the toner collection chamber is reduced, the volume of the toner storage chamber is increased, and new toner is filled into the toner storage chamber, but the present invention is not limited to this. A type in which the volume of the toner collection chamber is increased and the volume of the toner storage chamber is decreased to fill new toner into the toner collection chamber (for example, the patent application filed by the applicant on September 16, 1988) -2
15938)). In such a case, the toner may be transferred from the toner collection chamber to the toner storage chamber depending on the amount of toner supplied from the toner storage chamber to the development chamber, or the toner may be transferred depending on the amount of toner consumed by the developing action of the magnetic brush mechanism. The toner may be directly supplied from the toner collecting chamber to the developing chamber by the action of the toner transporting means.

Further, for example, in the illustrated specific example, the toner storage chamber is filled with a predetermined amount of toner and new toner is not replenished, but the present invention is not limited to this, and new toner is replenished into the toner storage chamber. The present invention can be similarly applied to a configuration in which a predetermined number of toner cartridges are selectively installed in a toner storage chamber, for example.

Furthermore, for example, in the specific example shown in the drawings, the present invention is applied to a developing device that uses a so-called two-component developer consisting of a carrier and a toner, but similarly,
The present invention can also be applied to a developing device that uses a so-called component-based developer consisting only of toner. In such a case, there is no need for a developer storage chamber for storing the start developer, stirring means, etc.

[Brief explanation of the drawing]

FIG. 1 is a simplified sectional view showing an example of an electrostatic copying machine as an example of an image generating machine constructed according to the present invention. FIG. 2 is a sectional view showing a process unit in the electrostatic copying machine of FIG. 1. FIG. 3 is a perspective view of the toner transport means and related elements in the electrostatographic transfer machine of FIG. 1; FIG. 4 shows the second developing device in the electrostatic copying machine shown in FIG.
FIG. 3 is an enlarged perspective view showing the chamber and its vicinity. 5 is a side sectional view showing an enlarged view of the chamber of FIG. 2 shown in FIG. 4 and its vicinity; FIG. 6 is a plan view showing the vicinity of the front end of the rotating drum in the electrostatic copying machine of FIG. 1; FIG. FIG. 7 is a front view showing a unit life display mechanism in the electrostatic copying machine of FIG. 1. FIG. 8 is a front view showing a part of the process unit in the electrostatic copying machine of FIG. 1. 2... Housing 4... Lower support frame 6... Upper support frame 16... Process unit 22... Unit frame 28... Rotating drum 152... Toner storage chamber 164... Application means 192...Elastic blade 194...Toner collection chamber 198...Toner transport means 240...Unit life display mechanism Fig. 6 22 Fig. 8

Claims (1)

[Scope of Claims] 1. An electrostatic photoreceptor, an electrostatic latent image forming means for forming an electrostatic latent image on the surface of the photoreceptor, and an electrostatic latent image forming means for forming an electrostatic latent image on the surface of the photoreceptor. The developing device includes a developing device that develops a toner image, and a cleaning device that removes residual toner remaining on the surface of the photoconductor after the toner image is transferred. an application means for applying toner to an electrostatic latent image formed on the surface of the photoconductor; the cleaning device includes a toner removal means for removing residual toner remaining on the surface of the photoconductor; a toner collection chamber for collecting the removed toner, and a toner transfer means for transporting the toner collected in the toner collection chamber to the toner storage chamber in association with the cleaning device and the developing device. In an image producing machine comprising: at least the electrostatographic photoreceptor and the developing device forming a process unit removably mounted on a support structure; An image generating machine characterized in that it is configured such that once used toner removed from a surface and transferred to the toner storage chamber by the action of the toner transfer means is consumed, the service life is substantially reached. 2. The image generating machine according to claim 1, wherein the process unit also includes the cleaning device. 3. The new toner of the predetermined filling amount is stored in the toner storage chamber of the developing device in advance, and the new toner stored in the toner storage chamber and the toner removed from the surface of the photoreceptor are mixed with each other. 3. The image generating machine according to claim 1, wherein once the once-used toner transferred to the toner storage chamber by the action of the toner transfer means is consumed, the process unit substantially reaches the end of its service life. 4. The filling amount Y of the new toner is: Y=a/(2-B) a: Toner filling amount when the toner is not reused B: Transfer efficiency Claims 1 to 3 The image generator according to any one of the above. 5. The transfer efficiency B is B=b+α, where b is the reference transfer efficiency and α is the compensation value, and the compensation value α is −10/100≦α≦10/100. The image generator according to item 4. 6. When the humidity of the atmosphere in which the image generator is used is relatively high, the compensation value α is set small, and therefore the filling amount Y of the new toner is somewhat small, whereas when the humidity of the atmosphere is relatively low, the compensation value α is set to a small value. 6. The image generator according to claim 5, wherein the compensation value is set large, so that the new toner filling amount Y is somewhat larger. 7. When the resistance value of the sheet member to which the toner image formed on the surface of the photoreceptor is transferred is relatively large, the compensation value α
is set to be large, so that the filling amount Y of the new toner is somewhat large.On the other hand, when the resistance value of the sheet member to which the toner image is transferred is relatively small, the compensation value α is set to be small, and therefore the filling amount Y of the new toner is relatively small. The image generator according to claim 5 or 6, wherein the filling amount Y is somewhat small.