JPS63193165A - Developing device - Google Patents

Abstract

PURPOSE:To equalize the toner concentration, and also, to improve the picture quality by forming the diameter of a second spiral for stirring a developer in a developing container and carrying it, larger than the diameter of a first signal. CONSTITUTION:The first spiral 100 for supplying a developer to a developing roller 81, while stirring it in a developing container is formed by winding a continuous spiral blade 100a to a shaft 100b, and the second spiral 101 is formed by attaching plural blades 101a of a shape which has notched an elliptical plate whose outside diameter is larger than that of the first spiral 100, to half, to a shaft 101b so that the direction becomes alternate by a half rotation each. According to this constitution, the carrying force of the developer of the first spiral 100 and the second spiral becomes equal, and also, a toner and the developer are stirred enough by the second spiral having a large stirring force.

Description

Detailed Description of the Invention [Objective of the Invention] (Industrial Field of Application) The present invention provides a system in which, in a copying machine, a printer, etc., the developer that is stirred and conveyed in the developing container by two spirals is moved by the developing roller. , relates to an improvement of a developing device for imparting an electrostatic latent image.

(Prior Art) In an image forming device such as an electrophotographic device, when a two-component developer consisting of a carrier and a toner is used as a developer, the toner concentration in the developer container is kept constant to ensure sufficient development concentration. In order to obtain this, new toner must be replenished into the housing from time to time, but in order to supply this replenished toner to the developing roller.

In order to make the toner concentration uniform, it is necessary to sufficiently stir the toner together with a certain developer in the developing container and mix it uniformly into the developer. For this reason, a device as shown in FIG. 15 has conventionally been used. That is, in this device, the developing container)l
:The developing roller (201) in d (200) and the first
spiral (202) and second spiral (203
), new toner (not shown) is supplied from the toner supply port (204) to the end of the second spiral (203) in the developer container (200). It circulates in the direction of arrow Q while being stirred together with a certain developer and is supplied to the developing roller (201).

However, in such a device, the diameters of the first spiral (202) and the second spiral (203) are approximately the same in order to equalize the conveyance speed, and the developing roller (201) When the developer is circulated fast enough to supply the 'fi amount of developer.

The agitation of the developer is insufficient and the toner density on the developing roller (201) becomes non-uniform, which in turn causes the image density to become non-uniform and the image quality to be significantly degraded.

(Problem to be solved by the invention) Conventionally, this is because the two spirals have the same diameter.

There is a problem in that the developer is not sufficiently stirred, resulting in uneven toner density and resulting in poor image quality.

Therefore, the present invention aims to eliminate the above-mentioned drawbacks, and between circulating the developer in the developer container and supplying it to the developing roller,
To provide a developing device capable of eliminating toner density unevenness by sufficiently stirring replenished new toner into a developer and obtaining a high-quality image with uniform image density.

[Structure of the invention]

(Means for Solving the Problems) In order to solve the above problems, the present invention provides a second spiral having a larger diameter than the first spiral in the developing container.

(Function) According to the present invention, the second spiral transports the developer at the same speed as the first spiral and sufficiently stirs the developer with a stirring force greater than that of the first spiral. This prevents toner density unevenness and allows high-quality images to be obtained.

(Embodiment) An embodiment of the present invention will be described below with reference to FIGS. 1 to 13. First, FIGS. 1 and 2 are front and rear external perspective views of a laser printer main body (10), which is the development forming apparatus of the present invention, and the main body (10) has an upper cover (11), a lower front cover ( 12), covered with a lower cloth cover (13). A Sansui cover (14) is provided on a part of the upper cover (11), and the - side (
14a), and a unit (31) to be described later is mounted on the right side of the upper cover (11).
A stone wheel cover (16) is provided on the rear surface of the upper cover (11), which can be opened and closed around the negative side (16a) for replacing etc. 1
Multi-core cover (17) that can be opened and closed around 7a)
is provided.

Furthermore, an interface connector (18) is provided on the side surface of the lower cover (12) for transmitting and receiving signals from an external computer, word processor, etc. (not shown), which is the host system of the main body (10). is provided with a power cord (20), a power switch (21), and a ground terminal (22).

Furthermore, a paper feed section (24) into which a removable paper feed cassette (23) is inserted is provided at the lower front of the main body (lO), and a paper output tray (26) is removably attached above it. There is. Furthermore, a control panel (27) consisting of an indicator lamp and a switch is provided in front of the upper blade bar (11).

Next, FIG. 3 shows the inside of the main body (lO), which is an image carrier incorporated in a unit (31) which will be described in detail later, and has a diameter of approximately:
Around the photoreceptor drum (32) of lO(+on+),
A developing device (36) which is incorporated into units 1 to (31) together with a charging device (33) consisting of a scorotron charger, a laser optical system (34), and a photosensitive drum A (32), and which performs development and cleaning at the same time. An irradiation lamp device (76), a transfer device (37) consisting of a corotron charger, and a static elimination lamp (38) are arranged in this order. Furthermore, the main body (10)
At the tip of the paper feed cassette (23) at the bottom, a paper feed roller (40) made of a rubber material with a partially cut out cross-section is provided so as to be able to come into contact with the sheet paper (41) that is the transfer material. , 1 from the paper feed cassette (23) using the separation claw (23a).
The uppermost sheet of paper taken out is fed to aligning rollers (43a) and (43b) via first sheet paper guides (42a) and (42b). Also, aligning rollers (43a), (43
In front of b), a first paper detection device (44) consisting of a first lever (44b) having a first magnet (44a) at the other end and a first reed switch (44c) is provided. . Fourth, above the main body (10) are aligning rollers (43a) and (43b) as well as a paper output tray (26).
), a second sheet paper guide (/16) forming a conveyance path for the sheet paper (41), an intermediate roller (47a),
(4'7b), the third sheet paper guide (48), and the heater (50a) are built in, and the thermistor (50b)
A fixing device (52) consisting of a heat roller (50) and a press roller (51) that detect 1λ degree, and a paper ejection roller (53).
a) , (5:lb) is sunk. Further, in front of the paper ejection rollers (53a) and (53b), there is a second roller at the other end.
a second lever (5) having a magnet 1-(54a);
4b) and a second reed switch (54c). Nao (55)
is a control unit that controls each image forming apparatus, a control panel (27), and the like.

Among the above devices, the laser optical system (34) uses a laser beam (
A polygon mirror (62) is rotated at high speed by a mirror motor (61) in order to scan the laser light (60a) that is oscillated and focused by a collimator lens or a compressor lens (not shown). ), and a lens system (6:3) that irradiates the photosensitive drum (32) with a laser beam (60a) reflected by a polygon mirror (62).

Next, the unit (31) that is integrally equipped with the photoreceptor drum (32) and the developing device (36) will be described in detail. Fu L
, -m (70) l:t, , main body (10) inner (7) -/L/ (10a), the first fitting to (10b)
The guide (70a) and the second guide (70b) allow the photosensitive drum (3) to be freely attached to and detached from the main body (10).
2) and the developing device (36), and a recessed I cover (71) on the top surface which also serves as a lid for the developing device (36).
The sheet paper (4) is moved together with the second sheet paper guide (46).
The sheet paper (41) is shaped like a guide and forms part of the conveyance path for conveying the sheet paper (41) to the transfer position.
The covering cover (71) is also inclined so that the conveying direction of the photoreceptor drum (32) is inclined inward by fq1 from the tangential direction of the photoreceptor drum (32). In addition, the J- side of the covering cover (71) has ribs (7
1a) is formed, and the lower intermediate roller (47b) is urged upwardly by a leaf spring (not shown) so as to follow the upper intermediate roller (47a) connected to a drive unit (not shown). )have. Note that this lower intermediate roller (
47b) is largely chamfered on both sides so as not to interfere with the attachment/detachment operation of the unit (31). Further, (72) is a handle used when unit (31) al1 is attached to the attachment part (72).
It is rotatably attached at the rib (71a) and taken out from the four parts (73) formed on the cover (71) when in use, while the rib (71a)
) is housed in the recess (73) so as not to protrude from the sheet paper (
41) to reduce the resistance. Nao (74)
- of the protective cover (117) of the photosensitive drum 11, which will be described later.
This is a slit that supports the sides. Furthermore, the covering cover (71)
An irradiation lamp device (76) is installed at the tip of the photoconductor drum 1% (3
z) The entire surface is irradiated with light.

Also, both ends of the irradiation window (71b) are made of felt.

A cleaner (77) is attached that cleans both ends of the photoreceptor drum (32) and also serves as a brake on the rotation of the photoreceptor drum (32). On the other hand, 1 cover 1 cover (
71) A supply port (78) for supplying 1 hener into the developing device (36) is formed on the rear end side, and a cover (not shown) serves as a toner hopper for attaching the toner hopper (79) to the main body (lO). While it is opened by contact with (79),
When the toner hopper (79) is removed, it is attached so that it is biased by a spring (not shown) and closed. Note that (75a) and (75b) are holes (80a)' formed in the cover (71) and the side frames (82a) and (82b).

These are holes for screwing to (80b), (80c), and (80d).

Next, the developing device (36) will be described in detail. (81) is a developing roller, and the distance from the photosensitive drum (32) is approximately 2.
Side frame (82a), (82
b) is supported. That is, a three-pole magnetized magnet roller (84) is provided inside the aluminum sleeve (83), which is a sleeve-shaped conductive roller with a diameter of 30 (n, n), of the developing roller (81). body drum (
32), the first pole (84a) that is substantially opposite to the magnet has a magnetic force of 95
0 to 1050 [G], and this first pole (84a
) clockwise at intervals of 75 degrees, magnetic cuff 00 (G)
The second pole (84b) has a magnetic force of 500 (G), and the third pole (84b) has a magnetic force of 500 (G).
c). Further, at the drive side end of the developing roller (81), as shown in FIG.
A flange (86) supporting the aluminum sleeve (85) is press-fitted to maintain good electrical continuity between the aluminum sleeve (83) and the conductive shaft (85). In the center of the conductive shaft (85), there is a main body side fly 11 (87).
Point contact is made by a spring (88a) supported by a power source (88b).

A power supply blade (88) that applies a developing bias is brought into contact with the aluminum sleeve (83). Nao (90
) is a bearing that supports the conductive shaft (85) in the side frame A (82a), and (91) is the first gear for rotating the aluminum sleeve (83) via the conductive shaft (85). . Next, (92) is attached to the lower end of the developing container (93), about 1 inch from the developing roller (81).
It is a doctor blade installed through a gap of 8 (nwn), and the attachment made of plastic is fixed with a screw (94) that is a member. The tip of the doctor blade (92) is located at an intermediate portion between the second pole (87Ib) and the 37-i4 (84c) of the magnet roller (84), and a position where the lines of magnetic force are approximately parallel to the developing roller (81). Furthermore, a magnetic brush (not shown) using a developer consisting of negative polarity toner and carrier moves onto the developing roller (
81) at a position substantially parallel to the

Therefore, even if the height of the magnetic brush is regulated by the doctor blade (92), the stress on the developer can be made relatively small, and in turn, the aluminum sleeve (
y! required for the rotation of 83)! I am trying to reduce the A torque. The screw (93) is attached to the developer container (93).
) The developer leaking from the developer container (93) adheres to the exposed part of the screw (91) inserted from the outside, and this adhered developer is further influenced by the magnetism of the magnet roller (84) and forms a columnar shape. In addition, in order to prevent the risk of contact with the main body (10) and further leakage of the developing bias current, it is made of an insulating and non-magnetic plastic material.

Next, (100) and (101) move the developing roller (81) while stirring the developer (not shown) in the developing container (93).
) of non-magnetic conductive material (SUS 3)
04 (stainless steel)]. The first spiral (100) adjacent to the developing roller (81) has an outer diameter of 18 (
The continuous spiral first blade (100a) of an) is wound around the first spiral shaft (100b), while the partition wall (103) made of an aluminum plate with a thickness of 0.8 (rrtn) , a second spiral (100) separated from the first spiral (100)
01), a plurality of second blades (1 (lla)) each having a shape of an elongated circular plate with a minimum outer diameter of 24 (mn+) cut in half are rotated half a turn at a time on a second spiral shaft (101b). In other words, in the second spiral (lot), the new toner supplied from the supply port (78) is sufficiently mixed with the developer in the developer container (93). While stirring, the first spiral (100) does not have as much stirring power as the second spiral (101), but has almost the same conveying force as the second spiral (101) despite its small diameter. The first and second spirals (100) and (101) are caused by the magnetic field of the developing roller (81).
In order to prevent (101) from becoming magnetized and inhibiting the movement of the developer, it is made of SO3304 [stainless steel], a non-magnetic conductive material. Further, the partition wall (103) has a first spiral (100) from the second spiral (101) side at the end opposite to the supply port (78).
A conductor 11 (103a) for conveying the developer is formed on the side. In addition, the height of the partition wall (H) 3) depends on the degree of development,
The developer to be dropped onto the first spiral (100) from the developing roller (81) is transferred to the second spiral (101).
) side. This is because the developer jumps from the developing roller (81) to the second spiral (101) side.
This is to prevent the amount of developer from increasing on the ) side. 6 Furthermore, the spiral (100) and the second spiral (101)
At the 1 drive side end of each spiral shirt 1~(
100b), (lotb) are supported by the side frame (82) via bearings (not shown), and the first spiral shaft (100b) is driven by a main motor (not shown) at the end of the main body. is transmitted through the gear (104
) is attached, while the second spiral shaft (1
01b) A second gear (106) that meshes with the gear (10/I) is attached to the end. And more gear (104
) is meshed with a third gear (107) which meshes with the first gear (91) and rotates the aluminum 11 sleeve (83). Also, a cylindrical part (104) is provided at the end of the gear (104).
a) is provided and is an identification number for each individual unit,
A sticker (108) on which a 13-bit barcode-like binary pattern is printed is attached so that the 8192C] units can be identified. Furthermore, this seal (108),
The J- binary pattern is read by a photoelectric sensor (not shown) installed on the main body side and consisting of one light emitting diode and a phototransistor. On the other hand, in the control section (55),
A memory section (not shown) that does not disappear even when the power switch (2I) is turned off stores the identification number read by the photoelectric sensor (not shown) and also stores the number of sheets printed in each unit. , the number of sheets remaining in the lifespan of each unit is determined, and when the number of printed sheets reaches a preset number of sheets in the lifespan, the controller (55) displays this on the control panel (27).

Next, the photosensitive drum A (:32) will be described in detail. Flanges are fitted into both ends of the photoreceptor drum (32).
The flange (110) at the drive end has a leaf spring (
111) and a spring clutch (112) which is a one-way clutch. It forms a +4 dynamic transmission section (109). Furthermore, the flange (11
0) A protrusion provided around the central hole (110a) (
110b) is fitted into a bearing (113) provided on the side frame (82). - On the strength tree body side, a drive shaft (114) connected to a main motor (not shown) is provided, and the unit (31)
When attached to the main body, the drive shaft (114) is inserted into the hole (110a) of the flange (110), fitted with the spring clutch (112), and the drive is transmitted to the photoreceptor drum via the flange (110). (32), comes into contact with the leaf spring (111), and is electrically connected to the photosensitive drum (32). The photoreceptor drum (32) is connected to the developing roller (
81) with a gap of about 2 [m], while the gap with the tip of the covering cover (71) and the frame t, (7o
) is provided at the tip of the member (116) for preventing scattering of the developer and the gap is approximately 0.3 (nwn).Furthermore, (117) is a protective cover made of plastic, and the negative side is covered. It is inserted into the slit (74) formed in the cover (71), and the other side is inserted into the frame (70).
) is formed on the top of the first guide (70a).
- (70c), and is worn when the unit (31) is transported 11ν and when attached to and detached from the main body, but is removed after the unit (31) is attached. Also, (118a).

(118b) is inserted from the side frame (82b) on the non-1ψ moving side of the unit (31) and is used to transfer developer during transportation.
It is a pin for sealing inside the unit 1-(:11) and is removed after attaching the unit 1-(:11) to the main body (10). Furthermore (121a), (121
b) and (121, c) are holes into which a pin (not shown) on the main body side is inserted in order to position the unit (31) within the main body (10).

Next, we will discuss the operation. When the power switch (21) of the main body (10) is turned on, the control section (55) controls the main body (10) while rotating the drive source (not shown) for a certain period of time.
The condition of each part is checked, and if any abnormality is found, a warning lamp (not shown) on the control panel (27) is lit to notify the operator. - When there is no six-person state, the control unit (55) controls the heater (50a) built in the heat roller (50) of the fixing device (5z) so that the temperature detected by the thermistor (50b) is 22° [ ℃] until the temperature of the roller (5o) is 220℃.
('C), the heater (50a) is turned on, and when the temperature of the heat roller (50) drops to 180C'C], the heater (50a) is turned on again, and the temperature of the heat roller (50) is turned on again. The heater (50a) blinks repeatedly to maintain the temperature between 180 ("C) and 220 [°C], while displaying on the control panel (27) that printing preparation is complete and waiting for printing. At the same time, the information is transmitted to the host system 11 (not shown).

In this state, when a command to start printing is sent from the host system (not shown) and printing is started, the control unit (5
5) first operates a mirror motor drive circuit (not shown) to rotate the mirror motor (61). When the polygon mirror (62) stabilizes at a constant rotation speed of 6000 (7 minutes of rotation), the mirror motor drive circuit (not shown) transmits this to the control section (55). ) operates a main motor driving circuit (not shown), rotates the main motor (not shown), and rotates the drive shaft (114) to rotate the photoreceptor drum (32).
), and also rotates other rollers such as the developing roller (81). At the same time, the control section (55) operates the charging device (33), the static eliminating device (37), and the like. As a result, the photoreceptor drum L, (32) rotates in the direction of the arrow S, and first, the surface potential is increased to 6 by the charging device (33).
It is uniformly negatively charged to 00 [V].

On the other hand, in the laser optical system (34), a laser beam (60a) oscillated from a laser diode (60) based on print data from a host system (not shown) is collected by a collimator lens and a compressor lens (not shown). After the light is emitted, it is incident on a polygon mirror (62) that is stably rotated at 6000 [rotation time: 7 minutes] so as to be scanned in the longitudinal direction of the photoreceptor drum (32). The laser beam (60a) reflected by the polygon mirror (62) is
The photoreceptor drum (32), which is uniformly charged to approximately β0O (V), is irradiated through the lens system (63).
32)" - an electrostatic latent image is formed. However, in the lens system (63), the laser beam (60a) from the polygon mirror (62) is focused into a spot of about several tens of microns and irradiated onto the photosensitive drum (32). Thereafter, the photosensitive drum (32) carrying the electrostatic latent image reaches the developing device (36) as it rotates, and the developing device (36) is developed and cleaned in the following manner.

That is, in the developer container (93), the first spiral (100) is connected to the gear (104) and the second gear (106) to which the drive from the main motor (not shown) is transmitted.
and the second spiral (101) are rotated in the direction of the arrow and the direction of the arrow U, respectively, and the third gear (10
The aluminum sleeve (83) is rotated by the first gear (91) by the gear (104) through the arrow V
rotated in the direction. Then, new 1-toner is supplied onto the second spiral (lot) in the developer container (93) from the toner hopper (79) through the supply port (78), and is first developed by the second spiral (101). The developer is transported in the direction of arrow W in the developer container (93) while being sufficiently stirred with the developer,
Furthermore, the sufficiently stirred developer is passed through the first spiral (100
), the developing roller (81
) side to form a magnetic brush on the aluminum 11 sleeve (83). Furthermore, aluminum sleeve (
83), the band 1? ! It has the same polarity as the voltage and is about 400 (V
) is applied. When the electrostatic latent image on the photoreceptor drum (32) reaches the developing device (36), the toner is of negative polarity in the non-exposed area where the surface potential (-) 600 (V) is maintained. , since the surface potential is greater than the bias potential (-) 400 [V], there is no movement of toner from the developing roller (81) to the photosensitive drum (32) and development is not carried out.However, there is residual toner in this non-exposed area. If the surface potential (-) is 600 (V
) and bias potential (-') of 400 [V], the residual toner is collected on the developing roller (81) side and the photosensitive drum (32) is cleaned. On the other hand, in the exposure area where the surface potential on the photoreceptor drum 1% (32) is approximately 0 [V], the developing roller (81) to which a bias voltage is applied is
), the toner is transferred to the developing roller (81).
The image is then transferred to the photoreceptor drum (32) and developed. Thereafter, as the photosensitive drum (32) rotates, the entire surface of the photosensitive drum (32) is exposed to light by the irradiation lamp device (76), and after being neutralized, it reaches the transfer device (37). On the other hand, in the paper feed section (24), after the main motor (not shown) is driven, the control section (5
The paper feed roller (40) is rotated once in response to the paper feed signal from the paper feed cassette (23).
1) is taken out. And the sheet paper (41) is the first
sheet paper guide (42a).

(42b), the first lever (44b) is actuated to turn the first reed switch (44c) from on to off, and the first paper detection device (44) sends the sheet paper (44b) to the control unit (55). ) displays that it has arrived, then it reaches the stopped aligning rollers (43a) and (43b) and is temporarily stopped. Thereafter, the control unit (55) moves the aligning rollers (43a), (43
b) starts driving the second sheet paper guide (46),
The sheet paper (41) is conveyed to the transfer device (37) via intermediate rollers (47a) and (47b). When the developing section of the photoreceptor drum (32) and the sheet paper (41) reach the transfer device (37), a positive charge of opposite polarity to the toner is applied by the transfer device (37), and the photoreceptor drum (32)
) is transferred to a sheet of paper (41). Next, the sheet paper (41) is peeled off from the photoreceptor drum (32), passes through the third sheet paper guide (48), and passes through the fixing device (52).
), but the photoreceptor drum (32) has a diameter of approximately 30 (n
Since the sheet paper (41) is small in size (u), the sheet paper (41) is naturally peeled off from the photoreceptor drum (32) only by its stiffness without using a peeling device such as a peeling claw or a peeling charger. The sheet paper (41) is fixed by a fixing device (52) in which the surface temperature of the heat roller (50) is maintained between 180 ['C] and 220 [C], and then the second lever (54b) ) and turn on the second reed switch (54c).
from on to off, the second paper detection device (54) displays on the control unit (55) that sheet 1 - paper (41) has arrived, and the paper is ejected by the paper ejection rollers (53a), , (53b). The paper is delivered onto the paper tray (26). When the sheet paper (41) completely passes through the second paper detection device (54), the second reed switch (54c) is turned back on from the off state, and the control unit (55) detects the sheet paper ( 4
1) Displays that the paper has been ejected. Also, during this time, the photosensitive drum (32) that has passed through the transfer device (37) is entirely exposed to light by a static elimination lamp (38) to remove residual charges.
The next print is enabled.

When all the printing processes are completed in this way, the control section (5
5) stops other devices except for temperature control of the heat roller (50) and waits for the start of the next printing, after which printing starts sequentially in response to printing commands from the host system (not shown). The process will have to be repeated. During this time, the control unit (55) stores the identification number of the unit (31) based on the binary pattern on the sticker (108) read by a photoelectric sensor (not shown), and also stores the identification number of the unit (31) every time the printing process is completed. The number of printed sheets is sequentially added to the number of printed sheets from the start of use of the unit (31). When the number of printed sheets reaches 2, which is the preset number of sheets to be printed, the control section (55) notifies the control panel (27) to that effect.
). This allows the operator to
) has exceeded its usage limit, and in order to replace it with a new unit, first open the right center cover (16) of the main body (10) and remove the first guide (70a) and second guide. Pull out the frame (70) along (70b),
Take out the used unit (31). At this time, on the drive side of the unit, the gear (104) meshes with the gear on the main body side (not shown), and the photoreceptor drum (3
2) is a leaf spring (111) and a spring clutch (11).
2) is fitted to the drive shaft (114) through
Drive shaft (114) of spring clutch (112)
) in the axial direction is only the frictional force corresponding to the tightness of the spring, so it only resists the pressing force of the leaf spring (111) and the frictional force of the spring clutch (112), and the photoreceptor drum (32) Furthermore, the unit (3
1) can be inserted and removed from the drive shaft (114) relatively easily. Next, the operator uses the photoreceptor drum (
A new unit (31) is installed into the main body (10) with the exposed part of the unit (32) still covered by the protective cover (117). At this time, the handle (72) used for transportation is ) in the recess.

Then, the first guide (70a) and the second guide (70
b) into the rails (10a) and (10b) inside the main body (10).
) and insert the drive shaft (114) into the flange of the photoreceptor drum (32),
The pin (not shown) on the main body side is inserted into the hole (121a), (12
1b) and (121c), and further so that the power supply blade (88) comes into contact with the conductive shaft (85).
The unit (31) is attached to the main body (1o). Further, the operator operates the slit (70c).

(74) and pull it out to the outside of the main body (lO) through the opening of the right small cover (16) to open the photosensitive drum (32) and make it ready for use. The bottles (118a) and (118b) for preventing scattering of (102) are also removed, and the unit (
31) into a usable state, close the right small cover (16), and resume printing. Also, after this, the main motor (
When the gear (104) is rotated by the drive of the gear (104), the cylindrical portion (
The binary pattern on the sticker (10g) affixed to the unit 104a) is read, and the new identification number of the newly installed unit (31) is stored in the control section (55). In the control unit, the number of printed sheets for each recognition number is stored in sequence according to the printing. For example, even if a unit that has already reached the end of its lifespan is accidentally reinstalled into the main unit, it will be recognized immediately. When the number is read, the control unit (55)
The unit prints the number of sheets that have reached the end of its life, recognizes that the unit has been used, and displays this on the control panel (27). In addition, the protective cover (117
) is saved so that it can be reattached to the unit (31) when the unit (31) is attached or detached during maintenance.

If the spiral is formed like this, the diameter of the second spiral (101) in the developer container (93) is larger than the diameter of the first spiral (100), and the second blade (101a) is half cut out. Because it is made up of multiple long circular plates,
The conveying force of the developer (102) is the first spiral (1
00) and the second spiral are made equal to each other, the developer (102) is uniformly conveyed within the developer container (93), and the developer (102) is stably supplied to the developing roller (81). On the other hand, the second spiral (101)
It has a larger agitation force than the first spiral (100), and can sufficiently mix the toner supplied from the toner hopper (80) through the supply port (78) with the developer already in the developer container (93). Since stirring is possible, the toner concentration of the developer supplied to the developing roller (81) can be made uniform, and as a result, stable image density can be obtained, and the image quality can be improved.

It should be noted that the present invention is not limited to the above-mentioned embodiments, but can be modified in various ways. For example, the number of sheets to be used in the life of the unit, the charging position of the image carrier, the magnitude and polarity of the developing bias of the developing roller, etc. can be changed arbitrarily. The diameter of the spiral is also not limited as long as the diameter of the second spiral is larger than the diameter of the first spiral.

Furthermore, the shape of the spiral blades can be arbitrary, and the blades of the second spiral may also be in the form of a continuous spiral like the first spiral, but in this case, the amount of developer conveyed by the first spiral and the second spiral can be changed. In order to achieve uniformity, the second spiral may be equipped with blades in the opposite direction to prevent the developer from being conveyed.Also, the device for identifying each unit may be a photoelectric sensor. It is not a device for reading patterns, but a value of about several [Ω] to several (MΩ) is attached to the end of the covering cover (127) of the unit (126) as in the other modification shown in Fig. 14. While different resistance elements (128) are installed, on the main body side, when the unit (126) is installed, the resistance element (12g)
A resistance measuring device V! is connected to the connector terminal (128a) of V! and reads the resistance value as a voltage. 1 (not shown).

A device may be used in which the measurement results obtained by this resistance measuring device (not shown) are stored in a control section (not shown) and the number of images for each unit is counted.

Furthermore, when the printing capacity of the unit reaches its lifespan, the image formation may be immediately stopped.
In the embodiment, the developing device performs development and cleaning at the same time, but the present invention is not limited to this, and may be a device that performs only development.

〔Effect of the invention〕

As explained above, according to the present invention, by making the diameter of the second spiral larger than that of the first spiral, the developer is sufficiently stirred and the toner concentration is made uniform, and then the developing roller Since the developer can be supplied to the image forming apparatus, it is possible to eliminate the uneven density of the developer caused by insufficient stirring as in the prior art, to obtain a uniform image density, and to improve the image quality.

[Brief explanation of the drawing]

Figures 1 to 13 show one embodiment of the present invention; Figure 1 is an external perspective view of the main body from the front, Figure 2 is an external perspective view of the main body from the rear, and Figure 3 is the main body. Figure 4 shows the unit, A) is a schematic explanatory diagram of the inside, (B) is a partially enlarged view of (A), Figure 4 is a perspective view of the unit, and (B) is a perspective view of the cover. A perspective view showing the frame, FIG. 5 is a partial sectional view showing the developing roller and its power supply blade, FIG. 6 is a sectional view showing the unit and the rail of the main body, and FIG. 7 shows the first spiral. FIG. 8 is a partially omitted side view showing the second spiral, FIG. 9 is a schematic explanatory diagram showing the circulation of the developer in the developer container, and FIG. 10 (A) is a partially omitted side view. A schematic sectional view showing the drive side end of the photosensitive drum, FIG. 10(B) is a sectional view showing the drive transmission section, FIG. 11 is a side view showing the non-drive side of the unit, and FIG. FIG. 13 is a perspective view showing the protective cover, FIG. 13 is a side view showing a pin that seals the inside of the developer container, FIG. 14 is a perspective view showing another modification, and FIG. 15 is a perspective view showing a conventional device. be. 10... Main body, 23... Paper feed cassette, 26... Paper output tray, 31...
・Unit, 32...Photosensitive drum, 33・
...Charging device. 34...Laser optical system, 36...Developing device. 37... Transfer device, 38... Static elimination lamp, 41-... Sheet paper, 47a,
47b-Intermediate roller, 52... Fixing device, 55...
-Control unit, 70...Frame, 71...Coating cover, 71a...Rib, 72...Handle, 76...Irradiation lamp, 81...
Developing roller, 83... Aluminum sleeve, 84...
... Magnet roller, 85... Conductive shaft,
88... Power supply blade, 92... Doctor blade, 93... Developer container, 94... Screw,
100...first spiral. 101... Second spiral, 103... Partition wall, 1
04...Gear, 104a...Cylindrical portion, 108...Seal, 110...
Flange, 111... Leaf spring, 112
... Spring clutch, 114 ... Drive shaft, 117 ... Protective cover, agent patent attorney
Inoue - younger brother 1 Figure 2 Figure 5 Figure 7 Figure 8 Figure 9 (A2 Figure 1O Figure 13 Figure 15

Claims (1)

[Scope of Claims] 1. After the developer is stirred and conveyed in the developer container by a first spiral and a second spiral arranged in parallel with the first spiral, the developer is stirred and conveyed by a developing roller. 1. A developing device for applying a latent image on an image carrier, wherein the diameter of the second spiral is larger than the diameter of the first spiral. 2. The developing device according to claim 1, wherein the first spiral and the second spiral are parallel to the developing roller. 3. In the developing container, the first spiral is placed adjacent to the developing roller, and new developer is supplied to the second spiral side.
Developing device according to any one of paragraphs. 4. The first spiral is connected to the first shaft and this first spiral.
a continuous spiral-shaped blade attached to a shaft, the second spiral includes a second shaft, a partially cut-out oval-shaped blade attached to the second shaft; A developing device according to any one of claims 1 to 3, characterized by comprising: 5. The developing device according to any one of claims 1 to 4, wherein the developing container is supported by the same unit that supports the image carrier.