JPH01108565A - Developing device - Google Patents

Abstract

PURPOSE:To obtain an image having a good quality by providing a means for giving a vibration to a frame by following up the movement of a developing part. CONSTITUTION:When a developing part is switched from a first state to a second state, or on the contrary, switched from the second state to the first state, in that case, the vibration is given to the upper frame 35 and the lower frame 36, respectively by a vibrating means 47. Subsequently, a developer stuck to the frames 35, 36 is peeled off from the frames 35, 36, taken into the developer held on the surface of a developing roller 33 and collected. In such a way, such problems as a toner stuck to the frames 35, 36 is mixed into a toner, an image is brought to color mixture and a picture quality failure is caused are settled.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a developing device used in an image forming apparatus using an electrophotographic copying process, such as a copying machine or a printer.

(Prior Art and its Problems) Conventionally, as one of the aforementioned developing devices, there is one proposed by the present applicant in Japanese Patent Application No. 122850/1982.

This developing device includes a developing section in which the upper and lower parts of a developing roller facing the electrostatic latent image carrier are covered with a frame, and a toner hopper having a toner supply roller facing the developing roller in an opening of the main body. and in this one,
The toner contained in the toner hopper is supplied to the surface of the developing roller via the toner supply roller, where the toner and carrier are mixed and stirred to prepare a two-component developer.

Further, in this type of developing device, by replacing the toner hopper with a toner hopper containing toner of a different color from the toner contained therein, the electrostatic latent image carrier is formed on the surface of the electrostatic latent image carrier. Images can be visualized in different colors.

(Problem to be Solved by the Invention) However, in the above-mentioned developing device, when the toner and carrier are mixed and stirred at the outer circumference of the developing roller, the poorly charged toner flies up in the form of powder smoke, which spreads to the inner surface of the frame. It adheres electrostatically and mechanically to the surface. Although it is possible to partially scrape off the adhered toner by rubbing the developer held on the outer periphery of the developing roller, it cannot be completely removed.

Therefore, when the toner hopper is replaced and toner of a different color is supplied to the surface of the developing roller, the toner adhering to the frame is mixed into the toner, resulting in a problem of color mixing in the image and poor image quality. It had a point.

(Means for Solving the Problems) The present invention has been made to solve the above problems, and will be described with reference to FIG. 2.6 showing one embodiment. The device (5) includes a developer supply roller (
63) and (73), and a plurality of developer supply means (toner hoppers) arranged on the side of the electrostatic latent image carrier (3).
60), (70), and the developer supply rollers (63), (70) move along the outer periphery of the electrostatic latent image carrier (3).
3) a developing roller (32) selectively supplied with a developer via a developing roller (32) and at least partially covered with a frame (36) for supplying the developer to the surface of the electrostatic latent image carrier; A vibration means (47) is provided for applying vibration to the frame (36) as the developing part (3o) moves.

(Function) In the developing device (5), as shown in FIG. 2, the developing section (30) faces the developer supply rollers (63) and (73) of the developer supply means (60) and (70). In the state [1.2 state] (p + ), (p 2), the developing section (30) supplies the developer supply means (60) via the developer supply rollers (63), (73). , (70), and the electrostatic latent image on the electrostatic latent image carrier (3) is visualized using this developer.

Further, as shown in FIG. 6, the developing section (30) can be changed from the first state to the second state, or vice versa.
When the state is switched to the above state, the vibration means (47) applies vibrations to the upper frame (35) and the lower frame (36), respectively. And frames (35), (3
The developer attached to the roller 6) is peeled off from the frames (35) and (36), taken in and collected by the developer held on the surface of the developing roller (3=3-3).

(Example) Hereinafter, the present invention will be described with reference to the accompanying drawings showing one example thereof.

A. General Structure and Operation of Copying Machine FIG. 1 is a sectional view of a small-sized copying machine equipped with a developing device according to the present invention, and its structure will be explained together with its operation.

Approximately in the center of the copying machine body (1), there is an electrostatic capacitor whose surface is evaporated or coated with selenium, zinc oxide, cadmium sulfide, or other organic photoconductors. A photosensitive drum (3) serving as a latent image carrier is arranged.

This photosensitive drum (3) is rotated in the direction of arrow (a) by the main motor (2) driven by the ON operation of a print switch (not shown), and the surface is heated to a predetermined level by the discharge of the electrostatic charger (4). charged to a potential.

In the optical system (8), an exposure lamp (9) is turned on, and the light is irradiated onto a document (not shown) placed on a document table (14) that scans in the direction of arrow (b), and the reflected light is The photoreceptor drum (3), which is charged to a predetermined potential as described above, is exposed to light from the exposure point (xl) through the Selfox lens array (12), and the original image is formed on the surface of the photoreceptor drum (3). An electrostatic latent image corresponding to the image is formed.

This electrostatic latent image is supplied with toner at a portion (X2) facing the developing device (5) and is visualized as a toner image. Note that this developing operation will be explained in detail later.

The copy paper (S) is fed from the paper feed section (2o) to the paper feed roller (2I).
is fed one by one based on the rotation of the guide plate (22X
23), waits in front of the timing roller pair (24), and moves the transfer area (
X3), and the toner image is electrostatically transferred based on the discharge of the transfer charger (6).

The copy paper (S) onto which the toner image has been transferred is placed on the photosensitive drum (
After being separated from the surface of the copy paper (S), the toner image is transported by a transport belt (25) via a guide plate (26) to a fixing device (27), where the toner image is fused and fixed onto the copy paper (S). The paper is discharged onto the paper discharge tray (28).

The cleaning device (7) removes residual toner from the surface of the photosensitive drum (3) that has passed through the transfer area (X3), and then the light from the exposure lamp (9) passes through the opening (10) of the reflective shade (10). 11) and a mirror (13) to irradiate the region (X4) to remove residual charges.

B. Construction of the developing device (5) Next, the structure of the developing device (5) according to the present invention will be explained in the following order with reference to FIGS. 2 to 15.

1. Schematic configuration of developing device (5) ii. Developing section (30) iii. Switching mechanism (41) iv. Vibration mechanism (47) ■. Toner hopper (60X70) vi. Opening/closing mechanism (80) vii. Gap adjustment mechanism ( 90) vii,
Lock mechanism (100) ix, Drive mechanism (120) , a first toner hopper (60) that accommodates black toner, a second toner hopper (70) that accommodates color toner other than black (for example, red toner), and an arrow mark along the outer peripheral surface of the photoreceptor drum (3). (c) and (c'), selectively receives toner from the toner hopper (60) or (70), and transfers it to the electrostatic latent image formed on the surface of the photoreceptor drum (3). The developer 1 (30) is supplied to the developer 1 (30).

ii, Developing section (30X see Figure 3.4) Developing section (30)
, the developing frames (31), (31) (one not shown) are rotatably attached to the back side and the front side of the photosensitive drum support shaft (16).

The developing frames (31), (31) are equipped with a developing roller (32).
) is supported by a method described later, and a predetermined gap is formed between the developing roller (32) and the photosensitive drum (3).

Note that the developing roller (32) has an outer diameter of φ16, for example.
+ An insulating or semi-insulating material, or one in which an organic polymer film is plasma-polymerized on the surface of an aluminum cylinder by glow discharge in a vacuum is used.

A magnetic roller (33) in which a plurality of magnets with magnetic poles extending in the axial direction are arranged in the circumferential direction is housed inside the developing roller (32), and one end of the spindle is attached to the developing roller (32).
The other end (34) of the spindle protrudes from the developing roller (32) and is fixed to the developing frame (31).
(see figure), and is fixed in a non-rotatable state relative to the developing frame (31). On the other hand, the developing roller (3
2) has one end rotatably supported by the developing frame (31) and the other end rotatably supported by the spindle of the magnetic roller (33).

Therefore, even if the developing section (30) moves along the outer peripheral surface of the photoreceptor drum (3), the magnetic pole of the magnetic roller (33) maintains a constant positional relationship relative to the photoreceptor drum (3). be. That is, the magnetic pole facing the photosensitive drum (3) always faces the photosensitive drum (3).

Also, between the developing frames (31), there is an upper frame (31) that covers the upper and lower parts of the developing roller (32), respectively.
35) and the lower frame (36), and only the portion of the developing roller (32) facing the photosensitive drum (3) and the opposite side thereof are open. The lower frame (36)
A stirring chamber (38) is formed along the axial direction on the surface facing the developing roller (32), and the inner surface of the stirring chamber (38) is a curved surface that allows the developer to flow smoothly without stagnation. The counterclockwise side wall of the stirring chamber (3B) has a regulating portion (
39) Toshishita.

Further, a developing section (30) is provided above and below the developing section (30), respectively.
The switches (Sl) and (S2) that detect this are installed.

As shown in Fig. 3, the developing section (30) having the above configuration is provided with the photosensitive drum (3), the charger (4), and the cleaning device (7) at the rear and front sides of these. The entire imaging unit (
The imaging unit (IU) is configured to be detachable from the copying machine main body (1).

Further, the developing section (30) is provided with a switching mechanism (41), a vibration mechanism (47), etc., and these will be explained below.

111, Switching mechanism (see 41X Figure 4.5) Switching mechanism (
41) moves the developing section (30) along the outer circumferential surface of the photosensitive drum (3) and switches between a blackboard image state (Pl) and a color developing state (P2).

In this switching mechanism (41), a switching lever (42) is fixed to the developing frame (31) of the developing section (30),
A toner hopper (60) is attached to the switching lever (42).

A plate (43) located on the top surface of (70) is a lock. Further, a window (44) is formed in the plate (43), and the lever (42) is rotated in the direction of arrow (c).
When switching to the blackboard image state (Pl) in which the developing roller (32) faces the supply roller (63) of the first toner hopper (60), the window (44) shows the black mark provided on the top surface of the toner hopper (60). (45) appears.

Conversely, by rotating the lever (42) in the direction of the arrow (C'), the developing roller (32) moves along an arc (Ll) with its center centered on the photoreceptor drum (3),
When switching to the color development state (P2) in which the developing roller (32) faces the supply roller (73) of the second toner hopper (70), the toner hopper (70) is placed in the window (44).
) so that the color mark (46) provided on the top surface appears.

Then, a black mark (45) or a color mark (46) appears through the window (44) on a display section (not shown) provided on the copying machine main body (]), and whether the copy is a concrete development or a color development copy is displayed. Displays whether it is possible.

iv. Vibration mechanism (see 47X Figure 6) The vibration mechanism (47) uses the switching mechanism (4I) to switch the developing section (30) between the blackboard image state (Pl) and the color development state (Pl).
P2) and the upper and lower frames (3).
5) and (36), thereby peeling off toner mechanically or electrically adhered to the inner surface of the frame.

This vibration mechanism (47) includes a spring vibrator (48),
(52) are each provided with a striking portion (50) on the photoreceptor drum (3) side.
), (54), is swingably supported by the upper frame (35) and lower frame (36) via the fulcrums (4, 9), (53), and is supported by the springs (51), (55). It is biased in one direction. In addition, the frame (57) installed in the copying machine body (1) has an uneven portion (56) continuously formed on an arc centered on the support shaft (16) of the photoreceptor drum (3). There is a vibrator (48) there.

The outer end of (52) is engaged.

Therefore, when the lever (42) of the switching mechanism (41) is held to switch the developing section (30) from the blackboard image state (Pl) to the color one development state (P2) or vice versa, the vibrator ( The end portions of 48) and (52) repeatedly engage and disengage from the uneven portion (56), causing the vibrators (48) and (52) to vibrate, thereby causing the striking portions (50) and (54) to vibrate, respectively. The outer parts of the upper frame (35) and lower frame (36) are struck to give them vibration.

v. Toner hoppers (60), (70X, see FIG. 7) The toner hoppers (60), (70) supply black toner and color toner, respectively, to the developing section (30).

These toner hoppers (60) and (70) are connected to the developing section (30).
) is removably located at the rear of the toner hopper (
At the front of the main bodies (61) and (71) of 60) and (70), there are supply rollers (63) in the openings (62) and (72).

(73) are arranged, and the respective supporting shafts (68), (78) are provided in the main bodies (61), (71) with bearings (94), (95).
(see Figure 10). Also,
The centers of the supply rollers (63), (73) are located in an arc (L2)J- centered on the photoreceptor drum (3), and the supply rollers (63), (73), ! : Photoreceptor drum (
3), and the distance therebetween is slightly larger than the outer diameter of the developing roller (32).

The supply rollers (63) and (73) have, for example, an outer diameter of φ16, and have a depth of 10 to 200μ by blasting, etching, or knurling on the outer peripheral surface.
A cylindrical body made of conductive, non-magnetic aluminum or the like is used, and has a micro-concave portion of π formed therein.

Openings (62) of toner hopper bodies (61), (71)
, (72) are provided with regulating blades (64), (74) and toner outflow prevention films (65), (75).
These tips are pressed against the rear outer peripheral surface of the supply roller (631 (73)).

The rear portions of the toner hoppers (60) and (70) are provided with the supply rollers (63) and (73), and the regulation blades (64) and (7).
4) and toner outflow prevention films (65) and (75) to form toner storage tanks (66) and (76), respectively, and toner storage tanks (6) of the first toner hopper (60).
6) rotatably accommodates a stirring blade (67).

Note that the switches (S3) and (S4) are switches that detect whether or not the toner hoppers (60) and (70) are installed at predetermined positions, respectively, and the signals thereof are outputted to a control device (not shown). It has become.

vi, opening/closing mechanism (see 80X Figure 7.8) opening/closing mechanism (80X)
0) is the opening (6) of the toner hopper (60), (70).
2) and (72) are opened and closed to cut off the supply of toner from unused toner hoppers and prevent toner from falling.

This opening/closing mechanism (80) includes a supply roller support shaft (68),
Frame (81X81) on both ends of (78), (85) (
85) is rotatably supported, and the frame (85) is rotatably supported.
1881) and (85X85) have opening/closing covers (82
), (86) are bridged.

The frames (81) and (85) are each integrally provided with segment gears (83) and (87), and are moved in the closing direction [arrow (d)] by springs (84) and (88).

(e) direction)]. The springs (84), (88) are wound around the support shafts (68), (78), one end is locked to the main body (61), (71), and the other end is connected to the frame (81), ( 85) respectively.

On the other hand, a segment gear (89) is integrally provided in the developing frame (31) of the developing section (30), and this segment gear (89) is connected to the segment gear (83) of the toner hopper (60), (70), (87) meshes with the developing section (
30) in the black development state (Pl) or color development state (P2).
), either one of the openings (62) or (72) is opened.

More specifically, when holding the lever (42) of the switching mechanism (4I) and rotating the developing section (30) and segment gear (89) in the direction of arrow (c) to set the black developing state (PI), ( solid line state in Fig. 8), the segment gear (89)
segment gear (83) as it moves.

(87) rotate in the directions of arrows (d') and (e), respectively, and as shown in FIG.
The opening/closing cover (82) of the second toner hopper (70) is retracted to open the opening (62) of the second toner hopper (70).
) is closed with an opening/closing cover (86).

When holding the lever (42) and rotating the developing section (30) and the segment gear (89) in the direction of the arrow (Co) to set the color developing state (P2) (the state shown by the two-dot chain line in Fig. 8),
Segment gears (83) and (87) are respectively indicated by arrows (d)
, (e') direction, and the first toner hopper (6
The opening (62) of the second toner hopper (70) is closed by the opening/closing cover (82), and the opening/closing cover (86) of the second toner hopper (70) is retracted to open the opening (72).

vii. Gap adjustment mechanism (90X, see Figure 9.10) The gap adjustment mechanism (90) adjusts the distance (gap) between the developing roller (32) and the supply rollers (63) and (73) facing it to a predetermined value. This is the value to be set.

In this gap adjustment mechanism (90), the developing roller (32
) has gap adjustment rollers (91) on both ends of the support shaft (33).
is rotatably provided. In addition, the supply roller support shaft (68
), (78) have gap adjustment rollers (92) at both ends, respectively.
, (93) are rotatably provided.

On the other hand, the supply roller bearings (94) and (95) formed on the side walls of the toner hopper bodies (61) and (71) have a slightly larger diameter than the supply roller support shafts (68) and (78). A gap is formed between (68), (78) and the bearing (94), (95).

Further, stoppers (96), (97) are formed on the side walls of the toner hopper bodies (61), (7), and between the stoppers (96), (97) and the support shafts (68), (78). springs (98) and (99) are interposed, and the support shaft (
68) and (78) are biased toward the developing section (30) in the direction of the arrow.

According to the gap adjustment mechanism (90) having the above configuration, as shown in FIG. 9, when the developing roller (32) is in the black development state (Pl), the gap adjustment roller (91) is Gap adjustment roller (92) of toner hopper (60)
) are pressed into contact with each other, and the developing roller (32) and the supply roller (63
) A predetermined gap is set between the two.

When the developing roller (32) is switched to the color developing state (P2), the gap adjustment roller (91) of the developing roller (32)
) is the second toner hopper (70) gap adjustment roller (
93), and the developing roller (32) and supply roller (
73), a predetermined gap is set between the two.

vii. The lock mechanism (+00) locks the first toner hopper (60) when the developing section (30) is in the black developing state (PI), and the color When in the developing state (P2), the second toner hopper (70) is locked.

In this locking mechanism (100), the developing frame (31)
Lock release parts (I01) and (IO2) are provided on the outer surface of the release part (101), and the surface of the release part (101) [the surface facing the stopper (103) described below] rises in the direction of arrow (c). The surface of the release portion (IO2) [the surface facing the stopper (104)] slopes upward in the direction of arrow (C').

On the other hand, the copy machine body (1)? Is this Figure 12.13? As shown, stoppers (lO3) and (104) are provided on the sides of the toner hoppers (60) and (70), and the rear portions of the toner hoppers (I05) and (+06) are connected to each other through fixing members (I05) and (+06). is fixed to the copying machine main body (1), and the stopper (103
), (104) have engaging holes (107), (1
08) are respectively formed. Also, a toner hopper (60
), (70) have the engaging holes (I07) coaxially with the supply rollers (63), (73).
), (1OS> and the engagement protrusion (+09) with approximately the same diameter as
10') is formed.

In the lock mechanism (+00) having the above configuration, the 11th
As shown in the figure, the developing frame (31
) is set to the black development state (Pl), the release section (
+02) slips into the tip of the stopper (+04), the engagement hole (108) of the stopper (104) is disengaged from the engagement protrusion ( ] ] O) of the second toner hopper (70), and the toner hopper ( 70) is removable (see FIG. 13). On the other hand, as shown in FIG. 12, the stopper (103) of the first toner indicator flange (60) is in pressure contact with the side surface of the developing frame (31), and the engagement hole (+07) is in contact with the engagement protrusion. (109) and engages with the first toner hopper (6).
0) is locked in a non-removable state.

Hold the lever (42) of the switching mechanism (41) and turn on the developing section (3).
0) to the color development state (P2), the release part (101) sinks into the surface facing the stopper (103) and the first toner hopper (60) is set in a removable state, contrary to the above. and the release part (102) is pressed against the stopper (
The second toner hopper (7) is evacuated from the opposite part of the
0) is locked.

That is, when the developing section (30) is in the black developing state (Pl), the first
The second toner hopper (60) is locked and cannot be taken out, and only the second toner hopper (70) is set to be removable. Conversely, the developing section (30) is in a color developing state (
At the time of P2), the second toner hopper (70) cannot be taken out, and only the first toner hopper (60) is set to be removable.

ix, drive mechanism (1200 see Figure 14.15) In the drive mechanism (+20), the support shaft (1) of the photoreceptor drum (3)
The photosensitive drum drive gear (121) provided in 6) is drivingly connected to the main motor (2) (see Figure 1), and the developing roller drive gear (122) attached to the spindle of the developing roller (32). is adapted to rotate around the photoreceptor drum drive gear (12+) while meshing with it via the developing frame (31), and these gears (+21) and (+2
2) constitutes a differential gear device.

Also, the support shaft (68) of the supply rollers (63) and (73).

Supply roller drive gears (+24) and (126) are attached to (78) via a supply roller drive clutch (the clutch corresponding to supply roller (73) 127X is not shown), and these supply roller drive gears (+24) and (126) are attached to Gear (124), (
126) are idler gears (123) and (125), respectively.
It meshes with the.

Further, although not shown, the stirring blade (67) provided in the first toner hopper (60) is connected to the supply roller drive gear (12).
4) so as to rotate together with the supply roller (63). Note that the stirring blade (67) may be connected to the drive system of the document table (14) so that it rotates as the document table moves.

In the drive mechanism (120) having the above configuration, the developing section (
30) is set to the black development state (PI), as shown in FIG. It meshes with gear (+23).

Therefore, when the main motor (2) is driven in this state and the photosensitive drum drive gear (+21) rotates in the direction of the arrow, the developing roller drive gear (122), idler gear (123), and supply roller drive gear ( 124)
rotate in the directions of the arrows, and the photosensitive drum (3) and the developing roller (32) rotate in the directions of the arrows, respectively. Further, when the supply roller drive clutch (127) is turned on by a signal from a control device (not shown), the supply roller drive gear (127) is turned on.
24,) is transmitted to the supply roller (63).

When the developing section (30) is switched from the black developing state (Pl) to the color developing state (P2), the developing roller drive gear (12
2) moves along the circumference of the photosensitive drum drive gear (121) while meshing with it, and meshes with the idler gear (125) of the second toner hopper (70).

Therefore, when the main motor (2) is driven in this state and the photosensitive drum drive gear (121) rotates in the direction of the arrow, the developing roller drive gear (122), idler gear (125), and supply roller drive gear are rotated accordingly. (126
) rotate in the directions of the arrows, and the photosensitive drum (3) and the developing roller (32) rotate in the directions of the arrows, respectively. Furthermore, when the supply roller drive clutch (not shown) is turned on, the rotation of the supply roller drive gear (+26) is controlled to the supply roller (73).
transmitted to.

y, toner density control means (see Figure 2), then the developing section (
30) The density adjustment means for the toner supplied will be explained.

A developing bias voltage (vb) is applied to the developing roller (32) of the developing section (30), and the supply rollers (63) and (73)
) has a DC bias (Vss) and an AC bias (Vrm
A recovery bias voltage (Vs) is applied by connecting the voltages S) in series, and the bias voltages (Vb) and (Vss) are variable, and by adjusting the voltage value, the toner concentration on the developing roller (32) can be adjusted. It is adjustable.

xi, developer In the developing device (5) having the above configuration, a two-component developer consisting of toner and carrier is used.

As the carrier, a binder type carrier having a particle size of about 20 to 100 μm, a ferrite carrier, an iron powder carrier, or a carrier whose surface is overcoated with an appropriate resin is used, and the carrier is a developing roller (32).
The magnetic roller (33) is magnetically held on the outer peripheral portion of the magnetic roller (33).

The toner used is a toner having a particle size of 5 to 30μ and manufactured by a pulverization method or a suspension polymerization method, or a capsule toner.As mentioned above, the first toner hopper (60) contains black toner. The second toner hopper (70) contains color toner (for example, red toner) other than the fish toner.
is accommodated.

C1 Black Developing Operation The concrete developing operation using black toner in the first toner hopper (60) will be described below.

The developing section (30) is set to the black developing state (PI) by the switching mechanism (41), and a black mark (see 45X Fig. 4) is displayed on the display section (not shown) of the copying machine main body (1). is displayed, the developing roller (32) is opposed to the supply roller (63) of the first toner hopper (60), and the gap adjustment mechanism (90) and the like are set as described below.

That is, as shown in FIG. 9, the gap adjustment roller (90) creates a predetermined gap between the developing roller (32) and the supply roller (63) by pressure contact between the gap adjustment rollers (91) and (92)a. is retained.

In the opening/closing mechanism (80), as shown in FIG. 7, the opening/closing cover (82) of the first toner hopper (60)
2), and in the second toner hopper (70), the opening (72) is closed by the opening/closing cover (86). Therefore, color toner does not fall from the second toner hopper (70) in such a state.

In the locking mechanism (+00), as shown in Figure 1+, the first toner hopper (60) is locked in a non-removable state, and the second toner hopper (70) is set in a removable state.

In the drive mechanism (+20), as shown in FIG.
0), and the rotational force of the photosensitive drum drive gear (] 2 +) is applied to the developing roller drive gear (+22), the idler gear (123), and the supply roller drive gear (+24.). It is set to a transmittable state.

In the toner density adjustment means, the developing bias voltage (Vb),
A recovery bias voltage (V ss ) is set in each developing state.

When the print switch is turned on with each part of the developing device (5) set as described above, as shown in FIG. ), the developing roller (32), and the stirring blade (67) rotate, and the supply roller driving clutch (+
27), the supply roller (63) rotates.

As a result, in the toner storage tank (66), the stirring blade (6
Based on the rotation of step 7), the black toner is conveyed forward while being mixed and stirred, and at this time, toner blocking and crosslinking phenomena are prevented.

At the outer periphery of the supply roller (63) facing the toner storage tank (66), as shown in FIG. and the excess material is scraped off at the tip contact portion of the regulating blade (64).

The toner taken into the minute recess is removed by the regulation brake 1” (6
4) when passing through the pressure contact part with the regulating blade (64).
The supply roller is frictionally charged to a positive polarity by contact with the supply roller, and a thin layer of charged toner is formed on the surface of the supply roller.

On the surface of the developing roller (32), as shown in FIG.
When the carrier is conveyed in a magnetic brush state along the lines of magnetic force generated by the magnet of the magnetic roller (33), and the toner thin layer is conveyed to the opposing portion between the supply roller (63) and the developing roller (32). , on the surface of the developing roller (32) based on the scraping action of the flannel-shaped carrier and the difference between the bias voltages (Vb) and (Vs) applied to the developing roller (32) and the supply roller (63). Black toner is supplied.

Here, in the area where the developing roller (32) and the supply roller (63) face each other, not only the above-mentioned toner supply operation but also
In parallel, a collection operation is also performed to collect excess toner from the carrier on the developing roller (32) to the supply roller (63).

The toner supplied to the surface of the developing roller (32) is conveyed in the direction of the arrow based on the rotation of the developing roller (32).
First, the two are mixed on the circumferential surface of the developing roller. Next, the developer is transported to the stirring chamber (38), where it is further mixed well and charged to a predetermined value, and then moved to the regulating section (39).
The surface of the developing roller (32) that has passed through the opposing part is coated with toner and carrier at a predetermined ratio (toner concentration 26~10w).
The two-component developer mixed with t%) is adjusted and set to a developable state.

In this state, when the electrostatic latent image formed on the surface of the photoreceptor drum (3) is conveyed to the part facing the developing roller (32), the two-component developer is applied to this electrostatic latent image. It is rubbed and visualized as a black toner image.

The developer that has passed through the part facing the photoreceptor drum (3) is chopped at the part facing the regulating member (39) and most of it falls into the stirring chamber (38). The developer is mixed with the developer mixed in the direction of the arrow while forming a vortex, erasing the toner consumption pattern during development, and some of the developer is again held on the surface of the developing roller (32) and supplied. It is conveyed to the part facing the roller (63),
At this point, toner is supplied again. In addition, the stirring chamber (38)
The inner surface is a smooth curved surface, and the magnetic roller (33)
Since the developer is formed within the range of the magnetic binding force of the developing roller (
32) is constantly mixed and stirred.

The toner collected by the supply roller (63) is conveyed in the direction of the arrow based on its rotation, passes through the contact portion of the toner outflow prevention film (65), and is collected into the toner supply tank (66).

When the development operation of the electrostatic latent image on the original image is completed in this way, the developing bias voltage (Vb) and/or recovery bias ( Vs) is switched from the developing state to the standby state, some toner is collected from the surface of the developing roller (32) into the toner storage tank (66), and the toner concentration on the developing roller (32) is 0.1. ~2.
It is set to 0wt%.

D. Development section switching operation Next, from the black development state (PI) to the color development state (P2
), as shown in Fig. 4, hold the switching lever (42) and rotate the developing section (30) in the direction of the arrow (C''). (not shown) is displayed with a color mark (46).Furthermore, the vibration mechanism (47) and the like described below are operated as follows.

In the vibration mechanism (47) shown in FIG. 6, a vibrator (48),
The tips of (52) sequentially engage with the uneven portions (56) of the frame (57), and the striking portions (5) of each vibrator (48), (52)
0) and (54) are electrically and mechanically attached to the surfaces of the upper frame (35) and lower frame (36) by continuously hitting the upper frame (35) and lower frame (36), respectively. The black toner that is attached will be peeled off.

In the gap adjustment mechanism (90) shown in Figure 9.10, the gap adjustment roller (91) of the developing roller (32)
The supply roller (63) is separated from the gear adjustment port (92) of the toner hopper (60), and is biased by a spring (98) to move slightly in the biasing direction.

Further, when the developing section (30) is switched to the color developing state (P2), the gap adjustment roller (9) of the developing section (30)
1) is pressed against the gap adjustment roller (93) of the second toner hopper (70), and the gap adjustment roller (93) moves slightly in the direction opposite to the arrow direction against the biasing force of the spring (99). The developing roller (32) and supply roller (7)
3), a predetermined gap is uniformly formed along the axial direction.

In the opening/closing mechanism (80) shown in Fig. 7.8, the developing section (30
) When the segment gear (89) rotates in the direction of the arrow (C'), the toner hopper (6
The segment gears (83) and (87) of the first toner hopper (60) rotate in the directions of arrows (d) and (e'), respectively, and the opening (62) of the first toner hopper (60) opens with the opening/closing cover (
82), and the opening (72) of the second toner hopper (70) is opened when the opening/closing cover (86) is retracted therefrom. Therefore, in this state, black toner does not fall from the first toner hopper (60).

In the locking mechanism (100) shown in FIG. 11.12, as the developing frame (31) moves, the release part (101) slips into the opposite surface of the stopper (+03), and the other release part (102) (104), the first toner hopper (60) is set in a removable state, and the second toner hopper (70) is locked in a non-removable state.

In the drive mechanism (120) shown in FIG. 14.15, the developing roller drive gear (122) moves as the developing section (30) moves.
rotates around the photoreceptor drum drive gear (12) while meshing with the photoreceptor drum drive gear (12), and moves to the second toner hopper (70).
), and the rotational force of the photoreceptor drum drive gear (121) is transmitted to the developing roller drive gear (+25).
122) to the idler gear (125) of the second toner hopper (70) and the supply roller drive gear (126).
is set in a state where it can be transmitted.

E. Black toner removal operation As described above, the developing section (30) is in the concrete developing state (P1)
When the state is switched to the color development state (P2) and this is detected by the switch (S2), the main motor (2) is activated after a predetermined period of time has elapsed, and the drive mechanism (+20) shown in FIG. Body drum drive gear (121)
, the developing roller drive gear (122), and the supply roller drive gear (1-26) start rotating, and the surface of the photoreceptor drum (3) is uniformly charged based on the discharge of the charger (4). Ru.

Note that at this time, the supply roller drive clutch (not shown) attached to the support shaft (78) of the supply roller (73) of the second toner hopper (70) is turned off, and the supply roller drive gear (+26) is turned off. ) is rotated by the supply roller (73
) will not be transmitted.

Then, when switching the black toner remaining in the carrier held on the surface of the developing roller (32) and the developing section (30) from the concrete development state (Pl) to the color development state (P2), the vibration mechanism The black toner peeled off from the upper frame (35) and lower frame (36) based on the impact action of (50) is conveyed along the outer periphery of the developing roller (32) based on the rotation of the developing roller (32), and is transferred to the photosensitive drum (3). The developing roller (32) is electrostatically supplied to the surface of the developing roller (32).
Black toner is removed from the outer periphery. Note that by applying a developing bias voltage having the same polarity as the toner to the developing roller (32), the toner removal efficiency can be improved.

The black toner thus supplied to the surface of the photoreceptor drum (3) is conveyed in the direction of arrow (a) based on the rotation of the photoreceptor drum (3) and collected by the cleaning device (7).

When the black toner removing operation described above is carried out for a predetermined period of time and most of the black toner is removed from the circumferential surface of the developing roller (32), color development becomes possible.

As a result, black toner is not supplied to the electrostatic latent image during color development, and image quality does not deteriorate due to color mixing or the like.

The above-described toner removal operation is performed when the copying machine is powered on, after power outage or jam removal, and even after toner hopper replacement, and toner is removed from the developing section (30).

Note that the toner removal operation after turning on the power of the copying machine is performed during the warming-up time of the fixing device (27), the temperature control time,
It is carried out during the leveling time of the applied oil.

F Color development operation With the development device (5) set as described above,
When a print switch (not shown) is turned on, the developing bias (Vb
), the recovery bias voltage (Vs) is again set to the developing state.

Next, the photosensitive drum (3) rotates in the direction of the arrow (a) based on the drive of the main motor (2), and the developing roller (32) in the developing device (5) rotates in the direction of the arrow, and the supply roller is driven. A clutch (not shown) is turned on. As a result, in the second toner cartridge (70), a thin layer of color toner is formed on the outer peripheral surface of the supply roller (73).
Color toner is supplied to the surface of the developing roller (32),
At the outer periphery of the developing roller (32), a predetermined concentration (toner concentration of 20 to 10 wt%) consisting of carrier and color toner is applied.
A two-component developer is prepared.

The surface of the photoreceptor drum (3) is equipped with a charger (
After being charged by the discharge in step 4), an electrostatic latent image is formed based on the image exposure from the optical system (8), and this electrostatic latent image is supplied with color toner at a portion opposite the developing roller (32). The image is visualized as a color toner image.

When the above-mentioned development operation is completed, the development bias voltage (Vb) and recovery bias voltage (V s
) is switched to the standby state, and the toner concentration on the surface of the developing roller (32) is in the standby state (toner density: 0.1 to 2
．． 0wt%).

Further, when the developing section (30) is switched from the color development state (P2) to the concrete development state (PI), the concrete development state (P
In the same manner as the switching operation from I) to the color development state (P2), the upper frame (35) and lower frame (35)
The color toner adhering to 6) is peeled off and the developing section (
When the switch (Sl) detects that the developing roller (30) has been switched to the concrete developing state (PI), the developing roller (32)
starts driving, and the remaining color toner is supplied to the surface of the photoreceptor drum (3) and sent to the cleaning device (
7), and the state is set such that almost no color toner exists on the outer circumference of the developing roller (32).

Therefore, even if concrete development is performed next time, no color toner will appear on the image.

G. Detachable imaging unit (IU) The imaging unit (IU) is collected when the photoconductor drum (3) reaches a predetermined service life (for example, a predetermined number of copies) or by the cleaning device (7). When a predetermined amount or more of the toner is collected by the cleaning device (7), it is taken out from the front side of the copying machine main body (1).

Note that at this time, since the cleaning device (7) is taken out as an imaging unit (IU), there is little risk that the toner collected in the cleaning device (7) will spill and contaminate peripheral devices.

H Other Embodiments In the above embodiments, the present invention was applied to a developing device that uses a two-component developer consisting of toner and a carrier, but it can also be applied to a developing device that uses a component developer. be able to.

Further, in the embodiment, the developing section (30) is placed in the first state (
When switching between the first state (PI) and the second state (P2), the moving force is used to apply vibration to the developing section (30), but the present invention is not limited to this. While the frame is stopped, a vibration mechanism (not shown) moves the frame (
36) and (35) may be vibrated.

However, in this case, there is a drawback that a separate drive mechanism and its control mechanism are required to generate vibrations.

(Effects of the Invention) As is clear from the above description, in the developing device according to the present invention, as the developing section moves, vibration is applied to the frame covered by the developing roller, and the developer attached to the inner surface of the frame is removed from the developing roller. It is taken into the developer held on the surface.

Therefore, by consuming the collected developer or collecting it in the toner hopper when the developing device is not performing image formation, unnecessary developer can be removed from the developing section and a high-quality image without color mixture can be produced. can be obtained.

[Brief explanation of the drawing]

Figure 1 is a sectional view showing the general structure of the copying machine, and Figure 2 is a cross-sectional view showing the schematic configuration of the copying machine.
3 is a sectional view showing the structure of the developing section,
Fig. 4 is a perspective view of the switching mechanism, Fig. 5 is a sectional view showing the movement of the developing roller, Fig. 6 is a sectional view of the vibration mechanism, Fig. 7 is a sectional view of the toner hopper, and Fig. 8 is a side view of the opening/closing mechanism. Figure, No. 9
, FIG. 10 is a side view of the gap adjustment mechanism, FIG. 11 is a side view of the locking mechanism, FIG. 12 is a sectional view showing the locking mechanism in the locked state, and FIG. 13 is a sectional view showing the locking mechanism in the unlocked state. Figure 14 is an exploded perspective view of the drive mechanism;
The figure is a side view showing the switching state of the drive mechanism. ■...Copy machine body, 2...Main motor, 3...
Photosensitive drum (electrostatic latent image carrier), 5...Developing device, 7
... Cleaning device, 30... Developing section, 3.1 River developing frame, 32... Developing roller, 33... Magnetic roller, 35... Upper frame, 36... Lower frame, 41...・Switching mechanism, 42...Switching lever, 47・
- Vibration mechanism, 48... Vibrator, 60... First toner hopper, 61... Main body, 63... Supply roller, 70
... second toner hopper, 73 ... supply roller, 8
0... Opening/closing mechanism, 81... Frame, 82... Opening/closing cover, 83, 87.89... Segment gear, 9
0...Gap adjustment mechanism, 91°92.93...Gap adjustment roller, 100...Lock mechanism, 101...
・Lock release part, 103, 104...stopper, 107
, 108... Engagement hole, 109, 110... Engagement protrusion, 120... Drive mechanism, 121... Photosensitive drum drive gear, 122... Developing roller drive gear, 124.1
25... Supply roller drive gear, 127... Supply roller drive clutch. Patent applicant Minolta Camera Co., Ltd. Agent Patent attorney Maeda Ao and 2 others

Claims (1)

[Claims] (1) A plurality of developer supply means each having a developer supply roller and disposed on the side of the electrostatic latent image carrier; a developing section having a developing roller that selectively receives developer supply via a roller and supplies the developer to the surface of the electrostatic latent image carrier, at least a portion of which is covered with a frame; What is claimed is: 1. A developing device comprising a vibrating means for vibrating the frame as the developing section moves.