JPH01229275A - Toner supply device - Google Patents

Abstract

PURPOSE:To reduce the load placed on the driving system of a toner supply means by supplying toner from a cartridge which incorporates agitating blades to a toner hopper through a slanting path where a toner emptiness detecting means is provided, and conveying the toner to a toner supply roller by the rotation of the agitating blades. CONSTITUTION:The toner is supplied to the slanting path 17 with the agitating blades 6 incorporated in the toner cartridge 5. A heat generating body 18 is provided on the slanting path 17 to dry the toner and the emptiness detecting device 40 is provided to detect the amount of toner. The toner hopper is formed on the bottom part of the slanting path 17, and the toner is conveyed with the agitating blades 16 and supplied to the toner supply roller 20 through a control blade 21. This constitution loads the bottom surface of the slanting path 17 with part of the weight of the toner supplied from a toner supplementing part 2 to a toner supply part 11, so the toner is prevented from being compressed to flocculate, thereby reducing the load on the driving system of the toner supply means.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a toner supply device for supplying toner to a developing section in an image forming apparatus equipped with an electrophotographic copying process.

(Prior Art) Generally, an image forming apparatus such as a copying machine is provided with a toner supply device that replenishes toner consumed in a developing section during development. There has been proposed a toner replenishing section which includes a toner hopper provided at the bottom thereof, and a toner replenishing section that is equipped with a toner conveying means such as a screw, and that drops and replenishes the charged toner into the toner hopper.

(Problems to be Solved by the Invention) However, in the toner supply device, since toner is deposited on the toner supply means, the load placed on the drive system of the toner supply means becomes large.

Further, the toner at the bottom is compressed and agglomerated by its own weight, and if the toner hopper is equipped with a stirring means, for example, there is a problem in that the stirring resistance is large and a large load is placed on the drive system.

(Means for Solving the Problems) Therefore, the present invention has been made to solve the above problems, and will be described with reference to FIG. supply roller) (20)
a toner supply unit (toner hopper) (15) having
ii) a slope (17) formed by extending the toner supply section (15) diagonally upward; and (iii) a toner conveying means [toner stirring blade] (6
), and the toner supply section (1
5), a toner replenishing section (2) for replenishing toner, and (i
v) Toner empty detection means (empty detection device) (4, 0) provided in the above-mentioned (17).

(Function) In the toner supply device having the above configuration, the toner supply section (
The toner in 2) is roughly transported (17) by the toner conveying means (6).
sent to.

On the other hand, the toner in the toner supply section (15) is sent to the development section (12) by a toner supply means (20) and subjected to development.

When the toner in the toner supply section (20) is gradually consumed with the consumption of toner in the developing section (12), the toner supply section (20) is gradually replenished with an amount of toner corresponding to the consumed amount through the rough (17). Ru.

Here, since a percentage of the weight of the toner (17) is borne by the bottom surface of the toner (17), the toner supply means (
The toner pressure acting on 20) is small.

Further, when the rough toner (17) gradually decreases, this state is detected by the empty detection device (40), and it is recognized that the toner replenishing section (2) needs to be replenished with toner.

(Example) The present invention will be described below with reference to the accompanying drawings.

I. Configuration of developing device [1] Schematic configuration FIG. 1 shows a developing device (A) according to the present invention, which includes a toner replenisher (2) at the rear of the main body (1).
, a developing device (10) is provided at the front portion on the side of the photoreceptor drum (100).

[:ii:l Toner replenisher (2) The toner replenisher (2) is formed with a cylindrical cartridge accommodating portion (3), which has a replenishment opening for replenishing toner to the developing device (10). (4) is formed. Also,
A toner cartridge (5) containing toner (To) is removably attached to the cartridge accommodating portion (3), and an opening (7) formed on the outer periphery of the toner cartridge (5) It is aligned with the replenishment opening (4). Further, the toner cartridge (5) has a built-in stirring blade (6), and this stirring blade (6) is driven by a drive (not shown) when the toner cartridge (5) is housed in the housing part (3). It is drivingly connected to the system and can be rotated in the direction of arrow (a).

[iii:] Developing device (10) The developing device (10) is roughly composed of a toner supply section (11), a developing section (12), and a developer stirring section (13).

(a) Toner supply section (11) The toner supply section (11) receives the toner supplied to the developing device (10) from the toner cartridge (5) of the toner supply device (2), and transfers it to the developing section ( 12), which connects the bottom casing of the main body (1) and the developer stirring section (1).
A toner hopper (15) communicating with the replenishment opening (4) of the toner replenisher (2) is formed between the toner replenisher (5) and the casing (14) forming the bottom of the toner replenisher (2).

At the bottom of this toner hopper (15) is a stirring blade (16).
is arranged so as to be rotatably driven in the direction of the arrow (b), and has a bottom portion where the stirring blade (16) is housed and a replenishment opening (4).
), and as shown in FIG. 2, the bottom surface inclination angle (θ) is set at an angle at which toner easily flows.

In addition, a heating element (18) is provided on the bottom of the roughness (17), and this heating element (18) is connected to a power source (not shown), and the temperature of the generated heat is maintained at an appropriate level without adversely affecting the toner on the side. The device is set to heat the toner to keep it dry.

Furthermore, an empty detection device (
40), the details of which are shown in FIG.

In this empty detection device (40), an empty detection plate (41) is arranged roughly along the line (17), and the upper end of the empty detection plate (41) is attached to a support shaft (42) rotatably provided on the main body casing. ), and the protruding portion of the support shaft (42) from the main body casing is attached to the operating portion (43). That is, the empty detection plate (41) and the operating part (4
3) are integrated via a support shaft (42). Also,
The operating portion (43) has one end locked to the main body (1) and the other end of a spring (44) locked to the empty detection plate (41).
) is urged in the direction of arrow (c) around the support shaft (42), but with the toner (17) almost full of toner, it is pressed against the bottom surface of the rough (17) by the weight of the toner. ing. Furthermore, the lower end of the empty detection plate (41) and the bottom surface of the rough (17) are connected by B46),
Toner is only prevented from going around to the back surface of the empty detection plate (41).

On the other hand, a switch (45) is disposed on the side of the main body (1), and as described above, the operating part (43) is pressed against the empty detection plate (41) or roughly (17) by the weight of the toner. Touch the contact part of the switch (45) to turn it off, and when the amount of toner (17) is less than the predetermined amount, the empty detection plate (41) is activated by the spring (44).
), the operating section (43) operates in the direction of the arrow (C), shifts to a non-contact state with the operating section (43) or the contact section of the switch (45), turns it on, and releases toner based on the on signal. This is to notify that the toner cartridge is empty, that is, that the toner cartridge (5) should be replaced.

Returning to FIG. 1, at the front of the toner hopper (15), a toner supply roller (20) having a minute recess formed on its outer peripheral surface is arranged so as to be rotatable in the direction of arrow (d). is a regulating blade (
A toner return prevention member (22) is interposed between the lower outer peripheral surface of the toner supply roller (20) and the main body (1).

The toner supply roller (20) is connected to an AC power source (23).
) and DC voltage 1 (24) are connected in series, and AC voltage (Vr
A recovery bias voltage (V rms + V ss), which is obtained by superimposing a DC voltage (Vss) on the voltage (V rms ), is applied.

(b) Developing section (12) The developing section (12) includes a lower developing sleeve (25) and a lower developing sleeve (28) facing the photoreceptor drum (1,00).
are arranged adjacently below ``1'', and arrows (e) and (f
) direction, and the photoreceptor drum (10
The developing sleeve (25) located on the downstream side with respect to the rotation direction [arrow (h) direction] of the toner supply roller (20
).

In addition, the tip of the casing (14) is opposed to the rear side of the area where the developing sleeves (25) and (28) are opposed, and the casing (14) and the developing sleeve (25),
A predetermined cap is formed between (28) and
The tip of a height regulating member (30) provided on the main body (1) is opposed to the upper outer circumferential surface of the lower developing sleeve (28) at a predetermined distance.

Further, the developing sleeves (25) and (28) are supplied with a developing bias (Vb) from the DC power supplies (27) and (31), respectively.
I), (V b 2) are applied.

The developing sleeves (25) and (28) each have a magnet body (2
6) and (29) are built in a fixed state, and in the magnet body (26) built in the lower developing sleeve (25), the magnetic poles (N, ~N3.S, ~S3) are alternately S and N. In particular, the magnetic pole (Sl) is arranged in the part facing the photoreceptor drum (100), the magnetic pole (N2) is arranged in the part facing the toner supply roller (20), and the magnetic pole (N2) is arranged in the part facing the lower developing sleeve (28). Magnetic poles (S3) and (N3) are arranged in order along the rotational direction.

On the other hand, the magnet body (29) has magnetic poles (N4.~.N6, N4.
~.

S7) are arranged as shown in the figure, and in particular, a magnetic pole (N4) is arranged at the part facing the photoreceptor drum (100), and a magnetic pole (N6) having the same polarity is arranged at the opposite rear side.
), (S7) are arranged adjacent to each other, and a non-magnetic pole part (
Z) is formed. In addition, the lower developing sleeve (25)
Magnetic poles (N5) and (N5) are arranged in the opposite part of the magnetic body (26), respectively.
), and in the relationship between these upper and lower opposed magnetic poles (N3) and (N5), it is a magnetic pole (N5) or a strong magnetic pole, and in the relationship between magnetic poles (N3) and (N5), it is a magnetic pole. (N3) has a stronger magnetic pole.

(c) Developer stirring section (13) The developer stirring section (13) is formed on the toner supply section (11), and the stirring tank (32) has a packet roller (33) facing the developing sleeve (28). ) are arranged so as to be rotatably driven in the direction of arrow (g), and a two-component developer consisting of toner and carrier is housed in the outer periphery of the stirring tank (32) and the developing sleeves (25) and (28). Retained.

■ In the developing device (A), which has a configuration that is more than the operation of the image device, the toner in the toner cartridge (5) is mixed and stirred based on the rotation of the stirring blade (6), and the toner is mixed and stirred in an amount commensurate with the amount consumed by development. The amount of toner flows through the openings (4) and (7) roughly (
17).

Therefore, as long as there is toner in the toner hopper (15), the toner (17) will be filled with toner, and in this state, the empty detection plate (41) will be filled with toner (17) due to the weight of the toner.
7), and the switch (45) is in the off state.

Some percentage of the weight of the toner located in the rough bottom surface (17) is borne by the rough bottom surface, so the toner supply roller (20
), the toner in the toner hopper (15) is not abnormally compressed and agglomerated, and the load on the drive system of the stirring blade (16) is reduced. Incidentally, the toner weight borne by the rough bottom surface changes depending on the inclination angle (θ) of the rough bottom surface.

In addition, a predetermined voltage is applied to the heating element (18) located approximately at (17) to maintain the toner located at approximately (17) in a dry state. Therefore, even if condensation or the like occurs in the toner hopper (15) or toner tray (5) due to temperature changes and the toner becomes moist, the toner is heated roughly (17) and the moisture is removed from the toner. No problems such as solidification will occur.

The toner sent to the toner hopper (15) is
16), and the toner located near the outer periphery of the toner supply roller (20) is transported in the direction of arrow (d) based on the rotation. Then, the toner supply roller (2
The toner scraped off from the outer periphery of the toner (15) remains in the toner hopper (15). On the other hand, the toner that has passed through the tip contact portion of the regulation blade (21) is conveyed to the toner supply area (X) where the developing sleeve (25) and the toner supply roller (20) face each other, and here the toner is transported to the toner supply area (X) where the developing sleeve (25) The scraping action of the carrier and developer conveyed in a magnetic brush state according to the rotation of the developing bias voltage (v b
, ) and the recovery bias voltage (Vrms+Vss) by electrostatic attraction force based on the potential difference between the developing sleeve (25) and the recovery bias voltage (Vrms+Vss).

In addition, in the toner supply area (X), a toner collection operation is performed by the electrostatic attraction force in parallel with the toner supply operation,
When the toner concentration of the developer held on the developing sleeve (25) [the content ratio of toner to carrier] is equal to or higher than a predetermined value, the toner is collected from the developing sleeve (25) to the toner supply roller (20). Ru.

The toner supplied to the surface of the developing sleeve (25) is taken into the developer held on the outer periphery of the developing sleeve (25), and is mixed with the developer while being mixed with the developer.
) is conveyed in the direction of arrow (e) based on the rotation of the developing sleeve (28), and is attracted by the magnetic poles (N3) to (N5) at the portion facing the developing sleeve (28), and transferred onto the developing sleeve (29).

In addition, as explained earlier, the magnetic pole (N5) is a stronger magnetic pole than (N3), and moreover, the developing sleeve (25)
and (28), a repulsive magnetic field is formed between magnetic poles (N3) and (N5), and magnetic poles (N3) and (N5), respectively, and the developer is prevented from flowing there. At the same time, the developer in the lower developing sleeve (25) is easily transferred to the lower developing sleeve (28).

The developer transferred from the lower developing sleeve (25) to the lower developing sleeve (28) is conveyed in the direction of arrow (f) based on the rotation of the developing sleeve (28), and is transported between the magnetic poles (N6) and (S7).
) is separated from the outer periphery of the developing sleeve (28) and collected in the stirring tank (32), and the developer flows based on the rotation of the bucket roller (33). The toner and carrier are thoroughly mixed and stirred.

While the developer in the stirring tank (32) is being mixed and stirred, some of the developer is returned to the developing sleeve (
It is held on the surface of the developing sleeve (28) and is conveyed in the direction of arrow (f) based on the rotation of the developing sleeve (28).
30), the amount of conveyance is regulated at the opposing portion.

The developer that has passed through the portion facing the height regulating member (30) is conveyed in the direction of the arrow (f) in a magnetic brush state, and is delivered to the developing area (Y2) where the photosensitive drum (100) and the developing sleeve (28) face each other. , the electrostatic latent image formed on the outer peripheral surface of the photoreceptor drum (1,00) is rubbed and visualized as a toner image.

The developer that has passed through the development area (Y,) is transferred to the development sleeve (
Based on the rotation of the developing sleeve (28), the developing sleeve (25) is further conveyed in the direction of the arrow (f), and is attracted by the magnetic pole (N3) of the magnet body (26) at the part facing the developing sleeve (25).
).

In addition, the developing sleeves (25) to (28) explained earlier
Similar to the transfer operation of the developer to the magnetic pole (N3), the magnetic pole (N3)
It is a stronger magnetic pole than the magnetic pole (N5), and the magnetic pole (N3) and (N
5) and because a repulsive magnetic field is formed by the magnetic poles (N3) and (N5), the developer transfer operation here is performed smoothly.

The developer held on the surface of the developing sleeve (25) is conveyed in the direction of arrow (e) based on its rotation, and comes into contact with the static ms image on the photoreceptor drum (100) again in the developing area (Y,). , toner is again supplied to the toner image visualized in the development area (Y2).

Therefore, toner is replenished even in the developing area (Y2) where toner supply was insufficient, and density unevenness and white spots due to insufficient toner supply do not occur.

The developer that has passed through the development area (Yl) is connected to the magnetic pole (N I)
.

(S,) and is conveyed to a portion opposite to the toner supply roller (20), where an amount of toner corresponding to the amount consumed by development is supplied.

The toner supplied here is conveyed along the outer peripheral surfaces of the developing sleeves (25) and (28) as described above.

That is, as shown in FIG.
5), (28) are circulated and transported along the flow ■ to They are mixed and stirred, and further, the electrostatic latent image on the photosensitive drum (100) is rubbed twice in the development areas (Y2) and (Y,).

Further, the toner supplied from the toner supply section (11) to the developing section (12) is delivered to the developing sleeve (25).

(28) while being mixed and agitated while being transported around the outer circumference of the developing sleeve (28), and is peeled off from the outer circumference of the developing sleeve (28) and thoroughly mixed in the stirring chamber (32).
, ), (Y, ), and will not be subjected to development due to poor charging.

Therefore, even if the photoreceptor drum (100) is rotated at high speed, the frequency of contact between the electrostatic latent image formed thereon and the toner increases, supplying the required amount of well-charged toner, and improving image tracking. improves.

As the development is repeated as described above, the toner in the toner cartridge (5) is gradually consumed, and as a result, the amount of toner in the rough tube (17) reaching the bottom of the toner hopper (15) decreases. Then, in the empty detection device (40), the toner empty detection plate (4
1) rotates in the direction of the arrow (C-16= ), and when the rotation angle exceeds a predetermined angle,
The operating portion (43) is brought into a non-contact state with the switch (45), and toner empty, which is a state in which toner should be replenished, is notified.

Then, by installing a new toner cartridge (5), toner is roughly replenished (17) from the cartridge (5), and the toner empty state is resolved.

■, Other Examples In the above description, there is an empty detection plate (41) on the rough bottom surface.
is used to detect the amount of toner in Rough (17) and manage the empty state. However, the means for detecting the empty state is not limited to the above embodiment (it may be performed using a pressure sensor, etc.). You can.

(Effects of the Invention) As is clear from the above description, in the developing device according to the present invention, some of the weight of the toner supplied from the toner supply section to the toner supply section is borne by the rough bottom surface. The bulk density of toner filling the roller becomes smaller. In other words, toner compression aggregation is prevented.

Therefore, the supplied toner is efficiently dispersed and incorporated into the developer of the developing sleeve.

As a result, there is no background fogging or toner scattering due to insufficient charging of the toner, and even if the toner supply section is equipped with a stirring means, the toner stirring resistance is reduced, toner agitation performance is improved, and the toner supply is improved. The load on drive systems such as rollers is also reduced.

[Brief Description of the Drawings] Fig. 1 is a cross-sectional view of the developing device according to the present invention, Fig. 2 is a cross-sectional view of the main part of the developing device, and Fig. 3 is a cross-sectional view showing the developer conveyance situation at the outer periphery of the developing sleeve. It is a diagram. A... Developing device, 1... Main body, 2... Toner replenisher, 5... Toner cartridge 10... Developing device, 11 Toner supply section, 12... Developing section, 13... Developer stirring Part, 15... Toner supply part, 18... Heating element, 17... Rough, 20
- Toner (M roller, 21... regulation blade, 25.
28 ・Developing sleeve, 26, 29 Magnet body,
30. Head height regulating member, 32. Stirring chamber, 33.. Stirring roller, 40.. Empty detection device, 41.. Empty detection plate, 43. Operating section, 45.. Switch, 100. Photosensitive drum, X... Toner supply area, Y. , Y, . . . development area, Z: non-magnetic pole area. Patent applicant Minolta Camera Co., Ltd. Agent Patent attorney Haka Aoyama 1 person Figure 2 Figure 3

Claims (1)

[Claims] (1) A toner that includes a toner supply section having a toner supply means, a slope formed by extending the toner supply section diagonally upward, and a toner transport means, and supplies toner to the toner supply section via the slope. A toner supply device comprising: a replenishment section; and a toner empty detection means provided in the slope.