JPH07306595A - Toner supplying device - Google Patents

Abstract

PURPOSE:To facilitate the stirring of toner by the redrive of an agitator and simultaneously to prevent the damage of the agitator, when toner in a toner box is solidified. CONSTITUTION:This toner supplying device is constituted in such a manner that plural stirring members are radially arranged on a rotary shaft on the agitator in the toner box and a toner sensor is confronted with a residual toner detecting part formed on the bottom surface of the toner box from the outside, so that a wiping member attached to the rotary shaft passes through between the toner sensor and the residual toner detecting part. The residual toner is detected by the passage of the wiping member by the toner sensor (S7) and moreover, when the agitator is stopped (S8:No), it is stopped in a state where the stirring members enter the layer of the toner (S10), after the passage of the wiping member (S9:Yes).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner supply device for supplying toner to a developing device in an image forming apparatus such as a printer, a copying machine and a facsimile machine.

[0002]

2. Description of the Related Art As a recent dry developing system in which a developer is supplied to a developing area on the surface of a photosensitive drum to perform development, as disclosed in Japanese Patent Application Laid-Open No. 4-97179, it is adjacent to the photosensitive drum. The developing unit case is provided with a developing roller for supporting a mixture (developer) of toner and magnetic carrier on the outer peripheral surface thereof, and a toner supply slit is provided to the developing unit case through a partition wall. In the adjacent toner supply chamber, a stirring member is provided in a rotating agitator for supplying toner into the developing unit case. In addition, a transparent window is provided in a part of the toner supply chamber, and when the remaining amount of toner is detected by using a light transmission type sensor or a light reflection type sensor, the agitator is used to wipe the toner attached to the transparent window. It is proposed to provide a wiping member.

[0003]

However, if the image forming apparatus of this type is left unused for a long period of time, left in a high humidity or high temperature environment, or left in a vibrating environment, the toner is Toner may solidify in the supply chamber. On the other hand, in the conventional technique, the rotation stop position of the agitator is left arbitrarily left, so that the stirring member may stop on the upper side where there is no toner. In this case, even if the agitator, which was stopped on the upper side where the stirring member does not have toner, is driven again when the image forming apparatus is used, a situation occurs in which the stirring member cannot enter the solidified toner, and the toner is not stirred. There is a problem in that it is not possible to carry out the operation, and there are problems such as damage to the agitator and the stirring member.

The present invention has been made to solve this technical problem, and provides a toner supply device for a developing device in an image forming apparatus, which can surely perform a toner supply operation at the time of re-driving. The purpose is to

[0005]

In order to achieve the above object, a toner supply device according to claim 1 is configured such that a developing device for forming an image on a recording medium such as a sheet supplies toner to an agitator in a toner supply chamber. A supply device, wherein a plurality of stirring members for stirring the toner in the toner supply chamber are radially arranged around the rotation center of the agitator, and the control means supplies at least one stirring member when the rotation of the agitator is stopped. The control is performed so that the toner stays in the interior of the chamber.

According to a second aspect of the present invention, in the toner supply device according to the first aspect, a light-transmissive detection unit is provided at the bottom of the toner supply chamber, and an optical sensor is arranged in the detection unit. The control means controls the at least one stirring member to stop at the bottom side of the toner supply chamber based on the detection result of the passage of the wiping member in the agitator by the sensor.

[0007]

EXAMPLES Next, examples embodying the present invention will be described. FIG. 1 is a schematic side sectional view of a printer 1 as an image forming apparatus, and FIG. 2 is a partially cutaway sectional view of a case of a developing device 10. In the printer 1 of this embodiment, a paper feed cassette 3 as a paper feed unit is detachably mounted on one side of the main body case 2, and is stacked in the paper feed cassette 3 by a paper feed roller 4 and a separation pad 5. The formed recording paper P as a recording medium is separated one by one and is fed to a photoconductor unit 9 including a photoconductor drum 7 and a transfer roller 8 via a feed roller pair 6. A developing device 10, which will be described later, is arranged adjacent to the photoconductor unit 9 on the side close to the sheet feeding cassette 3, and on the opposite side, a fixing unit 13 including a heating roller 11 and a pressing roller 12 is arranged.

Below the photoconductor unit 9, a scanner unit 17 including a laser emitting section 14, a lens 15, a reflecting mirror 16 and the like, control boards 18 and 19, and a power supply unit 20.
Etc. are arranged, and the cover body 21 is provided with a keyboard 22 having a plurality of operation buttons. Charger 2
The surface of the photosensitive drum 7 pre-charged in 3 is irradiated with light emitted from the scanner unit 17 according to image data transmitted from an external device such as a computer (not shown), Form an electrostatic latent image on the surface,
Then, the developing sleeve 32 in the developing device 10 is rotated to perform development such that the magnetized powdery toner is supplied to visualize the latent image, and then the photosensitive drum 7 and the transfer roller 8 are connected to each other. The toner image is transferred to the paper P supplied during the period, and then the fixing unit 13 applies heat and pressure to the transferred image to fix the toner image on the paper P. From the discharge roller pair 24 to the printer 1
The paper is discharged to the paper discharge tray 25 of.

Next, the main part of one embodiment of the present invention will be described.
This will be described below with reference to FIGS. Developing device 1
As shown in FIG. 2, in the case 27 made of synthetic resin or the like in FIG. 0, the stirring chamber 30 and the developing chamber 34 are separated by a partition wall 35, and the partition wall 35 is provided on one side of the peripheral surface of the developing sleeve 32. The opening 36 is opened so as to face with.

A toner box 26 as a toner supply chamber for supplying a non-magnetic toner or a magnetic toner as a developer to the agitating chamber 30 has a pair of left and right bracket portions 27a protruding from one side of the case 27 (see FIG. 3) and is supplied detachably with the supplied toner 62.
(Refer to FIG. 7) is a second rotary blade in the stirring chamber 30.
It is stirred by the stirring member 31.

In the developing chamber 34, a magnet roller 38 is provided on the inner diameter portion.
Has a first stirring member 33 composed of a developing sleeve 32 containing therein and a rotating blade and the like below the developing sleeve 32, and is arranged so that one side of the rotatable developing sleeve 32 faces the outer peripheral surface of the photosensitive drum 7. There is. A regulating member 37 made of an elastic film such as a magnetically permeable PET (polyethylene terephthalate) film is attached near the opening 36, and the middle portion of the regulating member 37 is placed in the developing chamber 34. And extends downwardly to face the outer peripheral surface of the developing sleeve 32, and the free end of the regulating member 37 is the first.
The stirring member 33 is arranged so as to be close to the outside of the rotation trajectory of the stirring member 33.

As shown in FIG. 2, the second stirring member 31 as an agitator rotates in the direction of the arrow A to scrape up the toner in the stirring chamber 30 from the bottom toward the opening 36. First
The stirring member 33 rotates in the direction of the arrow B, and while stirring the toner 62 supplied from the opening 36 and the magnetic carrier previously stored in the developing chamber 34, the developing sleeve is temporarily passed through the bottom of the developing chamber 34. Bounce up toward the bottom surface of 32. The developing sleeve 32 rotates in the direction of arrow C, while the magnet roller 38 (where N poles and S poles are radially arranged alternately) in the inner diameter portion thereof rotates in the direction of arrow D, and the developing sleeve 32 moves in the direction of arrow E. Is close to the photoconductor drum 7 rotating in the direction.

At a portion of the developing chamber 34 near one side of the outer peripheral surface of the photosensitive drum 7, the outer peripheral surface of the developing sleeve 32 has a layer thickness of the toner carried by the magnetic carrier (developing layer thickness). ) Is provided for trimmer blade 39. The developing method used in this embodiment is a so-called two-component developing method in which the magnetic carrier is 95 to 98% (weight ratio) and the non-magnetic toner is 2 to 5% (weight ratio), and the magnetic carrier is 30 to 50%. Any of the so-called 1.5-component developing method in which the magnetic toner is 80% (weight ratio) and the magnetic toner is 20 to 70% (weight ratio) may be used.

Next, with reference to FIGS. 3 to 7, the construction of the mounting relationship between the toner box 26 as the toner supply chamber and the developing device 10 will be described. First, the developing device 1
As shown in FIG. 2, an arc-shaped partition wall 40 is provided on one side of the stirring chamber 30 of the case 27 (opposite to the partition wall 35), and the partition wall 40 is perpendicular to the plane of FIG. The second shutter 42 as a second shielding member for opening the substantially rectangular toner introduction port 41 extending in the direction and closing the toner introduction port 41 is a thin metal (aluminum or the like) plate having an arc cross section. It is formed so that the left and right ends thereof are mounted so as to rotate along guide grooves (not shown).

On the other hand, in the toner box 26, as shown in FIGS. 3 and 4, the lower half is arcuate, the upper half of the left and right sides in the longitudinal direction is rectangular, and the central portion 26a is cylindrical. , A pair of brackets 27a (only one of which is shown in FIG. 3) protruding from the case 27 of the developing device 10 are detachably mounted. When mounted on the case 27, the central portion 26a of the toner box 26 and the arcuate partition wall 40 of the case 27 are positioned concentrically with each other.

A toner outlet 43 is formed in the toner box 26 at a position facing the toner inlet 41 in the stirring chamber 30 at one side of the cylindrical central portion 26a. The first shutter 44 as a first shielding member that closes the above is formed on the first holding member 45 rotatably mounted along the outer periphery of the central portion 26a.

That is, the first holding member 45 and the second holding member 4
6 is formed in an arcuate shape in a side view so as to surround the outer periphery of the central portion 26a, and is connected by hinge portions 47 on both upper sides thereof, and the lower ends of the first holding member 45 and the second holding member 46. Removably engaged with engaging claws and engaging holes (both not shown) formed in the foot portions 45a and 46a. First
Operation holding portions 48 and 49 project from the holding member 45 and the second holding member 46, respectively, and the wide surface of the first holding member 45 serves as the first shutter 44, which is the first in the Y1 direction in FIG. When the holding member 45 is rotated, the upper opening 50 is opened so as to face the toner discharge port 43. On the contrary, when the holding member 45 is rotated in the Y2 direction, the first shutter 44 closes the toner discharge port 43. ing. When the first holding member 45 is rotated in the Y1 direction, engaging portions (not shown) are engaged with the engaging claws on the left and right sides of the second shutter 42, and the second shutter 42 is rotated downward. As a result, the toner introduction port 41 is opened.

Although not described in detail, the toner box 2
When 6 is removed from the developing device 10, the first shutter 44 on the toner box 26 side and the second shutter 42 on the stirring chamber 30 side are inadvertently rotated to rotate the toner discharge port 43.
Also, the toner inlet 41 is locked so as not to be opened, and the toner box 26 is attached to the pair of brackets 27.
The lock is released in the state of being mounted in the support groove 51 of a and 27a. Further, a sealing material made of a felt material or the like is stretched around the outer circumferences of the toner introducing port 41 and the toner discharging port 43 so that the toner does not leak out carelessly.

An agitator 52 as shown in FIGS. 5 to 7 is arranged in the toner box 26, and one end of the rotary shaft 53 of the agitator 52 is projected from one side of the toner box 26 as shown in FIG. The gear 54 is attached, and the power of the main motor 68 rotates the rotary shaft 53 in the direction of arrow F in FIG. 2 via a drive mechanism (not shown). Rotating shaft 53
Include first and second flexible left and right stirring members 55, 55 such as a polyester resin film, and a second flexible stirring member 56 such as a polyester resin film facing the toner discharge port 43. Are arranged so as to differ by 90 degrees with respect to the central angle of the rotating shaft 53.

On the other hand, a pair of translucent toner remaining amount detecting portions 57a and 57b, which are projected radially inwardly on the bottom surface of the central portion of the toner box 26 in the left-right longitudinal direction, are projected from the outside as shown in FIG. A toner sensor 58 such as a photo interrupter including a light portion 58a and a light receiving portion 58b is provided, and when passing between the pair of toner remaining amount detecting portions 57a and 57b, the opposite wall surfaces of the toner remaining amount detecting portions 57a and 57b are provided. And a wiping member 60 for cleaning the toner 62 to wipe the toner 62,
Similarly, the third stirring member 61 passing between the pair of remaining toner amount detecting portions 57a and 57b is attached to the rotation shaft 53 at a central angle θ (obtuse angle of 90 degrees or more, for example, 120 degrees) (FIG. 2). And FIG. 7). As an example of the wiping member 60, a cleaning brush 65 is planted on both left and right sides of the block 64 at the tip of the arm 63, and the cleaning brush 65 wipes the opposing wall surfaces of the remaining toner amount detecting portions 57a and 57b. However, it may be wiped with a flexible film (not shown).

The wiping member 60 is also used for detecting the remaining amount of toner. That is, the wiping member 60 is indicated by the arrow F.
The toner remaining amount detecting portions 57a and 57b by rotating in the direction
The toner 62 is scraped up when passing through the space. At that time, the light from the light projecting portion 58a can be received by the light receiving portion 58b. After that, the toner 62 falls between the pair of remaining toner amount detecting portions 57a and 57b and fills the gap, so that the light is blocked. By the way, when the amount of toner remaining in the toner box 26 is large, the light receiving portion 58b is used.
The time T from when the light is once received until it is not received again
Since the (ON time of the toner sensor 58) is short and the toner remaining amount decreases, the time T increases. If the toner 62 becomes extremely small, it will continue to receive light.

Utilizing this, the printer control unit 70
Thus, the remaining toner amount is detected from the information of the time T. As shown in FIG. 9, the control device 70 has a central processing unit (CPU) 71 that executes control of the entire printer.
A read-only memory (ROM) 72 storing a control program, a readable / writable memory (RAM) 73 storing various data at any time, control of the developing device 10 and rotation control of the agitator 52 in the toner box 26. And a gate array 74 for controlling the toner sensor 5
The detection signal of No. 8 is input, the main motor 68 is driven through the drive circuit 73, and the liquid crystal display panel 75 is controlled to operate.

Next, an image forming operation and a toner remaining amount detecting operation in the printer 1 thus constructed will be described with reference to FIG. First, when the power is turned on, the control shown in FIG. 10 is started, and the main motor 68 is driven to rotate the developing device 10, the photoconductor drum 7, the agitator 52, etc. (S1). Since the time required for one rotation of the agitator 52 in this embodiment is about 6 seconds, the time T during which the toner sensor 58 is in the ON state after 6 seconds has passed is a preset time To (for example, 3 seconds). It is determined whether it is short (S2). Then, the toner sensor 58
When the time T of the ON state of is 3 seconds or more (T ≧ To) (S2: No), it is determined that the toner remaining amount is low or absent, and “toner supply” is displayed on the liquid crystal display panel 75. (S3), the main motor 68 is stopped (S4).

On the other hand, when the time T of the ON state of the toner sensor 58 is shorter than 3 seconds (T <To), (S2: Ye
s), it is determined that toner is present and image formation is started (S).
5). At the start of image formation, when print data is input, printing for each page is executed (S6). Then, it is determined again whether the time T of the toner sensor 58 in the ON state is shorter than the preset time To (3 seconds) (S7). Here, O of the toner sensor 58
When N time is shorter than 3 seconds (T <To), (S
7: Yes), it is determined that toner is present, and it is determined whether print data for the next page exists (S8). If there is print data for the next page (S8: Yes), the process returns to S6 to continue printing.

On the other hand, when there is no print data for the next page (S8: No), the toner sensor 58 turns ON to determine whether or not the wiping member 60 has passed between the pair of toner remaining amount detecting portions 57a and 57b. The determination is made based on the timing of switching from the state to the OFF state (S9). Since the wiping member 60 is rotating in the direction of arrow F in FIG. 2 due to the drive of the main motor 68, when the wiping member 60 passes between the pair of toner remaining amount detecting portions 57a and 57b (S9: Yes), After a lapse of a fixed time (two seconds in this case), the main motor 68 is stopped (S10). As a result, the third stirring member 61 is stopped at the bottom of the toner box 26, that is, in the toner 62 layer.

Instead of the third agitating member 61, the first agitating member 45 or the second agitating member 46 may be stopped in a state of entering the toner layer. Further, when the ON time of the toner sensor 58 is 3 seconds or more (T ≧ To) during the printing operation (S7: No), it is determined that the toner remaining amount is low, and the liquid crystal display panel 75 displays “toner”. "Supply" is displayed (S3), and the main motor 68 is stopped (S4).

As described above, if the agitator 52 is stopped while at least one agitating member is in the toner layer serving as the toner retaining portion, when the agitator 52 is rotated again, the agitating member causes the toner 62 layer to form. Even if the toner 62 is tightened and solidified, the toner 62 is scraped up, so that the subsequent stirring operation of the toner 62 can be surely executed. In the above-described embodiment, after the wiping member 60 is detected by the toner sensor 58, the rotation shaft 53 is controlled to advance by the θ angle and then stopped, but the wiping member 60 also has a function as a stirring member. The agitator 52 may be stopped as soon as 60 is detected by the toner sensor 58.

Furthermore, in order to stop the agitator 52 in a state where at least one of the plurality of radially stirring members of the agitator 52 has entered the toner layer, it is associated with a sensor for detecting the rotational phase of the stirring member. It may be configured as. In the above embodiment, the toner box 2
6 was applied to the agitator 52, but the developing device 10
Agitator 3 in the stirring chamber 30 as the toner supply chamber of
It goes without saying that the same action and effect as described above can be obtained even when applied to No. 1.

When it is determined in S7 that the remaining amount of toner is low, the printing operation is stopped immediately after the liquid crystal is displayed in the above-mentioned embodiment, but normally even after the toner empty is detected. Since it is possible to print, a predetermined number of sheets may be printed.

[0030]

As described above, claim 1
In the toner supply device, the toner is supplied to a developing device for forming an image on a recording medium such as paper by an agitator in the toner supply chamber, and the toner in the toner supply chamber is agitated around the rotation center of the agitator. A plurality of agitating members for controlling the agitator are arranged radially, and the control means controls at least one agitating member so as to enter the toner accumulating portion in the toner supply chamber when the rotation of the agitator is stopped. Even if the toner is solidified in the toner retaining portion at the time of starting after the stop once, the stirring member located in the toner retaining portion can scrape the toner and start stirring, so that the subsequent toner stirring is surely performed. Therefore, there is an effect that an accident such as breakage of the agitator does not occur.

According to a second aspect of the present invention, there is provided a toner supply device according to the first aspect of the present invention, wherein a translucent detection section is provided at the bottom of the toner supply chamber, and an optical sensor is arranged in the detection section. According to the detection result of passage of the wiping member in the agitator, the control means controls the at least one stirring member to stop at the bottom side of the toner supply chamber. In addition to the effect, if the phase relationship between the wiping member and the stirring member is stored in the control means in advance, the control for stopping the stirring member in the toner accumulating portion in the toner supply chamber can be surely executed. That is the effect.

[Brief description of drawings]

FIG. 1 is a schematic side sectional view of a laser printer.

FIG. 2 is a partially cutaway side sectional view of a main part of a case of the developing device.

FIG. 3 is a perspective view seen from one side of the toner box.

FIG. 4 is a perspective view seen from the other side of the toner box.

FIG. 5 is a sectional view showing an agitator in a toner box.

FIG. 6 is a perspective view showing an agitator in a toner box.

FIG. 7: VII-VII of FIG. 5 showing the stopped state of the agitator
FIG.

FIG. 8 is an enlarged cross-sectional view of a main part of a toner remaining amount detection unit.

FIG. 9 is a functional block diagram of control means.

FIG. 10 is a flowchart of image formation and toner remaining amount detection control.

[Explanation of symbols]

 1 Printer 7 Photosensitive Drum 10 Developing Device 26 Toner Box 27 Case 30 Stirring Chamber 41 Toner Discharge Port 42 Second Shutter 43 Toner Inlet 44 First Shutter 52 Agitator 53 Rotating Shaft 55 First Stirring Member 56 Second Stirring Member 57a, 57b Toner Remaining Amount Detecting Section 58 Toner Sensor 60 Wiping Member 61 Third Stirring Member 62 Toner 68 Main Motor 70 Control Device

Claims (2)

[Claims] 1. A device for supplying toner to a developing device for forming an image on a recording medium such as paper by an agitator in the toner supply chamber, wherein the toner in the toner supply chamber is agitated around the rotation center of the agitator. A plurality of stirring members for arranging in a radial manner, and when the agitator stops rotating, at least one stirring member is provided with control means for controlling the agitator so as to enter the toner accumulating portion in the toner supply chamber. Toner supply device. 2. A light-transmitting detection unit is provided at the bottom of the toner supply chamber, and an optical sensor is arranged in the detection unit, and the detection result of passage of the wiping member in the agitator by the optical sensor is used. 2. The toner supply device according to claim 1, wherein the control means controls the at least one stirring member to stop at the bottom side of the toner supply chamber.