JPH03271784A - Image forming device - Google Patents

Abstract

PURPOSE:To prevent deterioration of toner by disposing a multiple number of toner sensors along a logitudinal direction of a developer carrier and controlling the drive of a toner agitating means, a toner carrying means, and a toner replenishing means based on this detected result. CONSTITUTION:A toner sensor 5a is disposed in the vicinity of entrance side of agitating/carrying means 6, a toner sensor 5a is installed on the opposite side, and the toner quantity inside a developing container 3 is detected by toner sensors 5a and 5b, in the container 3 of the developing device. Then the detected signal of the sensor 5 is imparted to a control means, and the drive and stopping of the agitating / carrying means 6 and the replenishing means 4 are controlled by the control means. Thus, leveling of the specified toner T can be obtained, it is not necessary to make the ability of the toner agitating/carrying means 6 greater, and the toner T can be prevented from being deteriorated.

Description

DETAILED DESCRIPTION OF THE INVENTION 1. The present invention relates to an electrophotographic or electrostatic recording image forming apparatus, and in particular to an image forming apparatus that converts a latent image formed on an image carrier into a visible image. The present invention relates to an image forming apparatus having a developing device.

[Second Plate I] As a developing device for converting a latent image formed on an image carrier into a visible image, one having a structure as shown in FIG. 7 is conventionally known.

A developing device having such a structure includes a developer carrier 2 that supports a developer (hereinafter referred to as "toner") in a developer container 3 and conveys it toward an image carrier l such as a photosensitive drum. .

Further, facing the developer carrier 2, a toner stirring means and a toner conveying means are, in this example, a screw conveyor or the like extending parallel to the developer carrier 2 in its width direction.
A stirring/conveying means 6 having both the functions of stirring means and conveying means is arranged, and the toner in the hopper 7 is replenished from the hopper 7 to the inlet 11 of the stirring/conveying means 6 by the replenishing means 4.

Further, a toner sensor 5 is disposed in the container 3 of the developing device, close to the inlet side of the stirring/conveying means 6. When the toner sensor 5 sends a toner out signal for a predetermined period of time, a control means (not shown) operates based on this signal, drives the replenishment means 4, supplies toner from the hopper 7 into the container 3, and When the toner presence signal is transmitted for a predetermined period of time, the replenishing means 4 is stopped.

However, with this kind of developing device, if the toner level inside the developing device is not kept horizontal due to the installation situation, the toner level in the developing device will be tilted, and the hopper will be adjusted according to the signal from the toner sensor. The toner may have been supplied from
On the side where the toner sensor is not located, that is, on the side where the developing device is low, there is an oversupply and the toner aggregates, producing an abnormal image.On the other hand, on the side where the toner sensor is located high, the supply cannot keep up and the image is distorted. White spots etc. may occur. In addition, even if the horizontal state is maintained, if the stirring/conveying means 6 that levels the toner in the developing device is operated excessively, it will affect the deterioration of the toner, so it is difficult to increase its capacity. However, there are limitations and it is not possible to perform sufficient leveling, and it is not possible to completely prevent the occurrence of white spots in the image.

Therefore, an object of the present invention is to provide a plurality of toner amount detection sensors along the longitudinal direction of a developer carrier, and to control the driving of toner stirring means and conveyance means based on the signals of the sensors, thereby achieving a predetermined amount of toner. Toner leveling can be achieved, eliminating the need to increase the capacity of toner agitation and transport means, thereby preventing toner deterioration, and even if the developing device is installed at an angle, the developer carrier It is an object of the present invention to provide an image forming apparatus that can stably supply toner to a user and always obtain high-quality images.

for The above object is achieved by an image forming apparatus according to the present invention.

In summary, the present invention provides an image that converts a latent image formed on an image carrier into a visible image using a developing device equipped with a developer carrier that carries developer and transports the developer toward the image carrier. In the forming apparatus, the developing device includes a conveying means for conveying the developer to the developer carrying member, an agitating means for stirring the developer within the developing device, and a plurality of parts arranged along the longitudinal direction of the developer carrying body. and a detection means for detecting the amount of developer disposed individually, and the developer conveying means and stirring means are drive-controlled by a signal from the developer amount detection means. This is an image forming apparatus.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The image forming apparatus according to the present invention will be described in more detail below with reference to the drawings.

Referring to FIGS. 1 and 2, the image forming apparatus according to the present invention can be embodied in any electrophotographic or electrostatic recording type image forming apparatus, and FIGS. Referring to the figure, an image carrier 1 such as an electrophotographic photosensitive drum, for example.
A developing device that converts a latent image formed into a visible image is mainly illustrated. Various processes for forming latent images exist and are well known to those skilled in the art and will not be discussed in further detail.

In this embodiment, the developing device has the same configuration as the conventional developing device shown and explained in FIGS.
A developer carrier 2 for carrying the developer therein, that is, toner T, and transporting it toward an image carrier 1 such as a photosensitive drum.
has. The developer carrier is generally a cylindrical developing sleeve, and includes a magnet (not shown) inside.

Furthermore, a toner stirring means and a toner conveying means are arranged opposite the developing sleeve 2. In this embodiment, the toner stirring means and the conveying means are a screw conveyor 6 extending in parallel with the developing sleeve 2 in its width direction, and is configured to have both the functions of the stirring means and the conveying means. Hopper 7
The toner T inside is replenished from the hopper 7 to the inlet 11 of the stirring/conveying means 6 by the replenishing means 4.

Further, according to the present invention, in the container 3 of the developing device, stirring and
A toner sensor 5a is disposed close to the entrance side of the conveying means 6, and a toner sensor 5b is disposed on the opposite side along the longitudinal direction of the developing sleeve 6. Toner sensors 5a and 5b detect the amount of toner in the developer container. Although two toner sensors are provided in this embodiment, the present invention is not limited to this, and a plurality of toner sensors can be arranged as desired.

The detection signal of the sensor 5 is given to a control means (not shown), and the control means controls driving and stopping of the stirring/conveying means 6 and the replenishing means 4.

When the replenishing means 4 is driven, the toner in the hopper 7 is transferred through the inlet 11 to the point at which the stirring/conveying means 6 starts feeding! When the stirring/conveying means 6 is driven, the container 3
The toner supplied from the hopper 7 is distributed along the width direction, that is, the longitudinal direction, of the developing sleeve 2, and the toner is pushed toward the developing sleeve 2 while being stirred.

According to the present invention, the stirring and conveying means 6 and the replenishing means 4 are controlled by signals from the toner sensors 5a and 5b.Next, the control mode of the stirring and conveying means 6 and the replenishing means 4 will be explained. .

Table 1 shows one control mode of the stirring/conveying means 6 and the replenishing means 4.

Table 1 (1) When the “toner present” signal is output from the toner sensor 5a,
If the toner sensor 5b also outputs a "toner present" signal, if such a signal is transmitted for a predetermined period of time, the agitation/conveying means 6 is turned on after a predetermined period of time.
The drive of the replenishing means 4 is turned off, and toner is not supplied.

(2) When the “no toner” signal is detected by the toner sensor 5a,
When the toner sensor 5b outputs a "toner present" signal, if such a signal is transmitted for a predetermined period of time, the agitation/conveyance means 6 is turned on and the replenishment means 4 is turned on. The drive is turned on and toner is supplied.

(3) When the “toner present” signal is detected by the toner sensor 5a,
When the toner sensor 5b outputs a "no toner" signal, if such a signal is transmitted for a predetermined period of time, the stirring/conveying means is turned on and the replenishing means is turned on. Turn off and do not supply toner.

(4) When the “no toner” signal is detected by the toner sensor 5a,
When the toner sensor 5b outputs a "no toner" signal, if such a signal is transmitted for a predetermined period of time, the stirring/conveying means is turned on and the replenishing means is turned on. Turn on and supply toner.

Another embodiment of the invention is shown in FIGS. 3 and 4.

In this embodiment, unlike the previous embodiment, the toner stirring means 6
a and the toner conveying means 6b are constructed separately. In this embodiment, the stirring means 6a is a crank-shaped stirring rod, and is located between the developing sleeve 2 and the transporting means 6b. The conveying means 6b is generally a screw conveyor. Further, the toner sensors 5a and 5b are provided on the inside wall of the container 3, close to the stirring means 6a.

Table 2 shows the control mode of the toner stirring means 6a and the toner conveying means 6b in this embodiment.

Table 2 (1) When the toner sensors 5a and 5b transmit a "toner present" signal for a predetermined period of time, both the drive of the conveyance means 6b and the drive of the replenishment means 4 are turned off, and toner supply and conveyance are stopped. Stop both.

(2) When the toner sensor 5a outputs a "no toner" signal and the toner sensor 5b outputs a "toner present" signal, after a predetermined period of time, the conveying means 6b moves the toner in one direction. In this embodiment, the paper is driven to be transported in the direction indicated by the arrow in FIG. 4, and the drive of the replenishing means 4 is turned off.

(3) When the “toner present” signal is detected by the toner sensor 5a,
When the toner sensor 5b outputs a "no toner" signal, after a predetermined period of time, the conveying means 6b conveys the toner in another direction, in this embodiment, in the direction indicated by the arrow in FIG. The replenishing means 4 is turned off.

(4) When the toner sensor 5a outputs a "no toner" signal and the toner sensor 5b outputs a "no toner" signal, after a predetermined period of time, the conveying means 6b transports the toner as shown in FIG. The toner is driven to be conveyed in one direction of the arrow, and the replenishing means 4 is turned on to supply toner.

Another embodiment of the invention is shown in FIGS. 5 and 6.

In this embodiment, the toner stirring means 6a and the toner conveying means 6
In addition to the toner sensor b being configured separately, the toner sensor is
Main sensor 5 (5a, 5b) and pre-sensor 5° (
It is composed of a pair of sensors 5a' and 5b'. In this embodiment, the stirring means 6a is a crank-shaped stirring rod, and is located between the developing sleeve 2 and the conveying means 6b.

The conveying means 6b is generally a screw conveyor.

Further, the main sensors 5a and 5b are arranged closer to the conveying means 6b than the stirring means 6a, and the pre-sensors 5a' 5
b' is arranged one-sidedly toward the developing sleeve 2 side. In this embodiment, the main sensor 5 (5a, 5b) and the pre-sensor 5
° (5a', 5b') are arranged differently in the developing device, but they can also be arranged at the same position and have different sensing levels. Furthermore, it is also possible to use one sensor as a sensor having a plurality of sensing levels. In any case,
By configuring the toner sensor as in this embodiment, stable supply of toner becomes possible.

Table 3 shows how the toner stirring means 6a and toner conveying means 6b are controlled in this embodiment.

Table 3 To further explain with reference to Table 3, (1) Toner sensors 5a', 5b', 5a, 5b
When the "toner present" signal is transmitted for a predetermined period of time, both the driving of the conveying means 6b and the driving of the replenishing means 4 are turned off, and both toner supply and conveyance are stopped.

(2) When the toner sensors 5a and 5b output a "toner present" signal, the toner sensor 5a outputs a "toner absent" signal, and the toner sensor 5b outputs a "toner present" signal, and the toner sensor 5a' outputs a "toner absent" signal. , 5b', when a "toner present" signal is transmitted for a predetermined period of time, the conveyance means 6b
is driven to convey the toner in one direction, in this embodiment, in the direction indicated by the arrow in FIG. 4, and the replenishing means 4 is turned off.

(3) When the toner sensors 5a and 5b output a "toner present" signal or the toner sensor 5a outputs a "toner present" signal and the toner sensor 5b outputs a "toner absent" signal, and the toner sensor 5a' outputs a signal indicating "toner present", 5b', when the "no toner" signal is transmitted for a predetermined period of time, the conveying means 6b
is driven to convey the toner in another direction, in this embodiment, in one direction indicated by the arrow in FIG. 4, and the drive of the replenishing means 4 is turned off.

(4) When the toner sensors 5a, 5a, 5b' send out a "no toner" signal and the toner sensor 5b sends a "toner present" signal for a predetermined period of time, the conveying means 6b moves the toner to the arrow φ shown in FIG. The replenishing means 4 is turned on.

(5) When the toner sensor 5a sends a signal indicating ``toner present'' and the toner sensors 5a, 5b', and 5b send a signal indicating ``no toner'' for a predetermined period of time, the conveying means 6b transports the toner in the direction indicated by the arrow in FIG. is driven to convey in the direction,
The drive of the replenishing means 4 is turned on.

(6) If the toner sensor 5a, 5a', 5b, 5b' sends a "no toner" signal for a predetermined period of time,
The conveying means 6b is driven to convey the toner in one direction indicated by the arrow in FIG. 4, and the replenishing means 4 is turned on.
Supply toner.

1.2.1 As detailed above, the image forming apparatus according to the present invention includes a plurality of developer amount detection means, that is, toner sensors arranged along the longitudinal direction of a developer carrier such as a developing sleeve. death,
Based on this detection result, the drive of the toner agitation means, toner transport means, and toner replenishment means is controlled, so that the amount of toner in the developer supply device is stabilized and the amount of toner in the developer supply device is stabilized, preventing oversupply. This has the effect of preventing deterioration in image quality due to supply shortages and consistently forming high-quality images in a stable manner.

[Brief explanation of drawings]

FIG. 1 is a front sectional view of a developing device showing one embodiment of the present invention. FIG. 2 is a partially sectional plan view of the apparatus of FIG. 1; FIG. 3 is a schematic configuration diagram showing another embodiment of the present invention, in which a developing device is shown in a sectional view. 4 is a partially sectional plan view of the apparatus of FIG. 3; FIG. FIG. 5 is a schematic configuration diagram showing still another embodiment of the present invention, in which a developing device is shown in a sectional view. 6 is a partially sectional top view of the apparatus of FIG. 5; FIG. FIG. 7 is a front sectional view of a conventional developing device. FIG. 8 is a schematic diagram of the conventional image forming apparatus shown in FIG. 7, in which a developing device is shown in a cross-sectional view. 1: Image carrier (photosensitive drum) 2: Developer carrier (developing sleeve) 4: Replenishing means 5.5a, 5b, 5a', 5b': Toner sump-6a: Developer stirring means 6b = Developer conveying means 7: Hopper Figure 7 Figure 8

Claims (1)

[Claims] 1) In an image forming apparatus in which a latent image formed on an image carrier is formed into a visible image by a developing device equipped with a developer carrier that carries developer and conveys it toward the image carrier, the above-mentioned The developing device includes a conveying means for conveying the developer to the developer carrier, a stirring means for stirring the developer in the developing device, and a plurality of pieces arranged along the longitudinal direction of the developer carrier. and a detection means for detecting the amount of developer, and the image forming apparatus is characterized in that the developer transport means and the stirring means are driven and controlled by a signal from the developer amount detection means. .