JPH047577A - Toner rest detecting device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a toner remaining amount that detects the remaining amount of toner stored in a toner storage portion in a developing device of an image forming apparatus using electrophotography. Regarding a detection device.

[Prior Art] Conventionally, the surface of a photoreceptor drum whose surface is formed of a photoconductor is exposed to light to form an electrostatic latent image, toner is attached to this latent image and developed, and the toner is applied to recording paper. Image forming apparatuses such as electronic copying machines and laser beam printers are known that utilize so-called electrophotography in which images are transferred and fixed using a fixing device.

The developer used in electrophotography is a two-component toner in which a non-magnetic toner and a magnetic carrier are mixed in a predetermined ratio, and a carrier is not required by adding a charge control agent to the magnetic toner. There are two types of two-component toners. Recently, there is also a so-called 1.5-component development method in which a -component toner is used, a magnetic carrier is attached to a developing roller in advance, and development is carried out by a magnetic brush method via the carrier.

In the developing device, the toner consumed in the developing operation must be sequentially replenished into the toner storage unit. Therefore, it is necessary to know the amount of toner remaining in the toner storage unit.

When using two-component toner, only the toner is consumed during the development process and the ratio of carrier to toner changes, so a magnetic permeability sensor is used to detect the carrier density in the developer. There are many things.

On the other hand, those that use -component toner (including 1 and 5-component development) are far more effective than those that use two-component toner because they simply need to be replenished when the toner in the toner storage unit runs low. A pressure sensor is provided below the toner storage portion, and the remaining amount of toner is determined by detecting the toner pressure.

[Problems with the prior art] However, even when using -component toner,
There is a problem in that the pressure sensor detects the presence or absence of toner at a position corresponding to the pressure sensor, and the remaining amount of toner in the entire toner storage unit cannot be determined. In other words, the amount of toner consumed in the longitudinal direction of the developing device varies depending on the image forming pattern, and therefore the amount of toner remaining in the toner storage section also varies depending on the location, or whether it is placed in a predetermined position. The pressure sensor outputs a toner present signal if toner is present at a position corresponding to the pressure sensor, regardless of other parts, and outputs a toner absent signal if toner is not present.

[Object of the Invention] In view of the above-mentioned circumstances, an object of the present invention is to provide a remaining toner amount detection device that can determine the amount of remaining toner in the entire toner storage unit.

[Means for Solving the Problems] In order to achieve the above object, the toner remaining amount detection device according to the present invention includes a stirring means disposed in a toner storage section, a driving means for moving and driving the stirring means, and a driving means for driving the stirring means. The device includes a load detection means for detecting a load on the means, a display means for displaying an insufficient amount of toner remaining, and a remaining toner amount determination means for determining the remaining amount of toner based on the load detection information from the load detection means. and a control device that drives and controls the display means when the amount determining means determines that the remaining amount of toner is low.

[Embodiments of the invention] Next, the present invention will be explained in detail based on the drawings.

FIG. 1 is a block diagram of a remaining toner amount detection device according to the present invention, and FIG. 2 is a cross-sectional view of a developing device to which one embodiment of the device is applied.

The illustrated developing device 1O has a substantially cylindrical toner storage section 12 formed by a housing 11, and a toner storage section 12 is placed in the center of the toner storage section 12 to agitate the toner inside the toner storage section 12 and transfer it to a developing roller 13, which will be described later. A scraper 20 serving as an agitating means for supplying toner is inserted through the toner storage section 12, and a developing roller 13 is disposed diagonally below the toner storage section 12. Further, a toner cartridge 14 is installed at a symmetrical position sandwiching the developing roller 13 and the toner storage section 12 (diagonally above the toner storage section 12).

The developing roller 13 is connected to the side plate 11A of the housing 11 at both ends.
The peripheral surface thereof is exposed through an opening 11B formed in a corresponding portion of the housing 11, and the opening 1
The held toner is supplied to the surface of a photosensitive drum (not shown) via 1B. Incidentally, reference numeral 16 denotes a cutting plate that regulates the amount (height) of toner adsorbed on the surface of the developing roller 13.

As shown in FIG. 3, a schematic perspective view of the scraper 20, the rotating shaft portion 21 is bent into a crank shape at intervals of 1206 times, which divides the rotational circumference into three, and three stirring portions 2 are formed.
2... are formed, and a plate 23 is attached to each of the stirring parts 22.... It is rotatably held by the rotating shaft portions 21.21 at both ends or the side plate 11A of the housing 11, and is driven by a DC motor 25 as a driving means via a gear 24 fixed to one end.
It is configured to be rotationally driven at the speed of rotation.

The rotation locus of the tip of the plate 23 of the scraper 20 is set to be as close to the bottom surface of the toner storage section 12 as possible, and the toner in the toner storage section 12 is removed from the plate 23.
The toner in the toner storage section 12 acts as a rotational resistance to the rotation of the sprayer 20.

The DC motor 25 that rotationally drives the soup scraper 20 includes
A load detection means 30 is connected as shown in the first diagram.

The load detection means 30 has a circuit diagram as shown in FIG.
Consisting of a current-voltage conversion circuit 31 and a reference voltage comparison circuit 32, it converts the current value flowing through the DC motor 25 into a voltage value and inputs this voltage value from the non-inverting input terminal of the comparator 33. The reference voltage is input from the inverting input terminal. Note that the reference voltage can be variably adjusted by operating an interposed variable resistor BR. In the load detection means 30, when the voltage value corresponding to the load of the DC motor 25 is larger than a reference value (reference voltage value), the output becomes fi'LOW, il as shown in FIG.

That is, according to the above configuration, the toner in the toner storage section 12 acts as a rotational resistance to the sprayer 20 (DC motor 2).
5), and when the rotational load exceeds a predetermined amount, the output signal from the load detection means 30 is IrLOW,
il, and depending on the setting of the reference voltage value, the output from the load detection means 30 when the remaining amount of toner reaches a predetermined amount (that is, when the rotational resistance of the spray flapper 20 due to toner reaches a predetermined value) It is possible to set the signal to be li'LOW or il.

The output from the load detecting means 30 is transmitted to the control device 4 which is equipped with a toner remaining amount determining means 41 as shown in the first diagram and is connected to a display means 50 such as an alarm for warning of insufficient toner remaining amount.
The control device 40 uses the toner remaining amount determining means 41 to determine the remaining toner amount based on the input information from the load detecting means 30, and based on the result of this determination, the remaining toner amount is determined. The display means 40 is driven and controlled. Further, although a detailed explanation is omitted, the control device 40 controls the rotational drive of the spray wrapper 20 (i.e., the rotational drive control of the DC motor 25), etc. based on commands from the control section of the entire image forming apparatus including the developing device 11. It also controls the operation of the ground.

Next, the determination of the amount of remaining toner and the drive control of the display means 40 by the control device 40 will be explained according to the flowchart shown in the sixth figure.

First, when a drawing start command signal is input from the control unit of the entire image forming apparatus (Sl), the sprayer 20 starts rotating (S2), and a timer is set (S3).
) Time: Start measuring t (S4).

Then, it is checked whether or not the Ii'LOWJl signal is input from the load detection means 30 (SS), and if the IrLOWJ] signal is not input during a predetermined period of time: t=2 seconds, the rotating load of the Sprayer 20 is detected. Since the amount is less than a predetermined value, it is determined that the amount of toner is insufficient, and the display means 50 is driven and controlled to display the absence of toner (S7, S9).

On the other hand, when the FLOW and Jl signals are input from the load detection means 30, it is determined that a predetermined amount or more of toner is present in the toner storage section 12, and from then on, the load detection means 30 in S3 to S5 described above This signal detection is repeated until the drawing is completed.

Here, during the predetermined time, t-2 seconds, ff'LOWJ
The meaning of detecting the presence or absence of the I signal is that in this embodiment, the rotation speed of the soup scraper 20 is set to 1 rotation every 2 seconds as described above, and the speed exceeds a predetermined value even once during this 1 rotation of 2 seconds. If there is a rotational load (if the ff'LOW signal is input), it is determined that there is sufficient toner remaining in any one of the three agitation units 22.

At the end of drawing (S6), the rotation of the spray scraper 20 is stopped (S8) and the control ends.

In the above embodiment, the stirring means is the sprayer 2 which stirs the toner and supplies the toner to the developing roller 13.
0, and detects the rotational load of the spray scraper 20. However, the present invention is not limited to this, and it goes without saying that an independent stirring means may be provided for detecting the remaining amount of toner. Nor.

[Effects of the Invention] As described above, according to the toner remaining amount detection device according to the present invention, it is possible to grasp the entire amount of toner remaining in the toner storage unit, and it is possible to issue a toner remaining amount warning with high accuracy. It is something that can be done.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of the toner remaining amount detection device according to the present invention, FIG. 2 is a cross-sectional view of a developing device to which the same is applied, and FIG.
4 is a schematic perspective view of the scraper, FIG. 4 is a circuit diagram of the load detection means, FIG. 5 is a chart showing the relationship between load fluctuations and the output from the load detection means, and FIG. 6 is a control flow chart. DESCRIPTION OF SYMBOLS 10...Developing device 20...Sprayer (stirring means) 25...Motor (driving means) 30...Load detection means 40...Control device 41...Toner remaining amount determination means 50... Display means diagram

Claims (1)

[Scope of Claims] A stirring means disposed in a toner storage section, a driving means for moving and driving the stirring means, a load detecting means for detecting a load on the driving means, and a display means for indicating insufficient amount of toner remaining. and a remaining toner amount determining means for determining the remaining amount of toner based on the load detection information from the load detecting means, and when the remaining toner amount determining means determines that the remaining amount of toner is low, the display means A toner remaining amount detection device comprising: a control device for driving and controlling; and a toner remaining amount detection device.