JPH0358514B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention includes a hopper for storing a one-component magnetic toner, a developing magnetic sleeve rotatably supported within the hopper, and a developing magnetic sleeve for storing the one-component magnetic toner in a uniform thin layer on the magnetic sleeve. The present invention relates to a toner remaining amount detecting device in a developing device, which includes a toner layer thickness regulating member for coating the magnetic sleeve, and a voltage applying means for applying an alternating current bias voltage to the magnetic sleeve.

Conventional toner remaining amount detection devices detect the presence or absence of toner using a detection element installed at a specific location within the developing device, but the toner is replenished unevenly within the developing device and no toner is present at the detection element. Even though the amount of toner was sufficient, it was detected that there was no toner, and the machine was stopped or the operator was instructed to replenish toner. In addition, since the toner out lamp lights up even though toner has been replenished, the operator sometimes mistakenly assumes that the apparatus has malfunctioned.

The present invention has been proposed in view of the above, and is capable of accurately detecting the total amount of toner remaining in the developing device by using an AC bias voltage applied to the magnetic sleeve, and furthermore, it is possible to accurately detect the total amount of toner remaining in the developing device. An object of the present invention is to provide a toner remaining amount detection device that is free of toner.

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1 showing the first embodiment of the present invention,
A hopper 1 stores a one-component magnetic toner 2 containing a magnetic material such as iron in the center. Reference numeral 3 denotes a developing magnetic sleeve (hereinafter abbreviated as sleeve) rotatably supported within the hopper 1, and a part of its circumferential surface extends over the entire length in the longitudinal direction and extends through the opening 1 of the hopper.
It is exposed to the outside from a and is placed close to an image carrier such as a photosensitive drum (not shown). 4 is a toner layer thickness regulating member (hereinafter abbreviated as a blade) attached to the hopper 1 with a gap g1 between it and the sleeve 3;
5 is a voltage applying means for applying an AC bias voltage to the sleeve 3; 6 is a voltage applying means for applying an AC bias voltage to the blade 4; and 7 is a detector disposed close to the sleeve 3 and rotatably supported in the hopper 1. The conductor is a coiled metal, for example, as shown in FIG. This sensing conductor is rotationally driven in the direction of the arrow by a drive mechanism (not shown) provided outside the hopper. In this case, it is preferable that the coil spacing d is set to a value of 5 mm or more to prevent clogging of toner.

With the above configuration, the sleeve 3 is attached to the sensing conductor 7.
An induced voltage is generated based on the AC bias voltage applied to the This induced voltage changes as the magnetic permeability changes depending on the amount of toner between the sleeve 3 and the sensing conductor 7. Now, if we compare the sleeve 3 and the detection conductor 7 to a radio wave generation source and an antenna, since iron ferrite (toner) has entered therein, the detection conductor 7 will change due to changes in this ferrite (toner).
The induced voltage generated in the change changes. A remaining toner amount detection circuit, which will be described later, is connected to this detection conductor.

In this case, when the amplitude and frequency of the bias voltage applied to the developing sleeve 3 changes, the voltage induced in the sensing conductor 7 changes, so the amplitude and frequency of the bias voltage are controlled to be constant. or,
The closer the distance between the detection conductor 7 and the developing sleeve is, the higher the detection accuracy will be, but since there is a possibility that the toner will harden, it is desirable to keep them separated to some extent.

FIG. 3 shows another embodiment of the present invention, in which a metal auger roll-shaped detection conductor 7 is installed in the hopper 1.
0 and a stirring member 8 are each supported rotatably in the direction of the arrow, and the rotation of the sensing conductor and the stirring member causes the toner 2 to move in the directions of arrows a and b shown in FIG. The detection conductor 70 is connected to a remaining toner amount detection circuit (not shown).

FIG. 5 is a block diagram showing an example of a remaining toner amount detection circuit, and FIG. 6 is a specific circuit diagram thereof. In FIG. 5, 10 is a control signal input terminal, 11
is an AC power supply, 12 is a developing bias voltage generator, 1
3 is a rectifier circuit, 14 is a reference voltage generator, 15 is a comparison circuit, 16 is a gate circuit, 17 is a holding circuit, 1
8 is a display.

When a control signal is input to the input terminal 10, a developing bias is applied to the sleeve 3, and an AC voltage corresponding to the remaining amount of toner 2 is induced in the detection conductor 7.

The induced voltage is converted into a direct current by the rectifier circuit 13 and input to the comparator circuit 15 . The comparison circuit 15 compares the output voltage of the reference voltage generator 14 and the output voltage of the rectifier circuit 13, and inputs the result of the magnitude determination to the gate circuit 16. A control signal is input to the other terminal of the gate circuit 16, and the remaining amount of toner is low.
When the control signal is being output, the signal is output to the holding circuit 17, and the display 18 is lit to indicate that the remaining amount of toner is low. The holding circuit 17 is provided to display that the remaining amount of toner is low even when the control signal is not output.

This will be explained in more detail using the detailed circuit shown in FIG. 6th
In the figure, parts having the same functions as those in FIG. 5 are given the same numbers.

An AC high voltage is applied to the sleeve 3 by a control signal input to the terminal 10, and an AC voltage corresponding to the remaining amount of the toner 2 is induced in the detection conductor 7. The voltage induced in the sensing conductor is variable resistor VR1
After dividing the voltage with 1, rectify with diode D11,
The DC voltage V _S is obtained by smoothing with the capacitor C11.
The DC voltage V _S is input to the non-inverting input terminal of the operational amplifier OP2. The output voltage V _DD of the stabilized power supply 19 is connected to the inverting input terminal of the operational amplifier OP2 through the resistor R1.
2. The voltage is divided by the variable resistor VR12 and applied. The reference voltage is varied by variable resistor VR12,
The amount of detection can be changed.

When there is a large amount of toner remaining, operational amplifier OP2 outputs (+) voltage to the output terminal and transistor TR1
1 turns on. On the other hand, since the control signal is input to the inverter INV2, TR12 is off. Therefore, the voltage V _DD is the diode D
12, grounded via transistor TR12,
The rectifier switching element SCR1 is turned off, and the light emitting diode LED2 does not light up.

When the remaining amount of toner becomes low, TR11 turns off.
When the control signal is output, TR12 is also off and the voltage V _DD is connected to diode D14 and resistor R17.
is grounded through, turns on SCR1 and turns on LED2.
lights up. LED2 continues to light up even if the control signal is no longer output due to the action of SCR1.

When the toner supply port (not shown) is opened, the switch SW is opened and the SCR1 is turned off. After toner is replenished, the next time a control signal is output, the transistor TR11 is turned on and the light emitting diode LED2 remains off. 1
9 is a power supply terminal 20 via the power switch SW
A stabilized power supply connected to the

In the present invention, the toner remaining amount detection conductor has a coil shape or an auger roll shape, which is effective for agitating the toner, and is rotated by a driving means, so that the toner in the toner storage container can be easily absorbed by the detection conductor itself. This prevents crosslinking of the toner and allows accurate detection of the amount of toner remaining in the toner storage container.

[Brief explanation of drawings]

FIG. 1 is a side view showing an outline of a developing device equipped with the toner remaining amount detecting device of the present invention, FIG. 2 is a front view of a conductor member applied to this toner remaining amount detecting device, and FIG.
4 is a side view showing an outline of a developing device equipped with another example of the toner remaining amount detection device of the present invention; FIG. 4 is a front view of a conductor member and stirring member applied to this toner remaining amount detection device; FIG. 5 is a block diagram of the remaining toner amount detection circuit, and FIG. 6 is a specific circuit diagram thereof. 1 is a hopper, 2 is a one-component magnetic toner, 3 is a sleeve, 4 is a blade, 5 and 6 are voltage application means, 7
8 is a conductor member, and 8 is a stirring member.

Claims (1)

[Claims] 1. A container for storing one-component magnetic toner, a developing sleeve rotatably supported within the container, a toner layer thickness regulating member for applying the one-component magnetic toner in a uniform thin layer onto the developing sleeve, and In a developing device equipped with a voltage applying means for applying an AC bias voltage to the developing sleeve, a coil-shaped or auger roll-shaped sensing conductor is provided in the container in parallel with the developing sleeve, and the sensing conductor is driven by a driving means. is rotated to stir the toner in the container, and the remaining amount of toner is detected based on the magnitude of the voltage induced in the detection conductor via the one-component magnetic toner using an AC bias voltage applied to the developing sleeve. A toner remaining amount detection device characterized by detecting.