JPH0535097A - Residual toner detecting device - Google Patents

Abstract

PURPOSE:To detect residual toner and simultaneously, the presence of a developing unit, in a residual toner detecting device detecting the residual toner inside the developing unit attachably/detachably provided on an electrophotographic device. CONSTITUTION:The residual toner detecting device has a constitution so as to be provided with a toner sensor composed of light emitting and receiving elements disposed on the main body of the electrophotographic device, a toner detecting window 9 disposed on the developing unit, 2 member 10 removing toner sticking to the toner detecting window 9, and a means detecting/ discriminating the output pattern of the toner sensor, and the presence of the toner 3 and the developing unit can be detected with three patterns of the output of the toner sensor.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner remaining amount detecting device for detecting a remaining amount of toner in a developing unit which is detachably attached to an electrophotographic apparatus.

[0002]

2. Description of the Related Art Generally, in an electrophotographic apparatus, a developing unit containing a toner, which is a developer, is detachably attached to the main body of the electrophotographic apparatus. Since the developing device unit is detachable, the presence or absence of the developing device unit is detected by a micro switch to prevent the printing operation from being started when the developing device unit is not installed. Further, when the toner remaining amount detecting device detects that the toner remaining amount is low and the display panel indicates that the toner needs to be replenished, the developer unit containing the toner is replaced.

A conventional toner remaining amount detecting device will be described below. As shown in FIG. 3, toner conveying members 1a, 1b, 1c and 1d made of wire such as stainless steel are rotatably supported in the direction of the arrow at both ends of the developing bat 2 by bending both ends thereof in a rectangular shape. There is. Toner transport member 1a
1 to 1d prevent blocking of the toner 3 in the developing device unit and convey the toner 3 onto the replenishing roller 4. Replenishing roller 4 in which a conductive layer such as urethane is layered on the outer peripheral surface of a metal such as stainless steel.
Is rotatably supported by the developing butt 2 at both ends rotatably in the direction of the arrow, and replenishes the toner 3 conveyed by the toner conveying member 1a to the surface of the developing roller 5.

The developing roller 5 is made of a metal such as stainless steel, and a conductive member such as silicon or urethane is formed in layers on the outer peripheral surface of the developing roller 5. The developing roller 5 is rotatably supported at both ends of the developing bat 2 in the arrow direction. There is. A toner control plate 6 made of a conductive material such as silicon or urethane forms a charged and thin layer state on the toner 3 on the surface of the developing roller 5, and contacts the photoconductor 8 to form an electrostatic latent image on the photoconductor 8. The toner 3 is attached to the portion where the mark is formed to form a toner image.

The piezoelectric toner sensor 7 provided in the developing device unit determines the presence / absence of the toner 3 based on the difference in the sensor output waveform. If the toner 3 is not present, it is displayed on the display panel and the developing device unit is replaced. Give instructions.

As shown in FIG. 4, the piezoelectric toner sensor 7
Is a piezoelectric element 11, a transistor 12, and resistors 13 to 1
In a kind of oscillator configured by 5, when an operating voltage is applied between the terminals a and c, the terminal b is changed according to the toner amount on the sensor detection surface.
The amplitude of the output voltage changes, and the output waveform changes according to the remaining amount of the toner 3 on the sensor detection surface.

[0007]

However, in the above-mentioned conventional structure, since the toner 3 is replenished by replacing the developing device unit, the piezoelectric toner sensor of the replaced developing device unit is not reused, but is replaced. There is a problem that the cost of the developing device unit is increased, and the cost of the micro switch itself for detecting the presence or absence of the developing device unit is higher than that of electric circuit parts such as IC.

The present invention solves the above-mentioned conventional problems, and an object of the present invention is to provide a toner remaining amount detecting device for detecting the toner remaining amount and the presence / absence of a developing unit.

[0009]

In order to achieve this object, a toner remaining amount detecting device of the present invention comprises a toner sensor formed of a light emitting element and a light receiving element provided in a main body of an electrophotographic apparatus, The toner detection window provided in the developing unit, the toner removing member attached to the toner detecting window, and the output pattern of the toner sensor are detected, and the presence or absence of toner and the presence or absence of the developing unit are detected based on the output pattern. It is provided with a means for determining.

[0010]

With this structure, in the case of no toner, light is made incident on the inside of the developing unit through the detection window which is transparent from the light emitting element, and is received by the light receiving element outside the developing unit from the facing detection window, In addition, the toner removing member shields the detection window at regular intervals. When toner is present, the light that has entered the developing unit is blocked by the toner and is not received by the light receiving element.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1 showing an embodiment of the present invention, the same parts as those of the conventional example are designated by the same reference numerals and the description thereof will be omitted.

As shown in FIG. 1, a toner detection window 9 in which a transparent resin is fitted in a hole on the side surface of the developing device unit is provided on the opposite side surface together with the same toner detection window 9. A light emitting element and a light receiving element of a toner sensor are arranged in the main body of the electrophotographic apparatus, and when the developing device unit is mounted, the two toner detection windows 9 are aligned with the positions of the light emitting element and the light receiving element, respectively. (Not shown). Light entering the developing device unit from the light emitting element through the toner detecting window 9 is received by the light receiving element through the facing toner detecting window 9 unless there is a shield in the developing device unit. The removing member 10 attached to the toner conveying member 1a and scraping off the toner 3 adhering to the toner detecting window 9 is formed of an elastic member such as urethane and rotates in conjunction with the toner conveying member 1.

In this embodiment, the toner detection window 9 is arranged below the rotation range of the first toner carrying member 1a, and the removing member 10 is attached to the first toner carrying member 1a. The toner 3 in the developing unit is the toner transport member 1
Since it is carried forward by the rotation of a to 1d, the detection position is arranged within the rotation range of the first toner conveying member 1a in order to perform accurate detection.

The operation of detecting the remaining amount of toner and detecting the presence / absence of a developing unit in the remaining toner amount detecting device constructed as described above will be described.

The output of the toner sensor consisting of the light emitting element and the light receiving element is connected to the input port of the central processing unit for monitoring the operation of the entire system. The toner sensor is configured to output a logic level "1" when the light receiving element receives the light and outputs a logic level "0" when the light receiving element does not receive the light. When the toner 3 is sufficiently contained in the developing device unit, the light entering the developing device unit from the light emitting element through the toner detecting window 9 is blocked by the toner 3 and cannot be received by the light receiving element. Outputs a logic level "0". The time chart of the toner sensor output in this case is as shown in FIG.

Toner 3 is consumed and two toner detection windows 9 are used.
When there is no toner on the straight line connecting the two, the light receiving element of the toner sensor receives the light and outputs the logic level "1". However, since the toner detection window 9 is shielded at a constant cycle by the rotation of the removing member 10, the output of the toner sensor has a pulse waveform as shown in FIG.

Since the toner removing member 10 is interlocked with the first toner carrying member 1a, its cycle is set to 500 msec, which is the same as the first toner carrying member 1a. Therefore, the cycle of the waveform in FIG. 2B is 500 mse.
c. Further, in this embodiment, the time period for which the removing member 10 shields the toner detection window 9 is set to 500 msec. When the developing unit is not installed in the main body of the electrophotographic apparatus, since there is no shield between the light emitting element and the light receiving element of the toner sensor, the logic level "1" is always output. 2 (C).

As described above, the output from the toner sensor has three patterns. The conditions for determining the presence / absence of toner and the presence / absence of a developing unit are described below. If the time that the toner sensor output keeps the logic level "1" is T, 400m
If sec ≦ T ≦ 500 msec, it is determined that there is no toner and a developing device unit is present. Also, T> 500 ms
In the case of ec, it is determined that there is no developing unit. If T <400 msec other than these two conditions, it is determined that the toner is present and the developing unit is present. These determinations are made in a state where the driving force is transmitted to the developing device unit.

As described above, according to this embodiment, the toner sensor composed of the light emitting element and the light receiving element, the toner detecting window 9 provided in the developing unit, and the toner detecting window 9 are provided.
By providing a removing member 10 for removing the toner 3 adhering to the developing device and a means for determining the presence or absence of the toner 3 and the presence or absence of the developing device unit based on the output pattern of the toner sensor, The presence / absence can be detected at the same time as the presence / absence of the toner 3, and the presence / absence of the toner and the presence / absence of the developing device unit are determined based on the duration of the toner sensor output state.

[0021]

As is apparent from the above description of the embodiments, the present invention is directed to a toner sensor including a light emitting element and a light receiving element, a detection window provided in a developing unit, and a detection window. An excellent toner remaining amount detecting device capable of detecting the remaining amount of toner and detecting the presence / absence of a developing device unit by a structure provided with a member for removing the toner adhering to the toner and a means for detecting and determining the output pattern of the toner sensor. Can be realized.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a concept of a main part of a developing unit in which a toner remaining amount detecting device according to an embodiment of the present invention is arranged.

FIG. 2 is a time chart showing an output pattern of a toner sensor of the toner remaining amount detection device.

FIG. 3 is a cross-sectional view showing a concept of a main part of a developing device unit provided with a conventional toner remaining amount detecting device.

FIG. 4 is a circuit diagram of a piezoelectric toner sensor of the remaining toner amount detecting device.

[Explanation of symbols]

 1a toner conveying member 4 replenishing roller 5 developing roller 9 toner detection window 10 removing member

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshihiro Mizoguchi, 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (1)

Claim: What is claimed is: 1. An electrophotographic apparatus having a developing device unit accommodating toner, which is a developer, which is detachably provided, the electrophotographic apparatus including a light emitting element and a light receiving element. The toner sensor provided, the toner detection window provided in the developing unit, the toner removing member attached to the toner detection window, the output pattern of the toner sensor are detected, and the output pattern is detected. Based on the above, a toner remaining amount detecting device having means for determining the presence or absence of the toner and the presence or absence of the developing device unit.