JPH10260577A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device of electrophotographic system capable of easily detecting residual toner in a developing device, even in the case of the magnetic toner, needless to say the non-magnetic toner. SOLUTION: This device is constituted with a paddle 911 for agitating the toner in the developing device 91. In this case, by providing a photointerrupter, which is constituted of a light emitting part 931 and the light receiving part 932 capable of detecting the change of a transmitted light quantity in company with agitation of the toner by a paddle 911 in the developing device 91, and the detected output of the light receiving part 932 of the photointerrupter is processed by a CPU so as to detect the residual toner in the developer 91.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus utilizing an electrophotographic system, and more particularly to an image forming apparatus capable of detecting a remaining amount of toner in a developing unit.

[0002]

2. Description of the Related Art In an electrophotographic image forming apparatus, toner is selectively attracted to an electrostatic latent image formed on a photoreceptor, developed as a toner visible image, transferred to a sheet, and then heated.・ Pressurize and fix on paper. The toner is selectively attracted to the photoreceptor by a developing device. Information on how much toner remains in the developing device is important information for maintenance management.

Incidentally, toners used in the electrophotographic system include a magnetic toner and a non-magnetic toner. In the case of a magnetic toner, the remaining amount of the toner can be detected by magnetic detection. However, in the case of targeting non-magnetic toner, conventionally, only the presence or absence of toner has been detected by a photoelectric sensor.

[0004]

In the prior art as described above, in an electrophotographic image forming apparatus using a non-magnetic toner, only the presence or absence of the toner in the developing device could be detected. The user could not prepare a spare toner in anticipation that the toner replacement time was approaching. Therefore, there has been a problem that only the spare toner is always prepared irrespective of the remaining amount of toner or a new toner is ordered after the toner runs out.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and an electrophotographic apparatus capable of easily detecting the remaining amount of toner in a developing device not only for a non-magnetic toner but also for a magnetic toner. It is an object of the present invention to provide an image forming apparatus of a system.

[0006]

An image forming apparatus according to the present invention is an image forming apparatus provided with an agitating device for agitating toner in a developing device. It is characterized by comprising a photoelectric sensor capable of detecting a change in the amount of transmitted light, and arithmetic means for calculating the remaining amount of toner in the developing device based on the detection output of the photoelectric sensor.

In such an image forming apparatus of the present invention, the calculation means determines not only the presence or absence of toner in the developing device but also the remaining amount of toner based on the detection output of the photoelectric sensor.

In the image forming apparatus according to the present invention, in the above-described configuration, the calculating means determines the remaining amount of toner in the developing device based on an average value of a predetermined number of past detection outputs of the photoelectric sensor. Features.

In such an image forming apparatus of the present invention, since the remaining amount of toner in the developing device is obtained based on an average value of a predetermined number of times in the past, a stable result can be obtained.

Further, in the image forming apparatus according to the present invention, in the above-described configuration, the calculating means determines the remaining amount of toner in the developing device based on the number of times of detection output of the photoelectric sensor which is equal to or less than a predetermined value in the past predetermined number of times. It is characterized by what it did.

In such an image forming apparatus of the present invention, since the remaining amount of toner in the developing device is obtained based on the average value of a predetermined number of times in the past, a stable result can be obtained.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the drawings showing the embodiments. FIG. 1 is a functional block diagram of a facsimile apparatus showing one configuration example of an embodiment in which an electrophotographic image forming apparatus according to the present invention is applied to a facsimile apparatus, and a schematic diagram showing a configuration example of the image forming apparatus of the present invention. FIG.

In FIG. 1, reference numeral 1 denotes a CPU (central processing unit) functioning as a control unit of the facsimile apparatus, and a ROM (Read) preliminarily storing a program for controlling the operation of the entire facsimile apparatus. Only Memor
y) 2 and a RAM (Random Access Memory) 3 functioning as a storage unit for storing data required for control by the CPU 1 or data that needs to be temporarily stored during operation. In the ROM 2, a look-up table 201 or 202 described later is stored in an appropriate area.

The CPU 1 has an NCU (Network Control Unit).
nit) 4 and modem 5 are connected. NCU 4 is CPU 1
, And controls the connection between the line L and the facsimile machine, and has a function of transmitting a dial pulse corresponding to the telephone number of the communication partner and a function of detecting an incoming call. The line L is connected to a general public telephone line (not shown). The modem 5 modulates and demodulates the transmission / reception data, specifically, modulates the transmission data into an audio signal.
Sends out to line L via NCU 4 and vice versa
The audio signal received via U4 is demodulated into a digital signal.

The CPU 1 is further connected to a reading unit 6, an image memory 7, a codec 8, a recording unit 9, an operation unit 10, a display unit 11, and the like.

The reading section 6 reads a document image using a scanner such as a CCD image sensor. The image memory 7 stores image data read by the reading unit 6 and image data received from outside via the line L and the modem 5. The codec 8 encodes the image data to be transmitted and decodes the received image data. The recording unit 9 is an image forming apparatus according to the present invention, which will be described in detail later. Function as a means for performing The operation unit 10 includes ten keys for inputting numbers such as telephone numbers, one-touch keys, abbreviated keys, operation keys for instructing various operations, and the like. The display unit 11 outputs various kinds of information such as the telephone number input by the operation of the operation unit 10 and the remaining amount of toner in the developing unit of the recording unit 9 by soft copy and displays them.
It is composed of an RT display or an LCD (Liquid Crystal Display).

Next, the recording section 9 which is an image forming apparatus of the present invention will be described with reference to the schematic diagram shown in FIG.

The recording unit 9 is specifically connected to the CPU 1 by an interface (I / O) 901 and a codec 902.
/ O 901 is mainly responsible for control signals relating to the mechanical operation of the recording unit 9, and the codec 902 is responsible for transmitting and receiving image data for image formation.

The recording unit 9 itself has a developing unit 9 as a main component, similarly to a conventional electrophotographic image forming apparatus.
1, a photosensitive drum 92, a charging brush 93, a transfer roller 94, and the like. In the present embodiment, the photosensitive drum
LED array as a means to form an electrostatic latent image on 92
95, but other methods such as forming a latent image by projecting a laser beam on the photosensitive drum 92, LED
A method of projecting a light beam by a shutter may be used. Note that the photosensitive drum 92 and the transfer roller 94 are opposed to each other in a state of being pressed.

Reference numeral 96 denotes a paper cassette in which paper is stored, 97 denotes a pickup roller for taking out one of the uppermost layers of the paper stored in the paper cassette 96, 98
Is a solenoid that connects and disconnects the rotational driving force of the motor M to the pickup roller 97, and 99 detects that one sheet picked up from the paper cassette 96 by the pickup roller 97 reaches a predetermined position immediately before the developing device 91. 100 denotes a fixing roller, and 100 denotes a fixing roller.

A dashed line indicated by reference numeral 101 indicates a paper transport path from the paper cassette 96 to the fixing roller 100.

CPU 1 is connected to solenoid 98 via I / O 901.
Thus, a control signal S1 for disconnecting the motor M from the pickup roller 97 is provided. Paper sensor 99 to CPU 1
Is supplied with an on / off signal, that is, a detection signal S2 indicating whether or not the arrival of the sheet is detected via the I / O 901.

The developing device 91 includes a plurality of paddles 911 for stirring the toner contained therein, a toner sensor 910 described in detail later, and a device for selectively adsorbing the toner to the photosensitive drum 92. It is composed of rollers for transporting.

Reference numeral 102 denotes an analog / digital (hereinafter, referred to as A / D) converter.
The analog detection signal S3 from the toner sensor 910 provided in the developing device 91 is converted into a digital detection signal S4.
This digital detection signal S4 is given to the CPU 1 via the I / O 901.

In the recording section 9 having such a configuration, when the control signal S1 is given from the CPU 1 via the I / O 901, the rotational driving force of the motor M is connected to the pickup roller 97 and One sheet of paper is picked up by the pickup roller 97 and transported to the paper sensor 99. When the paper sensor 99 detects the arrival of the paper and outputs the detection signal S2, the CPU 1 causes the codec 902 to output image data to the LED array 95 at a predetermined timing. As a result, the photosensitive drum 92 rotates while an electrostatic latent image is formed on the surface thereof, and the toner is selectively adsorbed by the developing device 91 to form a toner visible image.

On the other hand, the sheet is further conveyed from the position of the sheet sensor 99 to a position where the photosensitive drum 92 and the transfer roller 94 are opposed to each other and sent between them, and a toner visible image is transferred to the surface thereof. Further, the toner image is fixed by being heated and pressed by the fixing roller 100.

FIG. 2 is a schematic view showing the toner sensor 910 and the developing device 91 near the portion where the toner sensor 910 is mounted.
The toner sensor 910 has two convex portions 921 and 922 formed therein. One convex portion 921 has a light emitting portion 931 of a photo interrupter as a photoelectric sensor, and the other convex portion 922 has a light receiving portion 932 of a photo interrupter. Are respectively built-in.

On the other hand, in the lower part of the developing device 91, two concave portions 941 and 942 are located inward so that the two convex portions 921 and 922 of the toner sensor 910 just fit in from the outside of the developing device 91. It is formed. Note that at least the opposing portions of these concave portions 941 and 942 are formed of a transparent member.
In addition, one of them passes through the opposing gap 940 between the concave portions 941 and 942 as the plurality of paddles 911 rotate.

Accordingly, with the rotation of the paddle 911, the toner existing in the gap 940 between the concave portions 941 and 942 is scraped out from the gap 940 between the concave portions 941 and 942. However, when the toner is deposited on at least the tops of the two concave portions 941 and 942 inside the developing device 91, the two concave portions
The opposing gap 940 between 941 and 942 is immediately filled with toner, but the time depends on the remaining amount of toner inside the developing device 91.

On the other hand, the light emitted from the light emitting portion 931 of the photo interrupter is transmitted to both the concave portions 941 and 942 formed of a transparent member.
The light receiving section 93 of the photo interrupter is
2, the gap between the two concave portions 941 and 942
Presence of toner at 940, more specifically paddle 911
After the toner is scraped out from the gap 940 between the two concave portions 941 and 942, the toner is again
The time until zero is filled will be detected. However, the detection state of the light receiving unit 932 is also changed depending on the presence or absence of the developing device 91 itself.

Next, the flowchart of FIG. 3 showing the processing procedure of the CPU 1 based on the detection result by the toner sensor 910 of the electrophotographic image forming apparatus as the apparatus of the present invention having the above-described configuration, and the appropriate operation of the RAM 3 This will be described below with reference to the schematic diagram of FIG. 4 showing the contents of the look-up table stored in the storage area.

The toner sensor 910 always emits light from its light emitting portion 931. Therefore, the paddle 911 has the two concave portions 941 and 942
When the toner passes through the opposed gap 940, the toner is scraped out of the gap 940. Thereafter, the light receiving unit 932 receives the light emitted from the light emitting unit 931 for a time corresponding to the remaining amount of the toner in the developing unit 91.

First, the CPU 1 converts the detection signal of the toner sensor 910 after the paddle 911 has passed through the facing gap 940 between the two concave portions 941 and 942 into A / A based on the time measurement result of a timer (not shown).
The value digitized by D 102 is fetched at regular intervals (step S11), and an average value of a predetermined number (hereinafter, referred to as n) is obtained (step S12). Based on this result, CPU1
Refers to the look-up table 201 in the ROM 2 (step S13), and determines whether the remaining amount of toner is equal to or less than a predetermined amount (step S14).

FIG. 4 is a schematic diagram showing an example of the contents of the look-up table 201. Each value of the detection signal S4 of the toner sensor 910 after being digitized by the A / D 102, which is obtained in advance by an experiment. And the remaining amount of toner in the developing unit 91
(Unit: g) is stored.

If the remaining amount of toner is not less than the predetermined amount,
("NO" in step S14), the CPU 1 proceeds to step S11.
To return to the toner sensor 9 after passing the next paddle 911.
The above processing is repeated by taking in 10 detection signals S4. On the other hand, if the remaining amount of toner is equal to or less than the predetermined amount ("YES" in step S14), the CPU 1 displays a message on the display unit 11 to alert the user to supply toner (step S15). .

In the above embodiment, step S15
Although the presence or absence of toner is displayed on the display unit 11, the detected remaining amount of toner may be displayed as a specific numerical value. Display to prepare the toner of
Further, a display requesting replacement may be performed when the amount of remaining toner is low.

FIG. 5 is a flowchart showing another example of the processing procedure by the CPU 1, and FIG.
FIG. 4 is a schematic diagram showing contents of a lookup table stored in an appropriate storage area of FIG. Hereinafter, other processing procedures of the CPU 1 will be described with reference to these drawings.

First, in the CPU 1, the paddle 911 has the two concave portions 941,
The detection signal of the toner sensor 910 after passing through the opposed gap 940 of 942 is read by the A / D 102 as a digitized value (step S21). Then, the number of times (hereinafter, referred to as m) that is equal to or less than a predetermined value (hereinafter, referred to as Th) is obtained from among the detection results of the past predetermined number of times (hereinafter, referred to as n times) (step S2).
2). Based on the result, the CPU 1 refers to the look-up table 202 in the ROM 2 (step S23) and determines whether the remaining amount of toner is equal to or less than a predetermined amount (step S24).

FIG. 6 is a schematic diagram showing an example of the contents of the look-up table 202. When the detection signal S4 from the toner sensor 910 is acquired n times in advance by an experiment, the value is not more than a predetermined value Th. M
The correspondence with the remaining amount of toner (unit: g) in 91 is stored in advance.

When the remaining amount of toner is not less than the predetermined amount,
("NO" in step S24), the CPU 1 proceeds to step S21.
To return to the toner sensor 9 after passing the next paddle 911.
The above processing is repeated by taking in 10 detection signals S4. On the other hand, if the remaining amount of toner is equal to or less than the predetermined amount ("YES" in step S24), CPU 1 displays on display section 11 to supply toner (step S25).

In the above embodiment, step S25
Although the presence or absence of toner is displayed on the display unit 11, the detected remaining amount of toner may be displayed as a specific numerical value. Display to prepare the toner of
Further, a display requesting replacement may be performed when the amount of remaining toner is low.

When the developing device 91 itself does not exist, the amount of light received by the light receiving section 932 becomes larger irrespective of the remaining amount of toner inside the developing device 91 than when the developing device 91 exists. When the developing device 91 is not provided, the light receiving portion 932 is formed as the two concave portions 941 and 942 of the paddle 911 pass through the facing gap 940.
Does not occur. Therefore, when the developing device 91 is not mounted, it is needless to say that the CPU 1 can easily detect the fact. In such a case, the CPU 1 performs an appropriate display on the display unit 11. It is possible to call attention to the user.

Incidentally, a photoelectric sensor (photo interrupter)
The correspondence between the amount of received light and the output of the detection signal may be directly proportional or inversely proportional. It goes without saying that either type may be used. Further, the image forming apparatus of the present invention is applicable regardless of whether the toner is a magnetic toner or a non-magnetic toner.

In the above embodiment, the paddle 911
The rotation cycle of the paddle 911 is measured by a timer, but a rotary encoder is attached to the rotation shaft of the paddle 911, and the toner sensor 91
The CPU 1 may take in the 0 detection signal.

[0045]

As described in detail above, according to the image forming apparatus of the present invention, since the remaining amount of toner in the developing device can be specifically detected, not just the presence or absence, it is possible for the user to replace the toner. Is notified that the toner is approaching, it is possible to prepare a spare toner.

[Brief description of the drawings]

FIG. 1 is a functional block diagram of a facsimile apparatus showing one configuration example of an embodiment when an electrophotographic image forming apparatus according to the present invention is applied to a facsimile apparatus, and shows a configuration example of an image forming apparatus of the present invention. It is a schematic diagram.

FIG. 2 is a schematic diagram showing a toner sensor of the image forming apparatus of the present invention and a developing device in the vicinity of a portion where the toner sensor is mounted;

FIG. 3 is a flowchart showing a processing procedure of a CPU based on a detection result by a toner sensor of the image forming apparatus of the present invention.

FIG. 4 is a schematic diagram illustrating the contents of a lookup table referred to by the CPU when the CPU performs processing based on the detection result of the toner sensor of the image forming apparatus of the present invention.

FIG. 5 is a flowchart showing another example of the processing procedure of the CPU based on the detection result by the toner sensor of the image forming apparatus of the present invention.

FIG. 6 is a schematic diagram showing the contents of a lookup table referred to by the CPU in another example of the processing of the CPU based on the detection result by the toner sensor of the image forming apparatus of the present invention.

[Explanation of symbols]

1 CPU, 9 recording unit, 91 developing unit, 910 toner sensor, 911 paddle, 931 light emitting unit, 932 light receiving unit.

Claims (3)

[Claims] 1. An image forming apparatus having a stirring device for stirring toner in a developing device, wherein a photoelectric sensor capable of detecting a change in transmitted light amount accompanying stirring of the toner by the stirring device in the developing device; Calculating means for calculating a remaining amount of toner in the developing device based on a detection output of the photoelectric sensor. 2. The image forming apparatus according to claim 1, wherein the calculating unit is configured to calculate a remaining amount of toner in the developing device based on an average value of a predetermined number of past detection outputs of the photoelectric sensor. Image forming apparatus. 3. The method according to claim 1, wherein the calculating unit calculates the remaining amount of toner in the developing device based on a number of times equal to or less than a predetermined value in the past predetermined number of detection outputs of the photoelectric sensor. The image forming apparatus according to claim 1.