JPS62105172A - Image forming device - Google Patents

Abstract

PURPOSE:To obtain an image forming device which does not cause erroneous detection of the remaining quantity of toner, by detecting the remaining quantity of the toner, generating signal data in accordance with it, and controlling the write of the signal data on a storage means and the readout of the signal data. CONSTITUTION:A toner quantity detecting means is constituted of a magnetic sensor 47 which has been installed to a casing in a state that a detecting head 47a has been exposed into a developing device. As a toner mixing ratio becomes large, an output voltage of the magnetic sensor 37 becomes small, and voltages Va-Vc are set as comparison voltages of a voltage comparator 50, and compared with the output voltage of the magnetic sensor 47. Also according as the output voltage of the magnetic sensor 47 varies, a toner replenishing signal S1, a toner quantity decreasing signal S2, and a toner empty signal S3 are varied. A microprocessor 55 checks the toner replenishing signal S1, the toner quantity decreasing signal S2, and the toner empty signal S3, in the timing which has been determined optionally, in a cycle, and simultaneously, writes a state of the signal of this time on a nonvolatile memory 51.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an image forming apparatus such as a copying machine having a remaining amount of toner detecting means.

[Technical background of the invention and its problems] Conventionally, in a copying machine, an actuator provided inside the toner hopper detects when the toner in the toner hopper runs out and indicates that the toner is out. Accordingly, a toner hopper is approached to a reed switch provided on the side surface of the toner hopper, and a magnet attached to the tip of an actuator turns on the reed switch to display an out-of-toner display.

However, with this type of toner remaining amount detection means, the reed switch is turned on before the toner in the toner hopper is completely exhausted.
This not only makes it impossible to accurately detect the amount of toner remaining in the toner hopper, but also makes it difficult to simplify the shape of the toner hopper when converting it into a cartridge, leading to increased costs. was there.

For this reason, a copying machine has been proposed in which a toner mixture ratio detection device detects the toner mixture ratio in the developer device and displays an out-of-toner message when the toner mixture ratio in the developer device falls below a predetermined value.

However, even in this copying machine, when the power is turned on again, the toner near the toner mixture ratio detection device is not rectified. There has been a problem in that no toner detection is performed even though the toner has run out.

[Object of the Invention] The present invention has been made in response to the above-mentioned circumstances, and an object of the present invention is to provide an image forming apparatus that does not erroneously detect the remaining amount of toner.

[Summary of the Invention] In order to achieve the above object, the present invention provides an image forming apparatus that includes a remaining toner amount detection means for detecting the remaining amount of toner, and a remaining toner amount detected by the remaining toner amount detection means. The apparatus is provided with a signal generation means for generating signal data using a non-volatile storage means, and a control means for controlling writing of the signal data into the storage means and reading of the signal data from the storage means. be.

[Embodiments of the Invention] Examples of the present invention will be described below with reference to the drawings.

FIG. 5 is a sectional view of one embodiment of the present invention.

That is, this image forming apparatus includes a main body 1 and a main body 1.
The document feeder 3 is provided so as to be openable and closable so as to cover the document table 2 on the upper surface of the document feeder 3. A paper feed cassette 4.5.6 is located on the right side of the main body 1, and a paper output tray 7 is located on the left side.
are installed respectively. The cassette cover of the paper feed cassette 4 at the top of the cassettes serves as a manual paper feed table 8 for manually feeding paper as appropriate.

Further, a photosensitive drum 9 is disposed approximately at the center of the main body 1 . Around this photosensitive drum 9, a charging device 10, an exposure optical system 11, a two-color color developing device 12,
Transfer charger 13, peeling charger 14, cleaning device 15,
, a power storage lamp 16, etc. are sequentially arranged.

Furthermore, a paper feed cassette 4.5.6 is provided at the bottom of the main body 1.
A paper feed roller 17 and a separation roller 1 for preventing double sheet taking.
8, or the paper manually fed from the manual paper feed tray 8, passes through the image transfer section 19 between the photosensitive drum 1 and the transfer charger 13, and then is transferred to the paper output tray. A paper conveyance path 20 leading to the paper sheet 7 is formed. and,
An aligning roller 21 is disposed on the upstream side of the image transfer section 19 of the paper conveyance path 20, and a heat roller 22 and a paper discharge roller 23 as a fixing device are disposed on the downstream side.

The developing device 12 is divided into a first developing device 121 and a second developing device 122, and the first developing device 121 uses a red (or yellow, blue, green, etc.) developer that is rarely used. , the second developing device 122 uses black developer, which is frequently used. Note that the above developer is a non-component developer consisting of toner and carrier. By selectively driving the first developing device 121 and the second developing device 122, color development of black or one color other than black (for example, red) is performed.

Roughly, the exposure optical system 11 includes an exposure lamp 24 that moves back and forth along the lower surface of the document table 2 in the direction of the arrow shown in the drawing, and irradiates light onto the document, and a first mirror that reflects light reflected from the document in a predetermined direction. 25, a second mirror 27 and a second mirror 27 that move in the same direction at half the speed in synchronization with the exposure lamp 24 and the first mirror 25 and reflect the reflected light from the first mirror 25 toward the lens unit 26 side. 3 mirror 28, and a fixed fourth mirror 296 and fifth mirror 30 that reflect the reflected light that has passed through the lens unit 26 in a predetermined direction.
It also includes a fixed sixth mirror 31 that reflects the reflected light from the fifth mirror 30 toward the photosensitive drum 9 side.

Next, the image forming operation of this image forming apparatus will be explained.

First, the exposure lamp 24 and the first mirror 25 are
The upper original is optically scanned and an image is formed on the rotating photoreceptor drum 9, and an electrostatic latent corresponding to the image of the original is formed on the photoreceptor drum 9, which is uniformly charged by the charging device 10. form an image.

The electrostatic latent image thus formed is opposed to the developing device 12, where it is developed into a developer image and sent to one image transfer section, where it is developed onto the paper fed by the aligning roller 21. The instrument image is transferred.

After the paper to which this developer image has been transferred is separated from the photosensitive drum 9 by the separation charger 14, the paper is transferred to the paper transport path 20.
The sheet is guided through the heat roller 22, where the transferred image is fixed, and then discharged to the paper discharge tray 7 by the paper discharge roller 23.

On the other hand, the photosensitive drum 9 after the developer image has been transferred onto the paper
The remaining developer (toner) is cleaned from the surface by facing the cleaning device 15, and the afterimage is roughly erased by the static elimination lamp 16, in preparation for the next copying operation.

FIG. 4 shows, for example, the second developing device 122 in detail, and is equipped with a magnetic sensor for detecting the toner mixing ratio. That is, this developing device 122 includes a developer conveying means A that conveys the developer from the toner hopper to the photoreceptor drum 9, a developer output means B, and a developer that adjusts the flow of the developer near the toner amount detecting means. It is composed of a rectifying means C, and a casing D that houses part of the developer conveying means A, the developer rectifying means C, and the toner amount detecting means B.

This developing device conveying means A includes a magnetic roller (developing roller) 41 that conveys the developer to a developing area, that is, a sliding contact area with the photoreceptor drum 9 by forming a magnetic brush for the developer on its surface, and a toner roller. A toner transport bag @ 44 consisting of a transport pipe 42 and a toner transport shaft 43 rotating within the toner transport pipe 42, and a first developer stirring unit that preliminarily mixes the toner transported by the toner transport device 44 with the developer. body 45 and
The second developer stirring body 46 stirs the developer.

Further, the toner amount detection means B is constituted by a magnetic sensor 47 attached to the casing D with the detection head 47a exposed inside the developing device.

Further, the developing device rectifying means C includes a doctor 48 that regulates the thickness of the magnetic brush on the magnetic roller 41, and a doctor 48 that regulates the thickness of the magnetic brush on the magnetic roller 41.
8 receives the developer scraped off by the magnetic sensor 47, and creates a stable flow of the developer toward the detection head 47a of the magnetic sensor 47.

FIG. 1 schematically shows the remaining amount detection means (1 to 4) in the image forming apparatus of the present invention.

That is, a magnetic sensor 47 whose detection head 47a is exposed inside the developing device, a voltage comparator 50 that compares the voltage output from the magnetic sensor 47 with a specified value and outputs the result as a signal, and a voltage comparator 50 that compares the voltage output from the magnetic sensor 47 with a specified value and outputs the result as a signal. The microprocessor 55 writes and reads data into a nonvolatile memory 51 and controls a toner replenishment motor 52, a toner amount decrease indicator 53, and a toner empty indicator 54.

Furthermore, the magnetic sensor 47 comes into contact with the developer in the developing container,
A detection head 47a that detects the magnetic permeability of the developer, an amplifier 47b that amplifies the minute output signal from the detection head 47a, an oscillator 47G that drives the detection head 47a and outputs a reference phase signal, and this oscillator 47A. a phase comparator 47d that compares the phase difference between the reference phase signal output from the amplifier 47G and the detection signal amplified by the amplifier 47b;
It is composed of a low-pass filter 47e that shapes the waveform of the signal output from the phase comparator 47d.

The characteristics of the output voltage of the magnetic sensor 47 with respect to the developer/toner mixture ratio are as shown in FIG. 2, and as the toner mixture ratio increases, the output voltage of the magnetic sensor 47 decreases. Here, the output voltage of the magnetic sensor 47 for the optimum toner mixing ratio Tc for obtaining a high-quality image is Vc, which is the toner mixing ratio when the toner in the toner hopper decreases and the amount of toner conveyed into the developing device decreases. The output voltage of the magnetic sensor 47 with respect to the ratio Tb is vb, and the output voltage of the magnetic sensor 47 with respect to the toner a sum ratio Ta when the toner in the toner hopper is exhausted and no toner is conveyed into the developing device is Va. . These Va, Vb, and Vc are set as comparison voltages of the voltage comparator 50 and compared with the output voltage of the magnetic sensor 47.

When the output voltage of the magnetic sensor 47 becomes higher than the specified value Vc, the voltage comparator 50 outputs the toner replenishment signal S1. When the microprocessor 55 receives this signal 81, it turns on the toner replenishing motor 52 of the toner replenishing means, thereby replenishing toner from the toner hopper.

Furthermore, when the output voltage of the magnetic sensor 47 becomes higher than the specified value vb, the voltage comparator 50 outputs a toner amount decrease signal S2. When the microprocessor 55 receives this signal S2, it lights up the low toner indicator 47, thereby warning the user that the amount of toner in the toner hopper has decreased.

Further, when the output voltage of the magnetic sensor 47 becomes higher than the specified value Va, the voltage comparator 50 outputs the toner empty signal S3. When the microprocessor 55 receives this signal S3, it lights up the toner empty indicator 54, thereby warning the user that the toner in the toner hopper is empty.

FIG. 3 shows changes in the toner replenishment signal S1, toner amount decrease signal S2, and toner empty signal S3 due to changes in the state inside the toner hopper and the output voltage of the magnetic sensor 47 when image formation is actually performed. be.

First, image formation is performed, the toner mixing ratio of the developer decreases, and the output voltage of the magnetic sensor 47 increases. And A
At this point, the toner mixing ratio of the developer falls below the specified level Tc, and the output voltage of the magnetic sensor 47 reaches the specified level ft1I.
When the voltage becomes higher than Vc, a toner replenishment signal S1 is output, and the toner replenishment motor 52 is turned on to replenish the developing device 121 with toner. In this way, feedback is performed so that the toner mixing ratio of the developer returns to the specified level TC.

Next, when the toner mixing ratio of the developer becomes higher than the specified level Tc, the output voltage of the magnetic sensor 47 becomes higher than the specified value Vc, the toner replenishment signal S1 becomes 0FFL, and toner replenishment is stopped.

In this way, when there is toner in the toner hopper and the toner is being replenished normally, the toner replenishment signal S1 is turned ON and OFF repeatedly, and the toner mixture ratio of the developer is controlled so as to converge to the specified level Tc. be done.

As the toner in the toner hopper gradually becomes consumed, the developer becomes an image, and the amount of consumed toner becomes unbalanced with the toner i supplied to the developer from within the toner hopper. In other words, when the toner in the toner hopper decreases, even though toner is being replenished,
The toner mixing ratio of the developer decreases. At this time, the output voltage of the magnetic sensor 47 gradually increases.

Then, at point B, when the toner mixing ratio of the developer falls below the specified level Tb and the output voltage of the magnetic sensor 47 becomes higher than the specified value vb, a toner I decrease signal S2 is output, and a toner amount decrease indicator is displayed. 53 lights up to warn the user that the toner i in the toner hopper is decreasing. Here, the specified value vb is specified at a value higher than the voltage value at which the output voltage of the magnetic sensor 47 overshoots when there is toner in the toner hopper and toner supply is balanced. .

When the toner in the toner hopper is further consumed and there is no toner, the toner mixing ratio of the developer decreases roughly, and the output voltage of the magnetic sensor 47 increases.

Then, at point 0, when the toner mixing ratio of the developer falls below the specified level Ta and the output voltage of the magnetic sensor 47 becomes higher than the specified value Va, the toner empty signal S3
is output, the toner empty indicator 54 lights up to warn the user that the toner in the toner hopper is empty, and the copying operation of the copying machine is stopped. Here, the specified value Va is defined by the output voltage of the magnetic sensor 47 at the lowest toner mixing ratio at which the developer does not adhere to the paper due to a decrease in the toner mixing ratio of the developer.

In such a toner remaining amount detection means, the magnetic sensor 47 detects the magnetic permeability when the developer in the developing device 12 is flowing, so when the developing device 12 is stopped,
The output voltage of the magnetic sensor 47 takes on an arbitrary value depending on the state of the developer near the detection head 47a.

Therefore, in this embodiment, the microprocessor 55 receives the toner replenishment signal S at an arbitrarily determined timing during the cycle in which the image forming apparatus forms an image on one sheet of paper.
1. At the same time as checking the toner amount decrease signal S2 and the toner empty signal S3, the signal status at this time is written in the nonvolatile memory 51.

FIG. 6 is a flowchart for explaining this operation.

First, when image formation is started, the developing device 12 is driven (
601, 602>, it is checked whether the toner replenishment signal S1 is ON after a certain delay time T1 (603, 604
).

When this toner replenishment signal S1 is ON, the data of this toner replenishment signal S1 is written into the nonvolatile memory 51 (605), and it is roughly checked whether the toner amount decrease signal S2 is ○ or not (606). ).

When this toner amount decrease signal S2 is ON, the data of toner amount decrease reception @$2 is written to the nonvolatile memory 51 (607), and it is roughly checked whether the toner empty signal S3 is ON ( 608).

When the toner empty signal S3 is ON, the data of the toner empty signal S3 is written to the nonvolatile memory 51 (609), and the image forming operation is stopped (61).
0).

Further, when the toner replenishment signal S1 is ON, the toner replenishment motor 52 is stopped (611), and the toner amount decrease signal S1 is stopped.
2 or when the toner empty signal S3 is OFF, the toner replenishment motor 52 is driven (612).

When forming images continuously, the above steps are repeated as one cycle 613), and after all image formation is completed, the toner replenishing motor 52 and the developing device 12 are stopped (614, 615) and the system enters a standby state. (616).

Next, the operation of this image forming apparatus when the power is turned on again will be explained.

In FIG. 7, when the power is turned on (701), data is first read from the nonvolatile memory 51 (702).
), it is checked whether the toner empty signal S3 is ON (703). This toner empty signal S3 is ON
In this case, the developing device 12 and the toner replenishment motor 52 are driven (704, 705), and toner empty processing is roughly executed (706).

Furthermore, if the toner empty signal S3 is OFF, it is checked whether the toner amount decrease signal S2 is ON (707);
When the toner amount reduction signal is ON, the developing device 12 and the toner replenishment motor 52 are driven (708, 709), and a toner amount reduction process is roughly executed (710).

Further, when the toner amount decrease signal S2 is OFF, it is checked whether the toner replenishment signal S1 is ON (711), and when the toner replenishment signal S1 is ON, the developing device 12 and the toner replenishment motor 52 are driven (712). , 713), and toner replenishment processing is further executed (714).

Note that when the toner replenishment signal S1 is OFF, it enters a standby state (715).

FIG. 8 is a flowchart showing toner empty processing.

In this toner empty processing, after turning on the toner empty indicator 53 (801), a check is repeated to see if the toner empty signal S3 has been turned off until a certain period of time T2 has elapsed since the power was turned on (802.80).
3) If a certain period of time T2 elapses without the toner empty signal $3 reaching 0FFL, the toner replenishment motor 52
Then, the developing device 12 is stopped (804 and 805), and the image forming operation is stopped (806).

Further, when the toner empty signal S3 is turned off, the toner empty indicator 53h is turned off (8
07), toner reduction processing is executed (808).

FIG. 9 is a flowchart showing the toner @ reduction process.

In this toner amount reduction process, first, the toner amount reduction indicator 53 is turned on (901), and a check is made to see if the toner amount reduction signal S2 is turned off for a certain period of time T from when the power is turned on.
Repeat until 2 elapses (902, 903). If the toner amount decrease signal S2 is not 0FFL during this time,
Stop the toner supply motor 52 and the developing device 904
．． 905), and the toner becomes depleted (906).

If the toner amount decrease signal S2 is turned off during this period, the toner amount decrease indicator 53 is turned off and (90
7) Execute toner replenishment processing (908).

FIG. 10 is a flowchart showing toner replenishment processing.

In this toner replenishment process, it is checked whether the toner replenishment signal S1 has been turned off until a predetermined time T2 has elapsed since the power was turned on (1001 and 1002). When the toner replenishment signal S1 is turned off or a predetermined time T2 has elapsed since the power was turned on, the toner replenishment motor 52 and the developing device are stopped (1003, 1004) and enter a standby state (1005).

In the above description, the case where the signal data stored in the non-volatile memory 51 is read out when the power is turned on has been explained, but the signal data stored in the non-volatile memory 51 can be read out when the toner hopper is replenished with toner. It is also carried out at different times.

[Effects of the Invention] As explained above, according to the present invention, since a signal corresponding to the remaining amount of toner is stored in a nonvolatile storage means, the remaining amount of toner can be detected correctly even when the power is turned on. .

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 is a block diagram schematically showing a remaining toner amount detecting device according to an embodiment of the present invention, FIG. The figure is a timing chart for explaining the toner replenishment operation, FIG. 4 is a vertical sectional view of the developing device of the same embodiment, FIG. 5 is a vertical sectional view of the same embodiment, and FIG. 6 is a micro FIGS. 7 to 10 are flowcharts for explaining the operation of the processor during image formation, and FIGS. 7 to 10 are flowcharts for explaining the operation of the microprocessor in the same embodiment when the power is turned on. 47...Magnetic sensor 50...Voltage comparator 51...Nonvolatile memory 55...
...Microprocessor agent Patent attorney Sasa Suyama - %1 Figure 2 Figure 10

Claims (3)

[Claims] (1) a remaining toner amount detection means for detecting the remaining amount of toner, a signal generation means for generating signal data in response to the remaining amount of toner detected by the remaining toner amount detection means, and a nonvolatile storage means; An image forming apparatus comprising: a control means for controlling writing of the signal data into the storage means and reading of the signal data from the storage means. (2) The image forming apparatus according to claim 1, wherein the control means reads signal data from the storage means when the power is turned on. (3) The image forming apparatus according to claim 1 or 2, wherein the signal generating means generates independent signals when toner runs out and when toner needs to be replenished.