JP2000181214A - Toner residual amount detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure stable operation at a low cost and to obtain excellent detection performance by calculating the arithmetic value contrasting the travel detected by a toner replenishment operation detecting means and the image signal quantity detected by an image signal detecting means. SOLUTION: The toner replenishment operation detecting means 91 detects the operation of a toner replenishing device which replenishes a developing device with toners. The image signal detecting means 92 detects the presence or absence of the image signal. A toner residual amount detection control section 90 integrates the signals from the toner replenishment operation detecting means 91 and the image signal detecting means 92 respectively according to the toner residual amount detection program read out of a ROM 93 and contrasts the respective integrated values. Toner consumption is proportional to the integrated value of the image signals and the travel of the toner replenishing means is proportional to the toner consumption. Then, judgment is made that the amount of the toners in a toner bottle 30 is insufficient in case of a deviation from a straight line at which the relation between the integrated value of the image signal and the travel of the toner replenishing means is proportional. A warning signal is emitted to a warning display section 94.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic image forming apparatus, and more particularly to an apparatus for detecting a remaining amount of toner in a toner bottle for displaying a warning prompting toner replenishment.

[0002]

2. Description of the Related Art In an electrophotographic image forming apparatus, that is, an electrophotographic apparatus, toner is normally supplied so that toner consumed in image formation is supplied so that an image having a proper density is always formed. Equipment is equipped. Such a toner supply device requires a toner remaining amount detecting device for detecting the remaining amount of toner in the toner bottle. As a conventional toner remaining amount detecting device, there are a device that detects a toner remaining amount by using a piezo element, and a device that optically detects a toner remaining amount.

[0003]

However, the above-mentioned prior art has a disadvantage that the former is costly. In particular, in the case of a color image forming apparatus, the remaining amounts of toner in cyan, magenta, yellow, and black toner bottles are different. A detection device is required, which further increases the cost.

In addition, the optical toner remaining amount detecting means has a problem that not only the cost is increased but also reliability and stability are increased.

An object of the present invention is to provide a toner remaining amount detecting device which operates stably at low cost and has excellent detection performance.

[0006]

The object of the present invention is as follows.
An image forming apparatus for forming a digital image in which toner in a toner storage unit is supplied with toner to a developing device by an operation of a toner supply operation unit, wherein the toner storage unit is replaceable, and the toner is replaced in the first half of the replacement. A toner replenishing operation detecting means for replenishing a substantially predetermined amount of toner in accordance with the operation of the replenishing portion, and having a replenishing characteristic in which the toner replenishing amount gradually decreases in the latter half, and detecting the amount of operation of the toner replenishing portion. Image signal detecting means for detecting an image signal to be recorded; and calculating means for calculating a calculated value obtained by comparing the amount of operation detected by the toner supply operation detecting means with the amount of image signal detected by the image signal detecting means. When the calculated value reaches the predetermined value A, it is determined that the remaining amount of toner in the toner storage unit has reached the predetermined remaining value, and the calculated value is changed to the predetermined value B. Then is achieved the and determining residual amount judging means and that the toner has run out in the toner storage means, by the toner remaining amount detection apparatus characterized by having a (first invention).

In an image forming apparatus for supplying toner to a developing device by operating a toner replenishing operation section with toner in a replaceable toner storage section, the operation of the toner replenishment operation section after the replacement of the toner storage section is performed. The relationship between the toner supply and the toner supply has a unique supply characteristic. The toner supply operation detection means for detecting the operation amount of the toner supply operation unit, the operation amount and the toner supply amount detected by the toner supply operation detection means. An integrated value calculating means for calculating an integrated value of: and when the integrated value reaches a predetermined value A1, it is determined that the remaining amount of toner in the toner storage means has reached a predetermined remaining amount value, and the integrated value is determined to be a predetermined value. And a remaining amount determining unit that determines that the toner in the toner storing unit has run out when the value reaches the value B1.
Achieved by

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (1) Image Forming Apparatus Prior to description of an embodiment of the present invention, a color image forming apparatus equipped with a plurality of sets of toner replenishing devices and provided with a toner remaining amount detecting device of the present invention. The configuration and operation of a digital color printer as an example will be described with reference to the cross-sectional view of FIG.

In this color printer, a color image is formed by superimposing toner images of respective colors sequentially formed on an image forming body onto a recording material at a transfer section once, and fixing the recording material. This is a color image forming apparatus that forms a color image thereon.

In FIG. 1, reference numeral 10 denotes a photosensitive drum which is an image forming body, which is formed by applying an OPC photosensitive body (organic photosensitive body) on a drum base, is grounded, and is driven and rotated clockwise in the drawing. . Reference numeral 11 denotes a scorotron charger, which comprises a grid maintained at a constant potential and a corona discharge wire connected to a high-voltage power supply, and charges the surface of the photosensitive drum 10 to a uniform potential. Prior to the charging by the scorotron charger 11, in order to eliminate the history of the photoconductor, exposure is performed by a PCL (pre-charging static eliminator) 12 using a light emitting diode or the like to eliminate the charge on the peripheral surface of the photoconductor.

After the photosensitive drum 10 is uniformly charged, image exposure based on an image signal is performed by an image writing means 13 constituted by an image exposure device. The image writing means 13 includes a laser diode (not shown) and the rotating polygon mirror 1.
31, fθ lens 132, cylindrical lens 133
After that, scanning exposure is performed by the reflection mirror 134 after passing through. In the present embodiment, the image portion is exposed, and a latent image is formed such that the image portion has a lower potential than the non-image portion.

Around the photoreceptor drum 10, developing devices each containing a two-component developer composed of a toner such as yellow (Y), magenta (M), cyan (C) and black (K) and a carrier are used. Certain developing units 20Y, 20M, 20
A developing unit 20 composed of C and 20K is provided.

First, development with yellow toner of the first color is performed by a developing sleeve 21 which is a developer carrying member which contains a magnet and rotates while holding a developer. The developer consists of a carrier with ferrite as the core and an insulating resin coated around it, and a toner with polyester as the main material and a pigment according to the color, a charge control agent, silica, titanium oxide, etc. The agent is applied on the developing sleeve 21 to a thickness of 100 to 600 μm
And is conveyed to the developing area by the regulation of the developer layer thickness.

The gap between the developing sleeve 21 and the photosensitive drum 10 in the developing area is set to a value larger than the thickness of the developer layer, for example, 0.2 to 1.0 mm, and the DC bias and the AC bias are superimposed on this gap. The applied bias voltage is applied. As the DC bias, a bias voltage having the same polarity as that of the toner for developing the latent image is applied, and the toner adheres to a low potential portion of the latent image to perform development. That is, reversal development is performed.

After the visualization of the first color is completed, a magenta image forming process for the second color is started, and the scorotron charger 1 is again turned on.
1 is performed, and a latent image based on the image data of the second color is formed by the image writing unit 13. At this time, the charge removal by the PCL 12 performed in the image forming process for the first color is not performed. After the formation of the latent image, development with magenta toner is performed by the developing device 20M, and a magenta toner image is formed on the photosensitive drum 10.

The same image forming process as that for the second color magenta is performed for the third color cyan and the fourth color black, and a visual image of four colors of yellow, magenta, cyan and black is formed on the photosensitive drum 10. Is done.

Each of the developing units 20Y, 20M, 20C, 2
The toner replenishing device 40 for replenishing each color toner at 0K includes toner bottles 30Y, 30
Bottle mounting portions 41Y, 41M, 41C, and 41K for detachably mounting M, 30C, and 30K, respectively, and toner reservoirs 42Y, 42M, 42C, and 42K for temporarily storing the toner in the toner bottles 30Y, 30M, 30C, and 30K.
And the toner in the toner reservoirs 42Y, 42M, 42C, 42K is transferred to the developing units 20Y, 20M, 20C, 20K.
Conveying units 43Y, 43M, 43C, 43 for conveying to
K.

On the other hand, the half-moon roller 5
1 is temporarily stopped near the pair of registration rollers 54 via the pair of paper feed rollers 52 and 53, and is rotated by the rotation of the pair of registration rollers 54 when the transfer timing is adjusted. Paper is fed to the transfer area.

In the transfer area, a transfer means 60 is pressed against the peripheral surface of the photosensitive drum 10 in synchronization with the transfer timing, and the fed recording material p is sandwiched to transfer a multicolor image at a time. You.

Next, the recording material p is discharged by the separating means 61, separated from the peripheral surface of the photosensitive drum 10 and conveyed to the fixing device 70, where the heat roller (upper roller) 71 and the pressure roller (lower roller) 72 After the toner is fused by heating and pressurizing, the toner is discharged onto a discharge tray 83 outside the apparatus via discharge rollers 81 and 82. The transfer means 6
Numeral 0 is retracted from the peripheral surface of the photosensitive drum 10 after passing the recording material p to prepare for the formation of the next toner image.

On the other hand, the photosensitive drum 10 that has passed the transfer separation position is subjected to static elimination by the static eliminator 14, and then the residual toner is removed and pressed by the pressure contact of the blade 151 of the cleaning device 15 to be cleaned again. Upon receiving the charge by the scorotron charger 11, the process proceeds to the next image forming process. The blade 151 moves immediately after the cleaning of the surface of the photoconductor and moves away from the peripheral surface of the photoconductor drum 10. The waste toner scraped into the cleaning device 15 by the blade 151 is discharged by the screw 152 and then stored in a waste toner collecting container (not shown).

(2) Toner replenishing device FIG. 2 shows toner bottles 30Y, 30M, 30C and 30K.
And the toner pools 42Y, 42M, 42C, and 42K.
FIG. 5 is a perspective view illustrating a part of the developing devices 20Y, 20M, 20C, and 20K. Storage container mounting portions 41Y, 41M, 41C,
41K has four types of toner bottles 30Y and 30Y, respectively.
M, 30C and 30K are installed in parallel on substantially the same plane, and are detachable. The developing units 20Y, 20M, 20C, 2
When the amount of toner in 0K decreases, each toner in the toner bottles 30Y, 30M, 30C and 30K is replenished at a controlled rate. Since these toner bottles 30Y, 30M, 30C, and 30K have substantially the same configuration, hereinafter, these toner bottles 30Y, 30Y,
The toner bottle 30 will be described as a representative of the toner bottles 30M, 30C, and 30K.

As shown in FIG. 3, the toner bottle 30 has a cylindrical shape, and a spiral projection protruding from the inner peripheral surface of the cylindrical portion is formed at the cylindrical portion as shown at 31.
As will be described later, the protrusion 31
The toner T contained in the container bottom portion,
That is, the toner is moved from the upper right portion in FIG. 3 to the container opening, that is, the lower right portion. At the mouth of the toner bottle 30, a detachable solid lid 32 and an elastic
3 are provided.

FIG. 4 shows a state where the toner bottle 30 is mounted on the toner supply device. The toner bottle 30 is mounted by screwing a screw provided on the outer periphery of the solid lid 32 into the container receiving member 44 of the image forming apparatus main body. In this mounting state, the extendable lid 33 of the toner bottle 30 is attached to the wall 421 provided on the container receiving member 44 of the apparatus main body.
, And is compressed as shown in FIG.
An opening that allows the passage of toner is formed between the front end cover 327 and a part of the front end cover 327 that forms a part of the toner. As shown in FIG. 3, when the toner bottle 30 is not attached to the image forming apparatus, the extensible lid 33 is in close contact with the distal end lid 327 by its own elasticity, and the toner does not flow out of the toner bottle 30. Absent.

Next, the toner supply mechanism will be described.

The toner T in the toner bottle 30 moves from the right to the left along the bottom of the cylindrical portion of the toner bottle 30 by the rotation of the toner bottle 30 by the feeding action of the projection 31. At the mouth of the toner bottle 30, that is, at the right end, the toner T is supplied to the scraping member 3 provided on the solid lid 32.
21 and 322. The scraped toner T slides down on the conveying slopes 323 and 324, falls on the conveying screw 43, is conveyed by the conveying screw 43, and is developed from the opening 50 through the developing device (20Y, 20M, 20C).
Or 20K, hereinafter referred to as 20). That is, as shown in FIG. 5, the toner T is supplied from the toner bottle 30 → the scraping members 321 and 322 → the conveying slope 3
The developer is supplied to the developing device 20 through a route of 23, 324 → a conveying screw 43 → an opening 50.

In FIG. 4, reference numeral 45 denotes an encoder comprising a signal generating member 45a for measuring the number of rotations of the transport screw 43 and a sensor 45b. Since the transport screw 43 and the toner bottle 30 are driven by the same motor, the rotation speed is the same regardless of which rotation speed is to be detected. Therefore, the rotation of the transport screw 43 is detected by the encoder 45 and used as control.

The scraping action of the scraping members 321 and 322 will be described.

A member for scraping out the toner from the toner bottle 30 is provided on the solid lid 32.

FIG. 6 shows the solid lid 32 from which the telescopic lid 33 has been removed.
FIG. 3 is a front view of the device, showing scraping members 321 and 322 provided on a cylindrical lid base, conveying slopes 323 and 324, and a tip lid 3;
27.

As shown in FIG. 6, a scraping member 321,
322 has slopes inclined in opposite directions. FIG.
As shown in FIG. 6 and FIG. 9 in which the fixed lid 32 is rotated by 90 ° in the rotation direction indicated by A from FIG. 6, the conveying slopes 323 and 324 are moved with respect to the rotation direction A of the solid lid 32 with respect to the slopes of the scraping members 321 and 322. They are provided 90 ° out of phase. 6 and 9, the white arrow indicates the direction of inclination of the slope, and the direction of the arrow indicates the direction of falling in a direction perpendicular to the paper surface. The scraping members 321 and 322 and the conveying slope 323
Although not shown, an opening through which toner passes is formed between 324.

FIG. 7 is a right side view of the solid lid 32 shown in FIG. As shown in FIG. 7, the solid lid 32 has a scraping member 32 symmetrical about the rotation axis of the toner bottle 30.
1, 322 are provided, and these slopes are bisected slopes inclined in opposite directions as shown in FIG. 7 (FIG. 7).
Indicates the direction of inclination of the scraping member, and the direction of the arrow is the direction in which the inclination is downward. FIG.
As shown in FIG. 8 which is a cross-sectional view taken along the line A, the scraping member 321 has a toner holding space for holding the toner by a side wall 321a, an arcuate wing 321b extending in the circumferential direction, and a center wall 321d together with the slope. Form E1.
Similarly, the scraping member 322 has its own slope, side wall 3
The toner holding space E2 is formed by the 22a, the arcuate wings 322b, and the center wall 322d. When the toner bottle 30 rotates, the solid lid 32 rotates as shown by the arrow A, and the toner T is scooped up by the arcuate wings 322b and held in the toner holding space E2 as shown in FIG.

The operation of transporting the toner T scraped by the scraping members 321 and 322 to the transport screw 43 will be described.

FIG. 9 shows a state in which the solid lid 32 is moved from the state shown in FIG.
It shows a state where it is rotated by 0 °. As is clear from FIGS. 6 and 9, the conveying slope 32 is positioned with respect to the scraping members 321 and 322.
3,324 are provided with a phase difference of 90 °. The transport slopes 323 and 324 are inclined in opposite directions.

A receiving member 44 for receiving the solid lid 32 of the toner bottle 30 is rotatably provided on the main body of the image forming apparatus, and is fixed to a gear 47. The receiving member 4 is driven by driving the gear 47 by a motor (not shown).
4 and toner bottle 30 rotate as shown by arrow A,
The solid lid 32 rotates similarly.

By this rotation, the toner T, which is scooped up by the arcuate wings 321a of the scraping member 321 and held in the holding space E1, is rotated at a rotational position where the scraping member 321 is inclined downward to the left as shown in FIG. , Fall on the slope, and fall on the transport slope 323. Similarly, the toner T scraped out by the scraping member 322 transfers the toner T
4 fall on.

The conveying slope 323 is formed so as to have a 90 ° delayed phase with respect to the scraping member 321, as shown in FIG.
Receiving the toner T dropped from the transfer screw 21
3 to be transported. Similarly, the conveying slope 324 receives the toner T dropped from the scraping member 322 and conveys the toner T onto the conveying screw 43.

As described above, the movement path of the toner T from the toner bottle 30 to the transport screw 43 is shown in FIG.
Move as shown by arrow B in FIG.

The transport screw 43 is rotated by a gear 431 driven by a motor (not shown) together with the toner bottle 30 to transport the toner T from left to right in FIG. Convey to 50. The developing device 20 is provided with, for example, a toner concentration detection device that detects the toner concentration of the developer from the magnetic permeability of the developer. Based on a signal from the toner concentration detection device,
Toner bottle 30, solid lid 32 and transport screw 43
Rotates to supply toner. Scraping member 321
And the scraping member 322 is configured to have a difference in the scraping ability.

As shown in FIG. 8, the scraping member 321 has a tip 321e provided at the tip of the arc-shaped wing 321b. On the other hand, the tip of the arc-shaped wing 322b of the scraping member 322 has no tip wing. Scraping member 32
The distance between the inner peripheral surface of the solid lid 32 and the inner peripheral surface of the solid lid 32 is formed narrower by providing the tip wings 321 e. Therefore, the scraping member 321 can scoop up the toner until the remaining amount of toner in the toner bottle 30 becomes smaller than the scraping member 322. That is, the scraping member 321 and the scraping member 322 are configured to have a difference in the scraping ability.

With the structure of the scraping members 321 and 322, when the remaining amount of toner in the toner bottle 30 is reduced, the transport amount or the transport ratio is not sharply reduced but is gradually reduced.

(Embodiment 1) FIG. 10 shows the change of the toner supply amount with respect to the total screw rotation speed which is the integrated value of the rotation speed of the conveying screw 43 of the toner supply device 40 shown in FIG. In the figure, the total screw rotation speed is N ₀ (2
Until 00), the stable area indicates a substantially constant toner supply amount, but thereafter, the toner supply amount decreases. However, in the toner supply device shown in FIG. 4, when the remaining amount of toner in the toner bottle 30 becomes small, the toner supply amount or the toner supply ratio gradually decreases.

FIG. 11 is a block diagram showing a toner remaining amount detecting device used in the toner replenishing device shown in FIG. The toner replenishing operation detecting means 91 is an operation detecting means for detecting the operation of the toner replenishing device 40 for replenishing the developing device 20 with toner. When the developing device 20 is a developing device using a two-component developer, the toner replenishing operation is performed based on a signal that the toner concentration detecting device in the developing device detects that the developer concentration in the developing device 20 has decreased. I do. When the developing device 20 uses a one-component developer, a replenishing operation is performed based on a signal indicating that the amount of the developer in the developing device 20 is insufficient. In the present embodiment, toner is supplied by rotation of the toner bottle 30 and the transport screw 43. The operation detecting means detects the toner replenishing operation of the toner replenishing device 40, and in the present embodiment, the toner bottle 30 and the transport screw 4
3 is driven by the same motor, the toner supply operation amount can be detected by detecting the rotation speed of the transport screw 43. Specifically, a signal generating member 45a of an encoder is provided on a drive gear 431 of the transport screw 43, and rotation of the transport screw 43 is detected by a sensor 45b. The warning display unit 94 is provided in the operation unit of the apparatus main body, and indicates that a warning indicating that the remaining amount of toner in the toner bottle 30 has decreased, or that the remaining toner amount has decreased, or that it is time to replace the toner bottle 30. This is a warning display section for indicating that

An image forming apparatus to which the present invention is applied is an image recording apparatus which records an image in accordance with an image signal. The image signal is obtained by reading and processing an original image and an image signal obtained by an input operation. Image signal or an image signal generated from transmitted data.
An image signal detection unit 92 is an image signal reading unit that detects the presence or absence of an image signal, and is a circuit that generates an input signal to the toner remaining amount detection control unit 90 in accordance with the image signal to the recording unit of the image recording apparatus. is there. Specifically, a sampling circuit that samples an image signal to the recording unit with a clock having a constant frequency is used.

As described later, in the present embodiment, the amount of the image signal is integrated, but the image signal reading section may output a signal corresponding to a pulse carrying image data. When the image signal is a binary signal, a counter for counting the image signal may be used.

The toner remaining amount detection control section 90 accumulates each of the signals from the toner replenishing operation detecting means 91 and the image signal detecting means 92 according to a program read from the ROM 93 storing the toner remaining amount detecting program, There is a calculating means for comparing the integrated value.
Hereinafter, this integration and comparison will be described with reference to FIG.

According to the experiment of the present inventor, it is found that the consumption amount of the toner T is proportional to the number of print dots, and that the total screw rotation number of the operating portion of the toner supply device 40 has a fixed relationship with the total supply time. Was.

In FIG. 12, the horizontal axis represents the cumulative number of print dots, which is the integrated number of image signals, and the vertical axis represents the cumulative number of rotations of the toner bottle, which is the cumulative value of the operation amount of the toner supply device 40. The integrated value of the image signal is the amount of the image signal. The operation amount is specifically an integrated value of the number of rotations of the transport screw 43, and is hereinafter referred to as an integrated bottle rotation number. In the stable region shown in FIG. 10, the image signal amount and the operation amount of the toner replenishing unit have a proportional relationship, that is, a linear relationship. That is, the amount of toner consumption is proportional to the integrated value of the image signal, and the amount of operation of the toner replenishing means (integrated bottle rotation speed) is proportional to the amount of toner consumption. The straight line portion of the curve G in FIG. 12 shows such a proportional relationship. However, when the amount of toner in the toner bottle 30 decreases and the toner conveyance efficiency of the toner replenishing unit decreases, and the point e exceeds the stable region in FIG. 10, this proportional relationship is broken. As a result, as shown by R at the right end of the line G, the correspondence relationship is not a straight line but a curve (the accumulated bottle rotation speed at point e is N ₀ ).

The present embodiment focuses on such a relationship between the integrated value of the image signal and the operation amount of the toner replenishing means. When the relationship between the two deviates from a straight line, the toner storing means is used. By making a judgment system for judging that the amount of toner in a certain toner bottle 30 is insufficient, it is warned that the amount of toner in the toner bottle 30 has decreased, and a replacement of the toner bottle 30 is instructed to ensure toner supply. To be able to do it.

Next, according to the flowchart of FIG.
The operation of an example of the toner supply determination system will be described.

[0051] to accumulate the rotational speed of the conveying screws 43 is an operation amount of the toner replenishing means (bottle speed) in step S _1. This integration is an integration from the time when the toner in the toner bottle 30 is full, that is, when the toner bottle 30 is in the initial state after the replacement of the toner bottle 30 is performed. In Step S ₂ above cumulative bottle rotation speed N is determined whether or not reached N _0, N performs arithmetic processing α is the ratio of the integrated value of the up to now exceeds N ₀ (S _3). The calculation of α is a calculation for observing the ratio of the toner supply operation amount and the image signal amount (α = cumulative bottle rotation speed / cumulative print dot number) in a state where the remaining amount of toner in the toner bottle 30 is a sufficient amount. That is, the process up to step S ₃ is a process view slope of the linear portion of the line G in FIG. 12.

Next, in step S ₄ , for example, C is calculated every ten rotations of the toner bottle 30. Where C is C
= [(N + 10) -α × the cumulative number of dots], and calculates the amount of the cumulative bottle rotational speed N deviating from the linear portion. In Step S _4, N corresponding to the toner replenishing operation amount is initialized. If C is a predetermined value A from whether a large is judged C <A in step S _5,
The process proceeds to step S ₆ After a re 10 C is calculated for each rotation C> A, indicating that the remaining amount of toner is low in the warning display unit 94. The predetermined value A is, for example, 2
A value corresponding to 0% is selected. Step S
_{In step 7} , C is calculated again every 10 rotations of the toner bottle 30, and N is initialized. C in step S ₈
There whether exceeds a predetermined value B is determined, while the C <B is repeated again calculated in step S _7. When C> B, a toner replenishment signal (replacement request for the toner bottle) is output to the warning display section 94 (S ₉ ).

In response to the toner supply signal, the (warning means) of the toner supply warning display section 94 operates to warn the operator of toner supply. As a form of the toner supply warning,
A warning of toner replenishment is issued simply by one signal. When the remaining amount of toner reaches a predetermined amount a as described above, an initial warning is first issued to warn that the remaining amount of toner is low, and the next predetermined amount b
When the toner supply warning is reached, a warning is issued along with a toner supply warning, and a preliminary warning is issued with an initial warning. It is designed to give a toner replenishment warning suitable for the use of the image forming apparatus, such as one that prohibits printing.

If a stepping motor is used to drive the toner bottle 30 and the conveying screw 43, the driving pulse is measured and integrated, so that the integrated value of the operation amount of the toner replenishing means can be known by a simple configuration. it can.

The developing performance of the developing device is not always constant.
In particular, in the case of the two-component developing method, due to the fatigue of the developer,
The relationship between the toner density in the developer and the development density (image density) changes. Accordingly, in some cases, a desired image density can be obtained by increasing the operation amount of the toner replenishing means with respect to the image signal amount and increasing the toner density of the developer in the developing device. In such a case, the above ratio, α, will change. Therefore, in such a case, correction is performed in the step of performing integration or ratio calculation in FIG. With this correction, the remaining amount of toner in the toner storage unit is accurately measured.

Although not shown, when a new toner bottle 30 is mounted and new toner is supplied, a new toner supply signal is received and stored in the storage unit. The operating amount, the image signal amount, and the ratio (α) are canceled and initialized. Further, as a countermeasure when the relationship between the operation amount of the toner supply unit and the image signal amount indicates an abnormal value due to a failure of the apparatus, the control unit includes an abnormality detecting unit.

The toner remaining amount detecting device shown in FIG. 11 and described above detects that the remaining amount of toner has decreased due to a change in the toner supply rate. In the toner replenishing device provided with such a toner remaining amount detecting device, as shown by a curve L2 in FIG. 14, when the toner replenishing amount sharply decreases, a signal (toner replenishment signal) indicating that the toner remaining amount has decreased. Shortly after ()), toner replenishment becomes zero.

From a practical viewpoint such as ease of use, such an operation is not desirable. Toner supply is continued for a while even after the toner supply signal is output, and an image can be formed. desirable.

In the toner replenishment characteristic as shown by a curve L2 in FIG. 14, the remaining amount of toner at the time when the remaining toner amount detection device is activated varies, that is, the operation of the remaining toner amount detection device becomes unstable. By employing the toner supply device having the toner supply characteristics indicated by L1, the operation of the toner remaining amount detection device of the present embodiment is stabilized.

(Embodiment 2) FIG. 15 is a block diagram of another toner remaining amount detecting device according to claim 8 of the second invention. FIG. 15 is the same as the block diagram shown in FIG. 11 except for the image signal detecting means 92, and the reference numerals in FIG.
It is shown with a symbol.

As a result of experiments on a large number of toner replenishing devices 40, the relationship between the toner replenishment amount per second (g / s) and the replenishment time T (sec), which are the toner replenishment characteristics of the toner replenishment device 40 shown in FIG. As a result, a graph as shown in FIG. 16 was obtained.

The graph shown by the dotted line indicates that the replenishment time is from 0 to 20.
0 sec, 201-300 sec, 301-400 sec
c, the average of the toner supply amount in each section (0.
34g, 0.26g, 0.12g).

Therefore, the integrated replenishment amount m in each section is: m = 0.34 g × T in the section from 0 to 200 sec.
(0 <T <200) In the section from 201 to 300 sec, m = 0.34 g × 200 + 0.26 g × (T−200)
... (200 <T <300) In the section of 301 to 400 sec, m = 0.34 g × 200 + 0.26 g × (300−20)
0) +0.12 g × (T-300) (300 <T <4
00) can be used. Thus, an integrated supply amount m obtained from the supply time T is calculated. The replenishment time T is the operation time of the toner replenishing device 40, and uses the integrated value of the operation time obtained by the toner replenishment operation detecting means 91a.

The toner remaining amount detection control unit 90a calculates the integrated toner supply amount m, subtracts it from the total toner amount M in the new replacement toner bottle 30, and displays this in the warning display unit 94a as shown in FIG.
The remaining amount of toner is displayed by the bar graph shown in FIG. When the remaining amount of toner becomes equal to or less than the predetermined value A1, a warning that the remaining amount of toner is low is displayed, and when the remaining amount of toner reaches the predetermined value B1, a toner supply signal is output to the warning display unit 94a. In response to the toner replenishment signal, the (warning means) of the toner replenishment warning display unit 94a operates to warn the operator of toner replenishment (replacement of the toner bottle). Regarding this warning display, the same method as that described in the first embodiment is performed.

In any of the above-described embodiments, the toner replenishment amount by the transport screw 43 is transported so that the volume of the transported toner is constant, so that the weight g transported according to the “bulk density” of the toner is reduced. Change. Since the "bulk density" may vary by several percent due to the variation in toner production conditions, the weight g of the toner filled in the toner bottle 30 is changed to correct the variation. Specifically, if the “bulk density” increases by 1%, the filling amount is reduced by 1%
The remaining amount control is corrected with a measure of increasing the remaining amount.

The "bulk density" is measured by dropping the toner from above into a cylindrical cylinder at a fixed rate (0.5 g / sec or the like) and filling the toner with the toner for a fixed time (60 sec.).
Etc.) The “bulk density” of the toner in the cylinder in a statically stable state after being allowed to stand was measured.

If the toner supply from the toner bottle 30 decreases sharply, the detection performance becomes unstable. Therefore, as described above, the scraping members 321 and 322 of the toner bottle 30 change the toner conveyance amount. Preferably, it does not occur suddenly.

Although the embodiment of the present invention has been described above, the present invention is not limited to this embodiment, and various modifications are possible. For example, a screw that scrapes and conveys toner by rotation as a scraping means can be used, and the toner storage means can be provided in the main body of the image forming apparatus instead of a toner bottle.

[0069]

As described above, according to the detection method of the present invention, it is advantageous in terms of cost as compared with a piezo element or optical detection, and operates stably without fear of contamination on the sensor. Thus, it is possible to provide a toner remaining amount detecting device having excellent detection performance.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an example of an image forming apparatus in which a toner remaining amount detecting device according to the present invention is used.

FIG. 2 is a diagram illustrating a developing device and a toner replenishing device of the image forming apparatus illustrated in FIG. 1;

FIG. 3 is a perspective view of a toner bottle used in the image forming apparatus shown in FIG.

FIG. 4 is a front view (partially showing a cross section) of the toner supply device of the image forming apparatus shown in FIG. 1;

FIG. 5 is a diagram illustrating a movement path of toner in the toner supply device illustrated in FIG. 4;

6 is a front view of a solid lid of the toner bottle of the toner supply device shown in FIG.

FIG. 7 is a right side view of the solid cover shown in FIG. 6;

FIG. 8 is a cross-sectional view taken along the line II in FIG.

FIG. 9 is a view showing a state where the solid lid shown in FIG. 6 is rotated by 90 ° from FIG. 6;

FIG. 10 is a diagram illustrating a change over time of a toner supply amount of the toner supply device.

FIG. 11 is a block diagram of a toner remaining amount detecting device according to the first invention.

12 is a graph illustrating the detection of the remaining amount of toner by the remaining toner amount detection device of FIG. 11;

FIG. 13 is a flowchart of toner remaining amount detection according to the first invention.

FIG. 14 is a graph showing two types of supply characteristics of the toner supply device.

FIG. 15 is a block diagram of a toner remaining amount detecting device according to a second invention.

FIG. 16 is a graph showing a toner supply characteristic of the toner supply device of the second invention.

FIG. 17 is a graph showing a remaining toner amount display of the toner supply device of the second invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 photoconductor drum 11 charging device 13 image writing means 20 developing device (developing device) 30 toner bottle (toner storage device) 40 toner replenishing device 42 hopper (toner reservoir) 43 transport screw (toner transport portion) 45 encoder 90, 90a toner Remaining amount detection control section 91, 91a Toner replenishing operation detecting means 92 Image signal detecting means 93, 93a ROM 94, 94a Warning display section p Recording material T Toner

Claims (14)

[Claims] An image forming apparatus for forming a digital image in which toner in a toner storage unit is replenished with toner by operation of a toner replenishment operation unit, wherein the toner storage unit is replaceable. In the latter half, the toner replenishment unit has a replenishment characteristic in which a substantially predetermined amount of toner is replenished in accordance with the operation of the toner replenishment unit. Toner supply operation detection means, image signal detection means for detecting an image signal to be recorded, and an operation value obtained by comparing the operation amount detected by the toner supply operation detection means with the image signal amount detected by the image signal detection means Calculating means that calculates the remaining amount of toner in the toner storage means when the calculated value reaches a predetermined value A; Values remaining toner amount detecting apparatus characterized by having a residual amount judging means determines that the toner has run out in the toner storage means reaches a predetermined value B. A display unit for displaying a remaining toner level when it is determined that the calculated value has reached a predetermined value A and the remaining amount of toner in the toner storage unit has reached the predetermined remaining value. The toner remaining amount detecting device according to claim 1, wherein: 3. A display means for displaying that the remaining amount of toner has decreased when it is determined that the calculated value has reached a predetermined value A and the remaining amount of toner in the toner storage means has reached the predetermined remaining value. 2. The toner remaining amount detecting device according to claim 1, comprising: 4. When it is determined that the calculated value has reached a predetermined value B and the toner in the toner storage means has run out,
The toner remaining amount detecting device according to any one of claims 1 to 3, further comprising a display unit for displaying that the toner storage unit is to be replaced. 5. The toner according to claim 1, wherein said toner supply operation detecting means includes an encoder in said toner supply operation section, and detects an operation amount based on a rotation speed thereof. Remaining amount detection device. 6. The toner remaining amount detecting device according to claim 1, wherein said toner replenishing operation detecting means uses a control signal of an operation amount controlling means of said toner replenishing operating portion. apparatus. 7. The toner remaining amount detecting device according to claim 1, wherein the operation detecting unit detects an operation amount based on an operation speed and an operation time of the toner supply operation unit. . 8. An image forming apparatus for replenishing toner in a developing device with toner in a toner storage unit which is replaceable by operating a toner replenishment operation unit, wherein the operation of the toner replenishment operation unit after replacement of the toner storage unit is performed. The relationship between the toner supply and the toner supply has a unique supply characteristic. The toner supply operation detection means for detecting the operation amount of the toner supply operation unit; the operation amount and the toner supply amount detected by the toner supply operation detection means. Integrated value calculating means for calculating an integrated value of the following: when the integrated value reaches a predetermined value A1, it is determined that the remaining amount of toner in the toner storage means has reached a predetermined remaining value, and the integrated value is determined to be a predetermined value. And a remaining amount determining unit that determines that the toner in the toner storing unit has run out when the value reaches the value B1. 9. The toner remaining amount detecting device according to claim 8, further comprising display means for displaying at least one or more toner remaining amount levels according to the value corresponding to the integrated value. 10. A display means for displaying that the remaining amount of toner has decreased when it is determined that the integrated value has reached a predetermined value A1 and the remaining amount of toner in the toner storage means has reached the predetermined remaining value. The toner remaining amount detecting device according to claim 8, further comprising: 11. When the integrated value reaches a predetermined value B1 and it is determined that the toner in the toner storage unit is depleted, a display unit is provided for displaying replacement of the toner storage unit. The toner remaining amount detecting device according to claim 8. 12. The toner remaining amount detecting device according to claim 8, wherein said toner replenishment operation detecting means detects an operation amount based on a rotation speed of said toner replenishment operation part. 13. The toner remaining amount detecting unit according to claim 8, wherein said toner replenishing operation detecting unit uses a control signal of an operation amount controlling unit of said toner replenishing operating unit. apparatus. 14. The toner remaining amount according to claim 8, wherein said toner supply operation detecting means detects an operation amount based on an operation speed and an operation time of said toner supply operation section. Detection device.