JPH11102111A - Residual developer detector for image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect a residual developer in a developer housing part with high accuracy. SOLUTION: When a stirring paddle is operated (S1), the sampling of the output signal of a residual developer detecting sensor is executed at intervals of 10 ms by a fixed number of times (A times). During this period, the number of the results of the sampling (Y) as 'the absence of toner (developer)' is stored (S2-S6). When the sampling is executed by the fixed number of times (A times), Y/X is calculated from the number of sampling times (X) and the number of the results of the sampling (Y) as 'the absence of the toner (developer)' and compared with a prescribed value B (toner absence decision threshold) (S7). When Y/X > the prescribed value B is obtained, the absence of the toner is judged to execute processing for a waning display, etc. (S8).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for detecting the amount of a developer in an image forming apparatus, and more particularly, to a container for storing a developer to be supplied to a developing device in the image forming apparatus. The present invention also relates to a device capable of detecting the amount of developer in a storage container (including a collection container to be stored) with high accuracy.

[0002]

2. Description of the Related Art Conventionally, a developer (toner, carrier,
Since a satisfactory image formation cannot be performed if the developer (including the developer) is insufficient, a developer remaining amount detecting unit that detects the amount of the developer in the developer container (hereinafter, also referred to as a remaining amount) is provided. Accordingly, when it is detected that the remaining amount of the developer is insufficient, a warning of the insufficient remaining amount is displayed to urge the user to stop the image forming operation, to prompt the developer to be replenished, or to automatically replenish the developer. 2. Description of the Related Art An image forming apparatus configured to perform the operation is known.

In order to improve the detection accuracy of the developer remaining amount detecting means, for example, a detection time is taken for a predetermined time, and when the detection of the presence (or absence) of the developer is continued during the detection time, the true state is determined. In addition, there is also known one that determines that there is a developer (or no developer).

[0004]

However, for example, there is provided a means for stirring the developer in the developer container through a paddle (stirring member) or the like in order to prevent the developer from being fixed in the developer container. When equipped (see Fig. 4)
Also, when a cleaning member (cleaning means) for cleaning the detecting portion of the developer remaining amount detecting sensor is provided, the developer flows in the developer accommodating portion when such a device is operated, and the developer flows. Developer remaining amount detecting means (for example, turning on / off a micro switch in accordance with the remaining weight of developer, detecting the remaining amount of developer electrically using the dielectric constant of developer even though there is developer) Or a detector that detects the remaining amount of the developer based on the vibration characteristics of the piezo element that changes according to the amount of the developer in contact with the developer). There is a risk that the developer may be erroneously detected as missing, and that the remaining amount of the developer may not be detected accurately.

For example, in the case of detecting the remaining amount of the developer by an optical sensor including a light emitting element A and a light receiving element B as shown in FIG. 4, a rotary paddle (or a light emitting element and a light receiving element surface for stirring) is used. Due to the operation of the cleaning member for cleaning, etc., even though the developer is present, the gap between the light emitting element and the light receiving element is momentarily sparse, and there is a fear that the developer may be erroneously detected as not having the developer or disturbance (for example, image exposure or There is a risk that the developer is erroneously detected as no developer due to the invasion of sunlight or the like). Further, a cleaning member (or a rotating paddle for stirring) for cleaning the light emitting element and the light receiving element surface is not provided. By blocking between the light emitting element and the light receiving element, there is a possibility that the presence of the developer is erroneously detected even though the developer is not present.

That is, in the conventional configuration in which the remaining amount of the developer is detected based only on the output signal of the detection section (sensor) of the remaining amount of the developer, there is a high possibility of erroneous detection. It is. The same applies to the case where it is detected whether or not the waste developer is full in the collection container for collecting the developer that is unnecessary and discarded in the developing unit in the image forming apparatus. There is fear.

The present invention has been made in view of such a conventional situation, and has a simple and low-cost structure.
An object of the present invention is to provide a developer abundance detection device of an image forming apparatus which can detect the abundance of a developer in a developer accommodating section with high accuracy.

[0008]

According to a first aspect of the present invention, there is provided an apparatus for detecting the amount of a developer in an image forming apparatus according to the present invention.
As shown in the figure, while including a developer accommodating portion for accommodating a developer, a developer abundance detection sensor for detecting the abundance of the developer in the developer accommodating portion, at a predetermined period,
Sampling means for sampling the detection result of the developer abundance detection sensor, sampling a predetermined number of times by the sampling means, and the number of times of sampling, the detection result of the developer abundance detection sensor during the sampling a predetermined number of times is the same And a developer abundance detecting means for detecting the abundance of the developer in the developer accommodating section based on the number of times of occurrence.

With such a configuration, even if the developer abundance detection sensor may erroneously detect for a moment due to some influence (for example, the operation or disturbance of the stirring member or the cleaning member), Without immediately employing such an erroneous detection, the detection result of the developer abundance detection sensor is sampled a predetermined number of times at a predetermined cycle, and based on how many times the sampling result is the same, the developer storage is performed. Since the amount of developer present in the unit is detected, erroneous detection of the developer amount detection sensor can be eliminated as much as possible,
Thus, the accuracy of detecting the amount of the developer can be significantly improved, and the reliability of a warning display and the like can be improved.

More specifically, for example, during the operation of the stirring member, the cleaning member, or the like, which affects the detection result of the developer abundance detection sensor, the rotation around the developer abundance detection sensor is instantaneously performed. According to the present invention, even if the developer is sparse and the developer is still present, but the developer abundance detection sensor may erroneously detect "no developer", the number of times of sampling Of these times, the amount of developer can be detected while considering how many times such a situation occurs, so even during the operation of the stirring member or the cleaning member, etc., with high accuracy, The presence of the developer can be detected, and a warning display or the like can be performed.

According to the present invention, a time obtained by multiplying the predetermined cycle by the predetermined number of times is a time corresponding to a generation cycle of a factor affecting a detection result of the developer abundance detection sensor. Than, and set the predetermined period and the predetermined number of times so as to be at least longer,
In addition, the predetermined number is set to a number that can achieve detection accuracy of a desired amount of the developer in the developer accommodating portion.

[0012] With this configuration, at least one sampling is performed during the predetermined number of samplings (during the sampling period).
The number of times can cause an influence on the detection result of the developer abundance detection sensor due to the above factors, and furthermore, a sampling number that can achieve a desired detection accuracy is obtained, so that it is more reliable. The amount of the developer can be accurately detected while considering the influence of the factors on the detection result.

That is, every time sampling is performed a predetermined number of times,
When there is no effect on the detection result by the factor,
It is possible to reliably avoid a situation in which the occurrence and the occurrence of a mixture of the two causes the detection accuracy of the developer abundance to be reduced, and to reduce the reliability of the detection result due to a shortage of the number of samples. Therefore, it is possible to obtain a more accurate detection result of the amount of the developer in consideration of the influence of the factors on the detection result.

According to the third aspect of the present invention, the factor that affects the detection result of the developer abundance detection sensor is an operation of a stirring member for stirring the developer in the developer accommodating portion or the developing device. A cleaning member for cleaning a surface of a developer existing amount detection sensor, which is provided to face a developer in the developer accommodating portion, is provided. During the operation of the stirring member or the cleaning member, there is a high possibility that the operation of the stirring member or the cleaning member will greatly affect the detection result of the developer abundance detection sensor. It is possible to detect the amount of the developer with high accuracy even during the operation of the stirring member or the cleaning member having a large size.

According to the fourth aspect of the present invention, the developer abundance detection sensor determines the amount of the developer present in the developer accommodating portion based on the amount of light emitted from the light emitting element received by the light receiving element. It was configured as a sensor to detect. With this configuration, it is possible to use a sensor which is inexpensive but is easily affected by the operation of the stirring member, the cleaning member, and the like, and disturbance (for example, image exposure or invasion of sunlight, etc.). Thus, cost reduction can be achieved.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 2 shows the configuration of a laser color printer as an embodiment of the image forming apparatus according to the present invention. An outline of the configuration and operation will be described. The photosensitive drum 10 provided with the OPC photosensitive layer provided in the apparatus main body 1 is driven and rotated in one direction (clockwise direction in the figure). Then, after the charge at the time of the previous print is removed, the peripheral surface is uniformly charged by the charger 12 to prepare for a new print.

After such uniform charging, the image exposure means 13 performs image exposure based on the image signal. The image exposure means 13 is rotated and scanned by a polygon mirror 131 with laser light emitted from a laser light source (not shown).
The optical path is bent by the reflection mirror 133 through the above-mentioned steps, and the latent image is formed on the peripheral surface of the photoconductor drum 10 which has been charged in advance to form a latent image on the drum surface. , Magenta
(M), cyan (C), black (K), etc. toner (paint)
A developing device 14 is provided which is filled with a developer composed of a developer and a carrier (magnetic material). First, development of the first color is performed by a developing sleeve 141 which has a built-in magnet and rotates while holding the developer. Will be

The developer is applied to the developing sleeve by a layer forming rod.
The sheet is conveyed to the developing area after being regulated to a predetermined thickness. AC is provided between the photosensitive drum 10 and the developing sleeve 141.
The bias _VAC and the DC bias _VDC are applied in a superimposed manner. Here, the potential of the exposed portion of the photosensitive drum 10
(Ground potential) is V _L , the surface potential of the charged photosensitive layer other than the exposed portion is V _H , and the DC bias potential V _DC is V _H >
By setting so that V _DC > V _L is satisfied, AC
The toner given an opportunity to leave from the carrier by a bias V _AC not adhere to the high V _H portion of the potentials than V _DC, attached to the lower exposed portion potential V _L of potential than V _DC, visualized And developed.

The developing device 14 is provided with a density sensor 142 for detecting the toner density in the developer of each color, and a toner sensor which will be described later so as to approach the reference value in accordance with the detected toner density. Hopper to developer 14
Is supplied to the toner. The concentration sensor
As the toner density detection method 142, a method of detecting a change in magnetic permeability of toner as a change in inductance is known.

After the development of the first color is completed, the image forming process of the second color (for example, magenta) is started.
The photosensitive drum 10 is uniformly charged again, and a latent image based on the image data of the second color is formed by the image exposure unit 13. For the third color (cyan) and the fourth color (black), the same image forming process as that for the second color is performed, and a total of four colors are developed on the peripheral surface of the photosensitive drum 10.

On the other hand, the recording paper P fed by the paper feed mechanism 22 from the paper feed cassette 21 is transferred to the photosensitive drum 10 and the transfer belt by the transfer belt device 30 on which the transfer belt 31 is stretched.
The multi-color image on the peripheral surface of the photosensitive drum 10 is fed to the nip portion (transfer area) 35 formed between
Moved to Here, the upstream holding roller of the transfer belt 31
A high voltage is applied to a shaft 32a of the shaft 32, and a conductive brush 34 installed at a position facing the shaft 32a with the transfer belt 31 interposed therebetween is grounded. And the transfer belt 31, and enters the transfer area while being attracted to the transfer belt 31 by the charge injected into the recording paper P from the brush 34.

The recording paper P separated from the photosensitive drum 10 is
The shaft 33b of the downstream holding roller 33 that stretches the transfer belt 31
Is separated from the transfer belt 31 while being neutralized as a counter electrode. The toner adhered to the transfer belt 31 is removed by the cleaning blade 37, and is stored in a collection box 37a or the like. The transfer belt 31 is separated from the photosensitive drum 10 around the shaft 33b of the holding roller 33 on the downstream side during the formation of the multicolor image.

Recording paper P separated from transfer belt device 30
Is transported to a fixing device 23 composed of two pressure rollers having a heater inside at least one of the rollers, and heat and pressure are applied between the two pressure rollers to melt the adhered toner. After being fixed on the recording paper P, it is carried out of the apparatus. After the transfer, the toner remaining on the peripheral surface of the photosensitive drum 10 is subjected to static elimination by the static eliminator 15 and then reaches the cleaning device 16 where the toner is scraped into the cleaning device 16 by the cleaning blade 16a contacting the photosensitive drum 10. After being carried out by the screw 16b or the like, it is stored in a collection box (not shown).

The photosensitive drum 10 from which the residual toner has been removed by the cleaning device 16 is subjected to exposure by the static eliminator 11 and then uniformly charged by the charger 12 to start the next image forming cycle. Further, if the recording paper is not separated from the transfer belt 31 and is wound around the photosensitive drum 10 and enters above the static eliminator 15, the cleaning blade 16 and the electrode wire may be damaged. A JAM sensor 36 for detecting winding is mounted near the static eliminator 15.

Further, as shown in FIG.
To supply toner of each color, magenta (M), cyan (C), and black (K) to the developing units 14A to 14D, toner hoppers 40 to 43 for filling the toners of each color, and these toners Screw 44a with built-in toner in hoppers 40-43
The transport pipes 44 to 47 for transporting the developing devices 14A to 14D by the rotation of a developing device driving motor (not shown) are mounted. In the normal print mode, the density sensor 142 detects the toner density in each of the developing devices 14A to 14D, and when the toner density in the developing device decreases, the transfer pipe from the hopper filled with the toner of the corresponding color. By driving and rotating a conveying screw inside the developing device, toner is supplied to the developing device via a conveying pipe, and the toner concentration is controlled to a level suitable for development.

Respective toner hoppers 40 to 43 are provided with remaining amount sensors 50 to 53 as developer amount detecting sensors for detecting the remaining amount (existing amount) of toner (developer) in the hopper. At the same time, in order to prevent the toner from coagulating in the hopper, for example, paddles 54 to 54 that are rotated and driven in the hopper in conjunction with a conveying screw or the like when supplying the toner to the developing device.
57 is installed. Further, solenoids 58 to 61 for preventing excessive replenishment for opening and closing the toner replenishing port are mounted on the upper portion of the hopper to prevent excessive replenishment of toner.

The remaining amount sensors 50 to 53 are constituted by, for example, piezo elements or the like. If toner is present at a position higher than the mounting position of the remaining amount sensors 50 to 53, a signal "H" indicating the presence of toner is output. When the toner drops to a position lower than the mounting position, a signal "L" indicating that the toner is absent (insufficient) is output. By the way, the remaining amount sensor 50 ~
Other than the above, a remaining amount sensor 53 using a microswitch, a sensor detecting the remaining amount using the dielectric constant of the developer, or the like may be used. Further, for example, a light emitting element A shown in FIG. The light sensor may be a sensor that includes an optical sensor composed of a light-emitting element A and a light-receiving element B, and that detects the amount of developer present based on the amount of light emitted from the light-emitting element A and received by the light-receiving element B.

In the above configuration, the toner hopper
40 to 43 or each collection box corresponds to the developer accommodating section according to the present invention. The remaining amount sensors 50 to 53 correspond to the developer presence amount detection sensors according to the present invention, and the paddles 54 to 57
Corresponds to the stirring member (or cleaning member) according to the present invention. Here, the toner hopper 40 by the remaining amount sensor 50 is used.
The remaining amount (existing amount) detection processing of the Y color toner and the warning processing performed when the remaining amount is detected to be insufficient will be described with reference to the flowchart of FIG. This flow is executed at a predetermined toner remaining amount detection timing as in the related art.

By the way, CPU, various ROM, RAM
A control unit (not shown) of the image forming apparatus configured to include the above and the like executes the flowchart of FIG. 5, whereby the control unit performs the sampling unit and the developer presence amount according to the present invention. The function as the detecting means is provided by software. That is, in step (denoted as S in the figure, the same applies hereinafter) In step 1, it is determined whether the stirring paddle 54 (or the cleaning mechanism) is operating.

If YES, proceed to step 2, NO
If this is the case, a normal developer abundance detection control for detecting the remaining amount of toner in the toner hopper 40 based on the output signal (detection result) of the remaining amount sensor 50 is executed by a method similar to the related art. In step 2, it is determined whether or not 10 ms has elapsed since the stirring paddle 54 was operated (or since the previous sampling). If YES, proceed to Step 3, and if NO, wait until 10 ms elapses.

In step 3, the output signal of the remaining amount sensor 50 is sampled and the number of samplings (X) is counted up (X + 1 = X). Then, the number of times of sampling (X) is stored in NVRAM (Non-Volatile RAM). In step 4, it is determined whether or not the output signal (detection result) of the remaining amount sensor 50 indicates that there is no toner.

If YES, the process proceeds to Step 5, and if NO, Step 5 is skipped and the process proceeds to Step 6. In step 5, the toner absence counter (Y) is counted up (Y + 1 = Y). Then, the count value (Y) after the count-up is stored in the NVRAM.

In step 6, the number of samplings (X)
Is larger than a predetermined value A (X> A).
The predetermined value A is set to a value at which the stirring paddle 54 makes at least one rotation. If YES, proceed to Step 7; if NO, return to Step 2 and repeat the above steps until the number of samplings (X) becomes larger than the predetermined value A.

In step 7, the toner absence count value (Y) / the number of samplings (X) is calculated.
It is determined whether or not the value is larger than a predetermined value B (Y / X> B).
The predetermined value B is a threshold value for determining the absence of toner. If YES, it is determined that there is no toner, and the process proceeds to step S8. On the other hand, if NO, it is determined that there is toner, and the present flow ends.

In step S8, a warning is displayed indicating that the remaining amount of toner is low or no, or the image forming operation is urged to stop, or the toner is automatically replenished. In step 9, the number of times of sampling (X) and the count value of no toner (Y) are cleared, and this flow ends. That is, in the present embodiment, as described above, sampling is performed a predetermined number of times, and a ratio (Y / X) of the number of times (Y) in which the sampling result is “no toner” among the number of times of sampling (X) is obtained. Only when this ratio (Y / X) is larger than the predetermined value B, it is determined that "no toner".

In this way, for example, the toner (developer) around the remaining amount sensor 50 becomes momentarily sparse due to the operation of the stirring paddle 54, and it is as if "toner (developer) is still present. No toner (developer) ", and the remaining amount sensor 50 may erroneously detect the amount of toner. Since the presence / absence (existence amount) of the developer can be detected, the presence / absence (existence amount) of the toner (developer) can be detected with high accuracy even while the stirring paddle 54 is operating. Become.

When a remaining amount (existing amount) sensor as shown in FIG. 4 is used, during the detection of the remaining amount, toner (development) is caused by disturbance light (for example, image exposure or invasion of sunlight). Agent) still exists, but there is a fear that it will be detected as "no toner (developer)",
There is a possibility that the light-emitting element A and the light-receiving element B may be blocked between the light-emitting element A and the light-receiving element B. In this case, the toner absence counter (Y) / the number of samplings (X) is calculated and the Y / X
Is greater than a predetermined value B (Y / X> B), the presence or absence of toner (developer) is determined. Is considered, the presence or absence (existence amount) of the toner (developer) can be detected, so that the existence amount (presence or absence) of the developer can be detected with high accuracy.

As described above, during operation of the stirring paddle or the cleaning member which affects the detection result of the remaining amount sensor, the output of the remaining amount sensor outputs an insufficient amount of toner (developer). The output signal of the remaining amount sensor is sampled a predetermined number of times at a predetermined cycle without immediately determining that there is no developer or giving a warning. Was based on
Since the determination of “with or without the developer” is made or a warning is given, it is possible to reliably prevent a false detection associated with the operation of the stirring paddle and the cleaning member, and thus a false warning display. The detection accuracy of the remaining amount (existence amount) of the toner can be greatly improved, and the reliability of warning display and the like can be improved.

In the above description, the case where the amount (remaining amount) of the Y color toner is detected has been described as a representative, but M, C, K are detected.
The same processing as in the flowchart of FIG. 5 can be performed when detecting the existing amount (remaining amount) of a color. In the above embodiment, the toner hopper 40
The case where the remaining amount (existence amount) of the toner in the toner cartridge 43 is detected has been described, but whether the toner is full in the collection box for collecting the toner removed from the photosensitive drum 10 and the transfer belt 31 is determined. Is detected, it is possible to perform the same processing in consideration of the operation of the cleaning member or the like that affects the detection result, disturbance light, and the like.

By the way, not only during the operation of the stirring paddle,
Even while the stirring paddle is stopped, it is possible to omit step 1 in the flowchart of FIG. 5 and perform the processing of step 2 to step 9.

[0041]

As described above, according to the apparatus for detecting the amount of the developer present in the image forming apparatus according to the first aspect, the influence of the influence (for example, the operation of the stirring member or the cleaning member, the disturbance, etc.) may cause an instant. Even if the developer abundance detection sensor erroneously detects, the detection result of the developer abundance detection sensor is sampled a predetermined number of times at a predetermined cycle without immediately employing such erroneous detection. , Based on how many times the sampling results are the same,
Detects the amount of developer in the developer container, eliminating erroneous detection of the sensor for detecting the amount of developer as much as possible, thereby greatly improving the accuracy of detecting the amount of developer. And at the same time, the reliability of a warning display and the like can be improved.

According to the second aspect of the present invention, each time sampling is performed a predetermined number of times, a case where the factor does not affect the detection result and a case where the factor does not affect the detection result are mixed. It is possible to reliably avoid a situation in which the detection accuracy of the abundance is reduced, and to reliably avoid a situation in which the number of samples is insufficient and the reliability of the detection result is reduced. It is possible to obtain a more accurate detection result of the amount of the developer present in consideration of the influence on the detection result.

According to the third aspect of the present invention, even when the stirring member or the cleaning member having a large influence on the detection result of the developer abundance detection sensor is in operation, the influence can be reliably eliminated. This makes it possible to detect the amount of the developer with high accuracy. According to the invention described in claim 4, the detection accuracy of the sensor that detects the amount of the developer in the developer accommodating portion based on the amount of light emitted from the light emitting element at the light receiving element is improved. Therefore, the possibility of adopting the sensor can be increased, and the possibility of cost reduction can be increased.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the configuration and functions of the present invention.

FIG. 2 is a longitudinal sectional view showing the overall configuration of the color laser printer according to one embodiment of the present invention.

FIG. 3 is a cross-sectional view showing a part of the printer.

FIG. 4 is a diagram illustrating a remaining amount sensor (a developer existing amount detecting sensor) using a light emitting element and a light receiving element, and a stirring paddle (or a cleaning member).

FIG. 5 shows the remaining amount (existence amount) of the developer in the embodiment.
9 is a flowchart illustrating a detection process, a warning process, and the like.

[Explanation of symbols]

 1 Apparatus main body 14 Developing device 37a Collection box (developer accommodating section) 40-43 Toner hopper (developer accommodating section) 50-53 Remaining amount sensor 54-57 Paddle A Light emitting element B Light receiving element

Claims (4)

[Claims] 1. An apparatus for detecting the amount of developer in an image forming apparatus including a developer accommodating section for accommodating a developer, the developer detecting an amount of developer in the developer accommodating section. An abundance detection sensor; sampling means for sampling a detection result of the developer abundance detection sensor in a predetermined cycle; sampling by the sampling means a predetermined number of times;
A developer abundance for detecting the abundance of the developer in the developer accommodating portion based on the number of times of sampling and the number of times the detection result of the developer abundance detection sensor becomes the same during the predetermined number of times of sampling; A developer detection device for an image forming apparatus, comprising: a detection unit. 2. A time obtained by multiplying the predetermined cycle by the predetermined number of times is longer than a time corresponding to a generation cycle of a factor affecting a detection result of the developer abundance detection sensor.
The predetermined cycle and the predetermined number of times are set so as to be at least long, and the predetermined number of times is set to a number that can achieve detection accuracy of a desired amount of the developer in the developer accommodating portion. 2. The apparatus according to claim 1, wherein the amount of developer is detected. 3. A factor affecting the detection result of the developer abundance detection sensor includes an operation of a stirring member for agitating the developer in the developer accommodating section, or a factor of the developer abundance detection sensor. 3. The device according to claim 2, wherein the operation is a cleaning member for cleaning a surface of the detection unit provided facing the developer in the developer storage unit. 4. A sensor according to claim 1, wherein said developer abundance detection sensor is a sensor for detecting the abundance of developer in said developer accommodating portion based on the amount of light emitted from a light emitting element received by a light receiving element. 5. The apparatus according to claim 1, wherein the developer is present in the image forming apparatus.