JPH0446429B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD The present invention relates to a copying machine that requires filling with replenishment developer and has a warning means for instructing the filling of the replenishment developer.

BACKGROUND OF THE INVENTION The mainstream of copying machines currently in practical use is an electrophotographic copying machine. In these copying machines, a developer consisting of a mixture of toner and carrier is used to develop the electrostatic latent image. Replenishment developer, specifically replenishment toner, is automatically and sequentially replenished for the subsequent developer. By the way, in these copying machines, when the replenishment developer filled inside the machine is used up, the toner concentration in the developer decreases as the electrostatic latent image develops, and as a result, the image density decreases. This will have an adverse effect on the copied image, including a decrease in the quality. For this reason, these copiers issue a warning instructing the operator to refill replenishment developer when the replenishment developer filled inside the machine is used up. Generally, they have the means to do so.

The most common warning means is a warning lamp provided on the operation panel of the copying machine, and the alarm lamp is installed on the operation panel of the copying machine. Turns on only when the amount of replenishment developer remaining in the tank is small.
It's starting to look like it's being done. The relationship between changes in the toner concentration in the developer and the timing of turning on the warning lamp in an electrophotographic copying machine having such a warning means will be explained with reference to FIG. 1 as follows.

In FIG. 1, the vertical axis shows the toner concentration in the developer, the horizontal axis shows the number of copies made by the electrophotographic copying machine, and Actual A shows the relationship between the two. First of all,
Until the replenishment developer is completely consumed,
That is, the toner concentration in the developer is maintained at a predetermined value of to until the point _P2 in FIG. 1 is reached. and,
It gradually decreases after being completely consumed. here,
Normally, the warning lamp is turned on before the replenishment developer is completely consumed, so the time point at which the warning lamp is turned on is represented by _P1 in FIG.

As is clear from Figure 1, even though the warning lamp is turned on, the toner concentration in the developer does not _immediately decrease;
-a) Copying of sheets can be carried out as usual. Also,
Even after the supplied developer is completely consumed, the toner concentration in the developer does not drop suddenly.
P ₄ points, that is, until the toner concentration value decreases to the value t ₂ below a certain tolerance value, (d-b)
Copies of a number of sheets can be made with an image quality that is acceptable for practical use. Of course, the image quality gradually deteriorates as the toner density value deviates from the desired value of to, but unless you are copying an original with many halftones, such as a photograph, this deterioration will not occur. is small. In a typical desktop electrophotographic copying machine, the value of (da) is about 800 to 100 in _A4 size.

For this reason, the operator must ensure that the warning lamp is turned on.
It is common practice to start the copying operation and obtain a copy without immediately filling the replenishing developer with the developer. By the way, since copiers installed in general offices are operated by many people all the time, if the warning lamp is already on,
An operator who is about to start copying cannot know when the warning lamp is turned on and how much copy has been made since then. For this reason, as a result of a large number of copies being made after the warning lamp is turned on, the toner concentration in the developer drops below the _t2 value, resulting in copies with image quality that is no longer suitable for practical use. Occasionally, a problem occurred in which a copying operation was started without knowing that there was no such thing, and a large number of unnecessary copies were created.

These processes are not only a waste of time for the operator, but also result in the resulting copies being destroyed, which is uneconomical. Furthermore, since the operator does not fill the copying machine with replenishing developer at this point, the problem may also be caused by the operator who uses the copying machine later.

OBJECT OF THE INVENTION An object of the present invention is to provide a copying machine that can prevent the occurrence of the above-mentioned problems. That is, it is an object of the present invention to provide a copying machine that can accurately set the number of remaining copies that will yield good copies and prevent the production of unnecessary copies.

SUMMARY OF THE INVENTION The present invention provides a copy paper size detecting means for detecting the size of the loaded copy paper in a copy paper that can be loaded with copy paper of different sizes, and a copy paper size detection means for forming a developed image of a developer on the copy paper. a developing device accommodating developer for the purpose of the present invention; a remaining amount detecting means for detecting the remaining amount of the developer; and a warning means for instructing the filling of the developer based on the detection result of the remaining amount detecting means; a storage means for storing an allowable number of copies corresponding to the copy paper size detected by the copy paper size detection means when a warning is issued by the warning means; and after the warning is issued; a counting means for counting the number of copied copies; after the warning is issued, a predetermined value is set to an area value corresponding to the size of the copy paper detected by the copy paper size detection means; calculating the number of consumed copies obtained by multiplying the number of copies counted by the counting means, and subtracting the consumed number of copies from the allowable number of copies stored in the storage means to set the remaining number of copies; a calculation means for prohibiting further copying operations when it is determined that the number of remaining copies has reached a predetermined value; Before the prohibition, when the copy size detection means detects that the size of the copy paper has been changed, the remaining amount set in the calculation means before the change in the size of the copy paper is detected. The present invention also includes a changing means for changing the number of copies in accordance with the changed size of copy paper, thereby prohibiting the production of unnecessary copies as described above.

Embodiment As an embodiment of the copying machine according to the present invention, the second to
The powder image transfer type electrophotographic copying machine will be explained with reference to FIG. Note that the copying machine according to the present invention is not limited to these types as long as it requires replenishment of developer.

First, referring to FIG. 2, the structure of the developing device in the above embodiment will be explained as follows. In FIG. 2, the developing device D _e is installed facing the circumferential surface of the electrophotographic photosensitive drum 1 which is rotationally driven in the direction of the arrow d, and the developing device D e is installed opposite to the circumferential surface of the electrophotographic photosensitive drum 1, which is rotated in the direction of the arrow d. The electrostatic latent image corresponding to the image is developed and visualized. This developing device D _e is roughly divided into a developing section and a developer replenishing section, and in the developing section, a developing sleeve 3, a magnetic roller 4, and a bucket troller 5 are each rotatably installed in a developing tank 2. . The developing sleeve 3 and the magnetic roller 4 are driven to rotate in the direction of the arrow e when developing the electrostatic latent image, and transport the magnetic brush made of the developer 6 formed on the circumferential surface of the developing sleeve 3 in the opposite direction of the arrow e. Photosensitive drum 1 by magnetic brush
It rubs against the circumferential surface of the Further, the bucket troller 5 supplies the developer tank developer 6 contained in the developer tank 2 onto the circumferential surface of the developing sleeve 3 by being rotationally driven in the direction of arrow f. The developer 6 is a so-called two-component magnetic developer made of a mixture of a small-diameter magnetic carrier and an insulating toner.

On the other hand, in the developer replenishment section, a replenishment developer 6' is stored in a replenishment developer storage tank 7.
This replenishment developer 6' is reinforced with respect to the developer 6 contained in the developer tank 2 by a replenishment roller 8 which is rotationally driven in the direction of arrow g at appropriate times. Therefore, the toner concentration in the developer 6 contained in the developer tank 2 is maintained at the value to. Further, a replenishment developer stirring rod 9 swinging in the direction of arrow h is provided in the tank 7 to prevent crosslinking of the replenishment developer 6' within the tank 7. Further, a remaining amount detecting element 10 is attached to the side wall of the tank 7 to detect the remaining amount of the replenishing developer 6'. This remaining amount detection element 10 has a diaphragm that vibrates in the direction of arrow i on the right end surface in the figure, that is, the surface facing the replenishment developer 6' in the tank 7, and the amplitude of the diaphragm changes depending on the magnitude of the amplitude of the diaphragm. Therefore, the remaining amount of replenishing developer 6' is detected. Specifically, when the top surface of the replenishment developer 6' stored in the tank 7 becomes below the dashed line B in the figure, a toner empty display provided in the operation panel 11 (to be described later) is displayed. Warning lamp in frame 14
Turn it on. Details regarding this specific control will be described later with reference to the flowchart shown in FIG. Note that the replenishment developer 6' is the developer 6
It consists only of replenishment toner having the same composition as the toner mixed therein.

Next, referring to FIG. 3, the flow related to the control of the embodiment using the microcomputer will be explained item by item as follows. In the flow described below, the replenishment developer 6' stored in the replenishment developer storage tank 7 is
A warning lamp is turned on when the top surface becomes below dashed line B, and then when 600 sheets of _A4 size are copied, the warning lamp flashes, and
Although the start of the next copying operation is prohibited when 200 copies have been made, the flow related to the control of the copying machine of the present invention is not limited to such a flow.

(a) When the top surface of the replenishment developer 6' stored in the replenishment developer storage tank 7 is above the dashed-dotted line B; When the power is turned on, various processes related to the copying operation are performed in the step. The processing related to this copying operation includes turning on and off each image forming element after the print button 17 provided in the operation panel 11 is pressed.
Then, following the step, it is determined in the step whether or not copying of one sheet has been completed. Here, if it is determined that copying of one sheet has been completed, the copy completion flag Fc is set to "1" in step, and the process then moves to step. On the other hand, if the completion of the copying is not determined, the flag Fc is not set and the process directly moves from step to step. Specifically, the above-described determination is made based on whether or not the copy paper is discharged outside the machine, and in the embodiment described above, a copy paper conveyance path near the copy paper ejection port is provided for this purpose. A paper passage detection mechanism is used. By the way, in the step, the presence or absence of the replenishment developer 6' in the replenishment developer storage tank 7, specifically, the remaining amount detection element 10 detects the upper surface of the replenishment developer 6' stored in the tank 7. It is determined whether or not the dashed line B is above the dashed line B.
In the case of (a) above, it is determined that replenishment developer 6' is present,
Move on to the next step. Then, in step it is determined whether the toner empty flag Fc has already been set. The toner empty flag Fc is set in a step to be described later, but in the case of (a), the flag Fc has not been set yet and the process moves from step to step. As a result, the copy completion flag Fc is reset in step
Further, in subsequent steps, various processes other than those related to copying operations on copy paper are performed,
You will have to return to the step again. The processing includes turning on and off the heat source of the heat fixing device. Note that the flow between steps ~ and ~ is also common to cases (b) to (e) described later, so the explanation thereof will be omitted in cases (b) to (e) described later.

(b) When the top surface of the replenishment developer 6' stored in the replenishment developer storage tank 7 is below the dashed dot line B; this point is represented by point P ₁ in Figure 1, and this point Thereafter, everything is transferred from step to step. Then, in step it is determined whether the warning flag Fw has already been set. The warning flag Fw is set in the step described below, but in the case of (b) above, the warning flag Fw has not been set yet.
It moves from step to step. Also, in the step, the toner empty
It is determined whether the flag Fe has already been set. By the way, the setting of the flag Fe is done in the step described later.
In the case of (b), the flag Fe is not set yet, and the steps from step to
After that, it moves on to the step. In the step, the warning lamp in the toner empty display frame 14 provided in the operation panel 11 of the copying machine is turned on to instruct the operator to transfer the replenishment developer 6' into the replenishment developer storage tank 7. While encouraging filling,
In the step, the flag Fc is set to "1", and in a further step, a predetermined allowable number of copies is set to the counter.
Here, the allowable number of copies set for the counter differs depending on the size of copy paper loaded in the copier. For example, if _A4 size copy paper is loaded, A copy paper size detection mechanism installed in the copy paper size detection mechanism detects this and sets the number of copies to 600.
Incidentally, in the case of _A3 size, _B4 size, and _B5 size, the numbers of sheets are set at 300, 400, and 800, respectively.
Note that the number of these sheets is inversely proportional to the area ratio of each size, and when all the above numbers are copied, the total copy area is equal to each other. On the other hand, following the above step, it is determined in the step whether the contents of the counter have been decremented to "0", but since this is immediately after the number of sheets has been set in the step, there is a transition from step to step. It is then returned through the steps to repeat the next cycle.

Note that from the next cycle onward, the toner empty flag Fe has already been set to "1".
It's been a long time, so from step to step 〓〓
〜〓〓 and then move on to the step. Step〓〓
.about.〓〓 is a step for changing the contents of the counter in accordance with the change in the size of the copy paper, and decrementing the contents of the counter by "1" when one sheet of copying is completed. Specifically, in step <<>, it is determined whether or not the size of the copy paper has been changed. Here, if it is not determined that the size of the copy paper has been changed, the contents of the counter are not changed and the process directly moves from step 〓〓 to step 〓〓. on the other hand,
If the detection mechanism detects a change in the size of the copy paper, and as a result it is determined that the size of the copy paper has been changed, the content of the counter is changed in step based on the formula below, and then the step 〓〓Move to 〓〓.

Contents of counter after change =
Contents of the counter before change/S' However, if the contents of the counter after change are a small number, the decimal part is rounded down and only the integer part is set in the counter.

S...Area value corresponding to the size of copy paper before change S'...After change The above area value is stored in advance in the RAM of the microcomputer, and A ₃ , A ₄ ,
A ₅ , B ₄ , B ₅ , B ₆ ... are respectively 16.8, 4, 12, 6,
Values such as 3... etc. correspond. Further, in step <<>, it is determined whether the copy completion flag Fc has already been set, that is, whether one copy has already been completed. If it is determined that the copying of one sheet has been completed, the content of the counter is decremented by "1" in step 〓〓, and the process proceeds to step 〓〓. Go directly to step without going through 〓. Here, in the step, after the allowable number of copies is set as described above, the number of copies is 600 in _A4 size.
The content of the counter does not become "0" until the copying of the entire copy is completed, and until then, the process moves directly from step to step, and the same flow is repeated every time.

(c) After the warning lamp turns on, change to _A4 size.
When 600 copies have been made; this point is represented by ₃ points in Figure 1, and the toner concentration in the developer is at a value t ₁ that is greater than a certain tolerance value t ₂ . Although copies can be made with an image quality that is acceptable for practical use, the image quality gradually deteriorates as copying continues. At this point, it is determined in step that the contents of the counter have become "0", and the process moves from step to step. Then, in the step, the warning lamp that has already been turned on is turned on and off, to further urge the operator to fill the replenishment developer storage tank 7 with the replenishment developer 6' in a manner different from the case (b) above. . Further, in a step, a warning flag Fw is set to "1", and in a step, a limit number of copies is set to a counter. The limit number of copies set here is 1/3 of the above-mentioned allowable number of copies, and _A4
If copy paper of the same size is loaded, 200 sheets will be set. The specific method for setting the number of sheets is substantially the same as the method for setting the number of sheets in the step described above. On the other hand, following the above step, it is determined in the step whether the contents of the counter have been decremented to "0", but since this is immediately after the number of sheets has been set in the step, there is a transition from step to step. It is then returned through the steps to repeat the next cycle.

In addition, from the next cycle onward, since the warning flag Fw has already been set and becomes "1", the process moves from step to step. These steps~
correspond to the steps 〓〓 to 〓〓, respectively, and since they are the same, their explanation will be omitted. In addition,
After the limit number of copies is set as described above in the step, the content of the counter remains "0" until the copying of 200 _A4 size sheets is completed.
Until then, the process moves directly from step to step, repeating the same flow each time.

(d) After the warning lamp flashes, 200 _A4 size copies have been made; this point is represented by point P ₄ in Figure 1, and the image has reached a point where it can no longer be used for practical purposes. Copying can only be done with high image quality. At this point, the process moves from step to step. Then, in the step, it is determined that the contents of the counter have become "0", and in the step, the start of the next copying operation is prohibited.In other words, even if the print button 17 is pressed, the copying operation will not be started. Therefore, the creation of unnecessary copies itself is prohibited.The specific process for prohibiting the start of the copying operation is to set a copy prohibition flag in the step mentioned above, and to set the copying prohibition flag. In this case, it is also possible to skip the flow related to on-off control of each image forming element after pressing the print button 17 in the step.In this case, in the step below, the copy prohibition flag is reset. In addition, it is efficient to skip over the flow related to steps ~ and ~ when the copy flag is set.

(E) When the replenishment developer 6' is filled into the replenishment developer storage tank 7 after the start of the copying operation is prohibited, or when the replenishment developer 6' is filled after the warning lamp is turned on; When this happens, the remaining amount detecting element 10 detects this, and the process moves from step to step. At this point, it is determined whether or not the toner empty flag Fe has already been set.
Since Fe is set to "1", the transition from step to step is made through steps 〓〓 to 〓〓. In the step 〓〓, the warning lamp is turned off, and in the step 〓, the flag Fe and the warning flag Fw are reset. It will be canceled.
Then, it is passed from step to step and returned to step, and in the next cycle, the
The same flow as in case (a) will be repeated.

The above is an explanation of the flow related to control in the embodiment. In the above flow, when the power of the copying machine is turned off, the contents of the counter and the status of each flag are saved in a memory backed up by a battery. Next, referring to FIG. 4, the structure of the operation panel in the above embodiment will be explained as follows. Fourth
In the figure, a plurality of display frames 12 to 15 including a toner empty display frame 14 and a digital display number display lamp 16 are provided within the operation panel 11. Further, on the left side of the print button 17 in the operation panel 11, a check button 18 and a continuous copy number setting button 19 are provided. The number display lamp 16 normally displays the set number of continuous copies, but in the embodiment described above, when the check button 18 is turned on, it is assumed that the toner empty flag Fe or warning flag Fw has already been set. The content of the counter is displayed only when the copy paper size is set, and the operator is informed of the number of copies left in the allowable number of copies or the number of copies left in the limit depending on the size of the copy paper. It's getting old. Therefore, after the warning lamp is turned on, the operator can know in detail to what extent copies can be made with image quality that is acceptable for practical use by turning on the check button 18.

The above is an explanation of the embodiment of the copying machine according to the present invention, but this embodiment can be modified in various ways. For example, regarding the remaining amount detection means for detecting the remaining amount of replenishment developer, instead of directly detecting the remaining amount of replenishment developer 6' in the replenishment developer storage tank 7,
Conversely, it may be detected that the replenishment developer 6' is completely consumed and the remaining amount is zero based on a decrease in the toner concentration in the developer in the developer tank 2. Furthermore, regarding the changing means for changing the mode of replenishment developer filling instruction by the warning means, instead of changing the warning lamp from a constantly lit state to a blinking state, warning lamps of different colors are sequentially turned on. The color tone may be changed. in particular,
As the amount of copies stored in the storage means increases, the color tone of the warning lamp may be changed from green to yellow, or further from yellow to red. Alternatively, the blinking interval of the warning lamp may be gradually shortened as the amount of copies stored in the storage means increases. In the above embodiment, in order to display the remaining number of allowed copies or limited number of copies, the amount of copies is stored in the form of subtraction by the storage means, but the amount of copies is stored in the form of subtraction. In addition, it is not necessary to store the copy amount in two stages, such as the permissible number of copies and the limit number of copies.

Effects of the Invention In the copying machine according to the present invention, if the size of the copy paper to be used is changed after the instruction to fill the replenishment developer is given by the warning means, the copying operation will be performed accordingly. Since it has a changing means for changing the number of remaining copies that can be made before being prohibited, it is possible to accurately set the number of remaining copies that will produce good copies, and it is possible to prevent copies with poor image quality. is completely prevented from being created in vain.

[Brief explanation of drawings]

FIG. 1 is a diagram schematically showing the relationship between the toner concentration in the developer and the number of copies after an instruction is given to add replenishment toner in an electrophotographic copying machine, and FIG. Drawings showing the structure of the developing device in the embodiment of the copying machine, FIG. 3 is a flowchart regarding control of replenishment developer filling instructions in the embodiment, and FIG. 4 shows the main structure of the operation panel in the embodiment. FIG. D _e ...Developing device, 6...Developer, 6'...Replenishment developer, 10...Remaining amount detection element, 11...Operation panel, 14...Toner empty display frame.

Claims (1)

[Scope of Claims] 1. In a copy paper that can be loaded with copy paper of different sizes, copy paper size detection means for detecting the size of the loaded copy paper; and for forming a developed image of a developer on the copy paper. a developing device containing a developer; a remaining amount detecting means for detecting the remaining amount of the developer; a warning means for instructing to fill the developer based on the detection result of the remaining amount detecting means; and the warning. When a warning is given by means,
a storage means for storing the permissible number of copies corresponding to the copy paper size detected by the copy paper size detection means; a counting means for counting the number of copies made after the warning is issued; After the above-mentioned warning is issued, the area value corresponding to the size of the copy paper detected by the copy paper size detection means is multiplied by a predetermined value and the number of copies counted by the counting means. calculating the consumed number of copies, and subtracting the consumed number of copies from the allowable number of copies stored in the storage means;
a calculation means for setting the number of remaining copies; a prohibition means for prohibiting further copying operations when it is determined that the number of remaining copies has reached a predetermined amount; , and before the start of the copying operation is prohibited, when the copy size detection means detects that the size of the copy paper has been changed, the above calculation is performed before it is detected that the size of the copy paper has been changed. 1. A copying machine comprising: changing means for changing the number of remaining copies set in the means in accordance with the changed size of copy paper.