JPH07181841A - Image forming device - Google Patents

Abstract

PURPOSE:To precisely grasp how many sheets of image forming operation can be executed more when the quantity of developer is reduced. CONSTITUTION:A detection means detecting that the developer becomes equal to or under the prescribed quantity and generating a signal, is provided. After the detection signal is generated, time display 37 of a control panel 30 showing. that the developer is nearly ended is turned on. Simultaneously, the number of image forming feasible sheets thereafter is calculated every image forming action. Then, the calculated result is displayed on a display part 34. Besides, when the number of image forming sheets exceeding the number of sheets displayed on the display part 34 is set by ten-key 32, an alarm is issued or the number of sheet which can be set, is restricted within the number of image forming feasible sheets.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus capable of forming a predetermined number of images even when the amount of developer becomes insufficient.

[0002]

2. Description of the Related Art In an image forming apparatus that uses a developer to form a visible image, such as a copying machine or a laser beam printer that uses an electrophotographic system, the remaining amount of the developer (toner in this case) is used. A sensor is provided in the toner storage unit for detection, and when it detects that the remaining amount of toner has reached a predetermined amount, the toner near end display is lit on the display unit on the operation panel, and the toner end is close to the operator. I was informed.

[0003]

However, in such a method, since it is not known how many sheets can be printed after the toner near-end display is turned on, the operator sets the number of sheets to be printed and starts printing. In some cases, the toner was exhausted in the middle of printing when the user left the machine, and the printing was not finished when the operator returned. Alternatively, when a user wants to print a large amount in a hurry, the toner end may occur on the way and the toner must be replaced in a hurry.

The present invention has been made in view of the above points, and accurately determines how many more images can be formed in the image forming apparatus as described above when the remaining amount of the developer is low. The purpose is to be able to grasp.

[0005]

In order to achieve the above-mentioned object, the present invention comprises a setting means for setting the number of image forming sheets, a display means for displaying various information regarding the apparatus, and a storage means for storing a developer. An image forming apparatus having a detection means for detecting that the amount of the developer in the accommodating means has fallen below a predetermined amount and generating a detection signal, after the detection signal is generated by the detection means, after every image formation. And a display control means for displaying the image formable number obtained by the calculating means on the display means, and the number set by the setting means exceeds the image formable number And a warning means for issuing a warning to.

Alternatively, the same image forming apparatus as described above may be provided with a means for limiting the number of sheets that can be set by the setting means to within the number of sheets for image formation.

It is to be noted that the calculating means is a means for calculating the amount of developer used from the image area ratio of the formed image and subtracting the remaining amount of the developer from the predetermined amount so as to calculate the number of imageable sheets thereafter. Good.

Further, a plurality of the detecting means are installed at different height positions in the accommodating means, and the display control means has means for displaying the presence or absence of a detection signal from each of the detecting means on the display means. The calculating means may be a means for starting the calculation after the detection signal is generated by the detecting means of the lowest order.

Further, in the above-mentioned image forming apparatus, a humidity measuring means is provided in the vicinity of the accommodating means, and the calculating means corrects the calculation of the number of image formable sheets according to the humidity measurement value by the humidity measuring means. Means may be provided.

[0010]

According to the above-mentioned invention, when the amount of the developer becomes less than a predetermined amount, the detection means generates a detection signal, and after that, for each image formation, it calculates and displays how many more images can be formed, and If the set number of image formations exceeds the calculated number of images that can be formed, a warning is given, or the setting that exceeds the number of images that can be formed is disabled so that even if the remaining amount of developer becomes insufficient. , It is easy to understand how many more images can be formed, and it is possible to set the number of sheets by mistake.

Further, the calculation of the number of images that can be formed on the image is calculated from the remaining amount obtained by calculating the developer usage amount from the image area of the formed image and subtracting it from the predetermined amount of the developer, or the humidity inside the machine at that time. By performing the correction based on the measured value, it is possible to notify the more accurate number of image-formable sheets. Further, it is also possible to detect the remaining amount of the developer in a plurality of stages by a plurality of detecting means provided at different height positions in the containing means for containing the developer, and display it.
Thereby, it is possible to know the decrease in the developer at a relatively early stage.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a copying machine which is an electrophotographic image forming apparatus will be specifically described below with reference to the accompanying drawings. FIG. 2 is a cross-sectional view of the copying machine. A scanner section 2 is provided above the copying machine main body 1, and an exposure section including a polygon mirror 3, an image forming optical system 4 and a reflecting mirror 6 is arranged below the scanner section 2. ing. The photoconductor drum 7 is arranged in the central portion and is rotated in the arrow direction by a drive motor (not shown). Around the photoconductor drum 7, a charging charger 8, a developing device 9, a transfer charger 12, and a cleaning unit 13 are arranged.

The document image information read by the scanner unit 2 is oscillated as a laser beam 5 modulated by a laser diode (not shown), and the polygon mirror 3 and the image forming optical system 4 are generated.
Then, an image is formed on the photosensitive drum 7 through the reflection mirror 6 and the photosensitive drum 7 is exposed and scanned. The photoconductor drum 7 is uniformly charged by the charging charger 8 before exposure,
By performing the above-described exposure scanning on this charged surface, an electrostatic latent image is formed on the surface of the photosensitive drum 7. This electrostatic latent image is visualized as a toner image by the developing device 9, and is transferred by the transfer charger 12 onto the transfer paper fed from the paper feed cassette 10 or 11. The residual toner that has not been transferred is removed by the cleaning unit 13. The transfer paper on which the toner image has been transferred is sent to the fixing roller 15 by the conveyor belt 14 to fix the toner image, and then discharged to the outside of the machine.

The detailed structure of the developing device 9 is shown in FIG. The developing device 9 is roughly divided into a developing tank 16 and a toner container 17 which is a container for containing toner as a developer. When the toner concentration in the developing tank 16 becomes low, the toner replenishing roller 19 rotates and the toner container 1
Toner is replenished from 7. The supplied toner is mixed with the magnetic carrier in the developing tank 16 by the stirring roller 20. The toner is carried to the surface of the photoconductor drum 7 by the developing roller 21 and attracted to the electrostatic latent image on the photoconductor drum 7 to form a visible image on the photoconductor drum 7.

The toner container 17 is provided with a toner near-end detection sensor (hereinafter referred to as a toner sensor) 18 which is a detection means for detecting when the amount of toner contained therein becomes less than a predetermined amount. There is. When the amount of toner in the toner container 17 is reduced and the toner sensor 18 does not reach the position, the toner sensor 18 generates a detection signal.

FIG. 1 shows the main part of the operation panel of this copying machine. On the operation panel 30, a copy start switch 31, a ten key 32 for setting the number of copies, which is the number of image formations, a density setting key 40 for setting the copy density, a set number display section 33 for displaying the set number of copies,
A copyable number display unit 34, a warning lamp 35, a toner end display unit 36, a toner near end display unit 37, a paper end display unit 38, a liquid crystal display (LCD) 39 capable of displaying 20 characters, and the like are arranged.

FIG. 4 is a block diagram showing the structure of the control system of this copying machine. Main control unit 10 of this copying machine
Reference numeral 0 denotes a CPU 101 that controls the copying machine main body 1 and the scanner unit 2 shown in FIG. 2, a ROM 102 that stores control programs, and a RAM 1 that stores temporary data.
03, common data bus 104, and I / O port 105
Composed of. Scanner unit 2, printer unit (comprising polygon mirror 3, developing device 9, photosensitive drum 7, etc.) 10
6, operation panel 30, toner sensor 18, humidity sensor 2
2 exchanges data with the main control unit 100 via the I / O port 105.

Next, the operation of this embodiment will be described with reference to the flow charts of FIGS. Toner sensor 18
Generates a detection signal, the main control unit 100 recognizes that it is in the toner near end state. Toner sensor 1
Immediately after the switch 8 is turned on, or when the number of copies is set or the copy size is changed after the toner near end state, the subroutine shown in FIG. 5 is executed. First, in step S1, how many copies can be made is calculated. The toner sensor 18 uses an A4 standard document (image area ratio of black portion is 6
Since the A4 size is selected immediately after the detection signal from the toner sensor 18 is generated, the number of sheets that can be copied after that is 50 sheets. If a size other than A4 is selected, the amount of toner used per sheet is different, and therefore, the inverse ratio of the area where A4 is 1 may be multiplied. In this way, the number of sheets that can be copied is 25 in A3 size.
The number of sheets is 66 for B5 size, and 33 for B4 size. Furthermore, when the copy size is changed, the number of copies that can be made in the size before change is also multiplied by the inverse ratio of the area of the size before and after the change to calculate the number of copies that can be made in that size. You can do it. The multiplier of each size is shown in FIG.

The copyable number calculated in step 1 is displayed on the copyable number display section 34 of the operation panel 30 shown in FIG. 1 (step S2). Next, the RAM 103 is set by the number of copyable sheets and the ten key 32.
The size of the number of sets stored in is determined (step S
3) If the set number of sheets exceeds the number of sheets that can be copied, the warning lamp 35 is turned on, and a message such as “TOUCH DETANER GANARIMAS” is displayed on the LCD 39 (step S4). Also, instead of this warning display,
As in step S5 of FIG. 8, the set number of sheets may be reset to 1 so that the number of sheets that can be set thereafter is limited to within the number of sheets that can be copied.

When the copy start switch 31 of FIG. 1 is pressed, the subroutine shown in FIG. 6 is executed. When one copy is made in step S11, the copyable number is subtracted by 1 in step S12. As a result, the number of copies that can be displayed is reduced by one. Next, it is determined whether or not the number of copyable sheets has become 0 (step S13),
If the number of copyable sheets is 0, further copying is impossible, so the toner end display section 36 is turned on (step S15) and the machine is stopped (step S16). If the number of sheets that can be copied is not 0, it is determined whether the set number of sheets has been copied (step S14). If not, the process returns to step S11.

As described above, when the toner near end state is reached, the remaining number of sheets that can be copied is calculated and displayed at any time, so that it can be easily determined how many more sheets can be copied.

Next, another embodiment of the present invention will be described. In the above-described embodiment, in the process of calculating the number of copies that can be performed by the main control unit 100, the number of copies that can be copied is always decremented by one when copying one copy. However, in this embodiment, copying is performed according to the black pixel area (image area ratio) of the document. Correct the calculation of the possible number of sheets. Other configurations and operations are the same as those of the above-described embodiment. FIG. 9 is a flow chart of copy processing in this embodiment. The same steps as those in FIG. 6 have the same step numbers.

When the copy start switch 31 is pressed, one copy is made in step 21. At this time, the area of the black pixel portion in the original image read by the scanner section 2 is calculated (step S22). The area of the black pixel portion is C
It can be calculated by accumulating a value obtained by A / D converting the CD output voltage for one page. Next, the calculated black pixel area of the original and RO
In step S23, the number of copies that can be copied is calculated from the ratio (image area ratio) to the black pixel area of the standard document stored in M102 in advance. For example, the calculated black pixel area of the original is 7
If it is 4 cm ² , the area of black pixels of A4 standard original is 37 cm ^2.
Therefore, this document consumes twice as much toner as the standard document. Therefore, the number of copyable sheets may be subtracted by two.

In this way, by correcting the calculation of the number of copies that can be made according to the black pixel area ratio of the original, it is possible to more accurately determine how many more copies can be made.

Next, still another embodiment of the present invention will be described. Although only one toner sensor is provided in each of the above-described embodiments, four toner sensors 18a are provided in this embodiment.
~ 18d is provided. As shown in FIG. 10, the toner sensors 18a to 18d are arranged in the toner container 17 so as to have different positions in the height direction. 18c is shown in FIG.
It is assumed that it is located at the same position as the toner sensor 18 shown in FIG.

Each of the toner sensors 18a to 18d changes from the OFF state to the ON state when there is no toner at that position,
It shall output a detection signal. The three LEDs 37a to 37c of the toner end display section 36 on the operation panel 30 shown in FIG. 1 and the toner near end display section 37 shown in FIG. ON / OFF of toner sensor and ON / O of display of LEDs 37a to 37c of toner end display section 36 and toner near end display section 37 on operation panel 30
The relationship with the FF is shown in FIG. Toner sensor 18a-1
If all of 8d are OFF, the toner end display portion 36 and the toner near end display portion 37 are all OFF, indicating that the toner is still sufficient (step in the figure). When the toner sensor 18a is turned on, the LEDs 37a to 37c of the toner near-end display portion 37 are all turned on as shown in FIG. 11A (the turned-on LEDs are shaded) and the toner is running low. Notify that (). At this stage, for example, an amount of toner that allows 150 sheets of A4 size to be copied remains.

When the toner further decreases and the toner sensor 18b is turned on, the LED 37a is turned on as shown in FIG. 11 (b).
Turns off (). At this stage, for example, an amount of toner that can be used to copy 100 sheets of A4 size remains. Further, when the toner sensor 18c is turned on, the LED 37b turns off.
After FF, only the LED 37c is turned on as shown in (c) of FIG. 11 (). At this stage, for example, an amount of toner that can be copied for 50 A4 sheets remains. From this stage, the calculation and display of the number of sheets that can be copied is started as in each of the above-described embodiments. When the toner is exhausted and the toner sensor 18d is turned on, the toner near end display portion 37 is turned off and the toner end display portion 36 is turned off.
N (). In this state, copying is impossible and L
On the CD 39, the message "Toner is ready" is displayed.

As described above, if a plurality of toner sensors are provided and a plurality of LEDs of the toner near-end display section 37 are turned on / off corresponding to ON / OFF of the respective sensors, the toner amount can be reduced relatively early. Since it can be known, it is possible to avoid the toner end in the middle even when a large amount of continuous copying is performed, and it is also possible to prepare toner for replenishment in advance.

Further, in this embodiment, the humidity sensor 22 is provided near the developing device 9. It is known that the amount of charge of toner changes depending on the ambient humidity. When the amount of charge changes, the amount attached to the photoconductor also changes accordingly.
As shown in FIG. 13, the adhered amount of toner increases as the humidity increases, and conversely decreases as the humidity decreases. As described above, since the toner consumption varies depending on the humidity, a more accurate value can be obtained by correcting the calculation of the number of copyable sheets depending on the humidity.

FIG. 14 shows the main control unit 10 in the case where the number of sheets that can be copied is corrected and calculated according to the humidity in the machine.
It is a flowchart of the copy process by 0. The same steps as those in FIG. 6 have the same step numbers. When the toner sensor 18c shown in FIG. 10 is turned on to enter the toner near end state, the CPU is interrupted at regular intervals thereafter, and the subroutine of FIG. 14 is executed. Step S
At 31, the humidity is read from the humidity sensor 22. Next, in step S32, the number of sheets that can be copied is calculated. As shown in FIG. 13, the relationship between the humidity and the toner adhesion amount can be approximated by a linear expression. Therefore, the current toner adhesion amount at a certain humidity is used as a reference. It is possible to easily calculate the ratio of the toner adhesion amount with humidity.
For example, assuming that the humidity is 25% and the toner adhesion amount at the current humidity is 1.2 times that, 1 / 1.2 of the copyable number at the reference is the corrected copyable number. The subsequent processing is the same as that described with reference to FIG.

As described above, by providing the humidity sensor and correcting the value of the number of copies that can be made according to the current humidity, it is possible to more accurately determine how many more copies can be made. The present invention can be similarly applied to other image forming apparatuses such as an electrophotographic laser printer. In that case, it goes without saying that the number of images to be formed may be set on the host side.

[0032]

As described above, according to the present invention, when the amount of the developer becomes equal to or less than the predetermined amount, it is displayed how many more images can be formed. If the number is large, a warning will be given, or the number of images that can be formed will not be set. Therefore, it is easy to see how many more images can be formed, and the number of images can be set by mistake. Further, if the remaining image formable number is corrected according to the image area or humidity, a more accurate value can be known. Further, by displaying the amount of the developer which has run out in stages, it is possible to know the decrease of the developer at a relatively early stage, and it is possible to prevent the image formation from being abruptly stopped.

[Brief description of drawings]

1 is an external view of a main part of an operation panel of the copying machine shown in FIG.

FIG. 2 is a cross-sectional configuration diagram of a copying machine that is an embodiment of the image forming apparatus according to the present invention.

FIG. 3 is an enlarged view of the vicinity of the developing device 9 and the photoconductor drum 7 shown in FIG.

4 is a block diagram showing a configuration of a control system of the copying machine shown in FIG.

FIG. 5 is a flowchart of a subroutine executed by the main control unit 100 in FIG. 4 when changing the number of sheets / size.

FIG. 6 is also a subroutine at the time of copy processing.

FIG. 7 is a diagram showing a multiplier according to a copy size when calculating the number of copies that can be made.

FIG. 8 is a flowchart showing a partially modified example of the subroutine shown in FIG.

FIG. 9 is a flowchart of a subroutine at the time of copy processing similar to FIG. 6 in another embodiment of the present invention.

FIG. 10 is an enlarged view of the vicinity of a developing device and a photosensitive drum similar to FIG. 3 in another embodiment of the present invention.

FIG. 11 is a diagram showing a display example of the toner near-end display portion 37 on the operation panel.

FIG. 12 is a schematic diagram of the toner sensors 18a to 18d shown in FIG.
FIG. 6 is a diagram showing the correspondence between the LEDs 37a to 37c of the toner end display section 36 and the toner near end display section 37 on the operation panel.

FIG. 13 is a diagram showing the relationship between humidity and toner adhesion amount.

14 is a flowchart of a subroutine for humidity correction by the main control unit 100 in the embodiment shown in FIG.

[Explanation of symbols]

1: Copier body 2: Scanner 7:
Photoconductor drum 9: developing device 16: developing tank 1
7: Toner container 18, 18a to 18d: Toner sensor 2
2: Humidity sensor 30: Operation panel 33: Set number display section 34: Copyable number display section 35: Warning light 36: Toner end display section 37: Toner near end display section 39: LCD 100: Main control section 10
1: CPU

Claims (5)

[Claims] 1. A setting means for setting the number of images to be formed, a display means for displaying various kinds of information on the apparatus, a containing means for containing a developer, and a developer in the containing means is below a predetermined amount. An image forming apparatus having a detection means for detecting the occurrence of a detection signal and generating a detection signal, and a calculation means for calculating the number of image-formable sheets thereafter for each image formation after the detection signal is generated by the detection means; Display control means for displaying on the display means the number of image formable sheets obtained by the above, and warning means for issuing a warning when the number of sheets set by the setting means exceeds the number of image formable sheets. Image forming apparatus. 2. A setting means for setting the number of images to be formed, a display means for displaying various kinds of information on the apparatus, a containing means for containing a developer, and a developer in the containing means is below a predetermined amount. An image forming apparatus having a detection means for detecting the occurrence of a detection signal and generating a detection signal, and a calculation means for calculating the number of image-formable sheets thereafter for each image formation after the detection signal is generated by the detection means; An image forming apparatus comprising: display control means for displaying on the display means the number of image formable sheets obtained by the above; and means for limiting the number of settable sheets by the setting means to within the number of image formable sheets. . 3. The calculating means is means for calculating the amount of developer used from the image area ratio of the formed image, and calculating the number of image-formable sheets thereafter from the remaining amount of the developer subtracted from the predetermined amount. The image forming apparatus according to claim 1 or 2, characterized in that. 4. A plurality of said detection means are installed at different height positions in said housing means, and said display control means has means for displaying on said display means the presence or absence of a detection signal by said each detection means, 4. The image forming apparatus according to claim 1, wherein the calculation unit is a unit that starts calculation after a detection signal is generated by the detection unit that is the lowest. 5. The image forming apparatus according to claim 1, wherein a humidity measuring unit is provided in the vicinity of the accommodating unit, and the calculating unit determines the number of image-forming sheets according to the humidity measured by the humidity measuring unit. An image forming apparatus characterized in that means for adding a correction to an arithmetic operation is provided.