JP3661322B2 - Paper remaining amount detection method of image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for detecting a remaining amount of paper in an image forming apparatus such as a printer or a copying machine. The present invention relates to a method for detecting a remaining amount of paper in a paper feeding device that is sequentially conveyed to a printing unit.
[0002]
[Prior art]
For example, when performing double-sided copying with a copying machine, if the paper runs out in the middle, the work to be completed once must be performed twice, which takes a lot of labor and time. In such a case, it is particularly important to detect the remaining amount of paper before work. Conventionally, as one of the methods for detecting the remaining amount of paper, the elevator on which the paper is loaded is driven by a small DC motor, and the remaining time of the paper is detected by detecting the operation time and the rotation speed of the small DC motor. There is something. However, since the rotation speed of this small DC motor changes depending on the driving load, if the remaining amount of paper is detected simply by using the operation time or the number of rotations, the detection value varies depending on the driving load that differs depending on the paper size and quality. It is fluctuating and it is impossible to accurately detect the remaining amount of paper.
[0003]
In order to solve such a decrease in detection accuracy, for example, in the paper remaining amount display device disclosed in Japanese Utility Model Publication No. 62-121234, the number of pulses generated as the drive motor rotates is detected. The remaining amount of paper is detected based on the integrated value. Further, in the remaining sheet amount detecting device disclosed in Japanese Patent Application Laid-Open No. 58-22235, the distance from the sheet placement table lower limit position is detected, and the pulse signal of the pulse motor that drives the sheet placement table is detected. The remaining amount of paper is detected by subtracting this pulse signal from a predetermined set value. With such a pulse motor, there is no output fluctuation with respect to the driving load, and the remaining amount of paper can be detected with relatively high accuracy.
On the other hand, in the remaining paper amount detection device disclosed in Japanese Patent Laid-Open No. 6-191676, a small DC motor is used, and the rotation speed of the small DC motor is detected by, for example, an optical encoder, and a rotation created in advance. The remaining amount of paper is derived from the relationship data between the speed and the remaining amount of paper. According to this method, it is possible to detect the remaining amount of paper with relatively high accuracy even when a small DC motor that generates output fluctuations is used.
[0004]
[Problems to be solved by the invention]
However, in the method of detecting the remaining amount of paper using the number of pulses generated with the rotation of the drive motor described above, or the method of detecting the remaining amount of paper using the pulse signal from the pulse motor by driving the pulse motor. In addition, the configuration is complicated, and an expensive pulse motor is required, which causes a problem of an increase in cost. In addition, in the method of using a small DC motor and detecting the rotation speed with an optical encoder, although an inexpensive small DC motor can be used, an expensive encoder must be used to detect the rotation speed. It had the problem of increasing costs.
The present invention has been made in view of the above circumstances, and provides a sheet remaining amount detection method for an image forming apparatus that can detect the remaining sheet amount with high accuracy without using an expensive pulse motor or encoder. There is.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, a sheet remaining amount detection method for an image forming apparatus according to the present invention is a sheet remaining amount detection method for an image forming apparatus that detects the remaining amount of sheets loaded on a lift. The sheet information of the sheet is detected, the drive motor is operated to raise the elevator until the sheet reaches a position where paper can be fed, and after the supply of the sheet onto the elevator, the drive motor The time required for the operation of the drive motor from the start of the operation to the completion of the lifting of the lifting platform is obtained, the unit time required to lift up a certain amount of paper is stored in advance for each paper information, The unit time corresponding to the paper information detection value and the operation time are used to calculate the remaining amount of paper stacked on the elevator, and the paper information is paper size information, paper quality information, and environmental information. It is characterized by Than it is.
[0006]
In this paper remaining amount detection method of the image forming apparatus, a unit time required to lift up a certain amount of paper is obtained in advance for each piece of paper information, and the paper information of the actual paper loaded on the lifting platform is detected. Thus, the unit time specific to the stacked paper is obtained, and based on this unit time, the actually detected drive motor operating time is used, so that errors caused by the difference in paper conditions can be eliminated, and the drive load Even if a small DC motor whose rotational speed changes due to the above is used, it is possible to detect the remaining amount of paper with high accuracy without providing a special device.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a preferred embodiment of a paper remaining amount detection method for an image forming apparatus according to the present invention will be described in detail with reference to the drawings.
FIG. 1 is a flowchart showing a procedure of a remaining paper amount detection method according to the present invention, FIG. 2 is a flowchart showing a procedure in a paper feed state of the remaining paper amount detection method according to the present invention, and FIG. FIG. 4 is a schematic configuration diagram of an apparatus for carrying out the remaining paper amount detection method according to the present invention.
The remaining paper amount detection method according to the present invention performs detection separately when the image forming apparatus is in the following three states.
The first state is when the copier is turned on at the start of work and the copier enters the operating state.
The second state is when the elevator (paper feed tray) 1 is once pulled out and the paper feed tray 1 is mounted again after the paper 3 is replenished or replaced in the copying machine in operation.
The third state is when the operating copying machine is in the paper feeding state for copying.
[0008]
First, the remaining paper amount detection procedure in the first state will be described with reference to FIG.
First, when the power of the copying machine is turned on at the start of business (st1), it is confirmed whether the level sensor 5 of the paper feed tray 1 is on or off (st3). If the level sensor 5 is in the ON state, it is determined that the paper 3 has not been replenished to the paper feed tray 1 after the end of the previous day when the power of the copier is turned off. The remaining amount value is set (st5) and displayed on the display unit of the copying machine (st13).
[0009]
On the other hand, when the level sensor 5 is OFF, it is determined that the paper 3 is supplied to the paper feed tray 1 after the end of the day before the power is turned off, and the paper information and environmental information in the paper feed tray 1 are obtained. Detect (st7).
[0010]
This paper information is a factor that fluctuates the output of the drive motor (lift motor) 7, and is, for example, paper size information such as B5, A4, and A3, and paper quality information such as plain paper and OHP paper. The environmental information is information such as humidity related to the increase or decrease of the paper weight. The paper size information can be obtained using a known technology such as a paper size detection sensor, the paper quality information can be obtained using a known technology such as an OHP identification sensor or a paper quality selection switch, and the environmental information can be obtained using a known technology such as a humidity sensor or a paper moisture sensor. it can.
[0011]
Next, the lift motor 7 is driven (st9), and the paper 3 is lifted up to a position where the level sensor 5 is turned on. At this time, the time required for lift-up is stored in the storage calculation means 9.
Next, the remaining amount of paper at the end of the previous day stored in the storage calculation means 9 is reset, and necessary information among the paper information and environmental information detected in st7 and the time required for lift-up are set in advance. Then, the calculation is performed by inputting the following equation 1 (st11).
[0012]
T _Z = (T ₀ −T _L ) / T _T ...... Equation 1
However, T _Z : paper remaining time equivalent value (paper remaining value)
T ₀ : Time required for lift-up when paper is 0 T _L : Actual lift-up time required T _T : Unit time required for lifting a certain amount of paper.
[0013]
In Equation 1, (T ₀ −T _L ) indicates the time required to lift up the sheet 3 currently remaining in the sheet feed tray 1. Therefore, the remaining sheet value (T _Z ) can be obtained by dividing (T ₀ −T _L ) by the unit time (T _T ) required to lift up a certain amount of sheets.
Further, the values of T ₀ and T _T differ depending on the above-mentioned paper information and environment information, and values corresponding to the paper information and environment information detected in st7 are respectively examined in advance and stored in the storage calculation means 9. It is obtained from the paper size table 11, the paper quality table 13, and the water content table 15 shown in FIG.
[0014]
Therefore, the storage calculation means 9 multiplies the remaining sheet value (T _Z ) obtained by the calculation formula 1 and a certain amount (for example, 10 sheets of A4) of the sheet 3 that can be lifted up in unit time (T _T ). As a result, the remaining amount of paper is calculated. This is reset as a new remaining amount of paper and displayed on the display unit of the copying machine (st13).
[0015]
The remaining amount display can be displayed in stages.
For example, if the maximum loading capacity is N,
(Remaining paper value) (Display example)
When 0, NO PAPER
From 1 (T _T lift-up amount) to N / 4 LOW PAPER
When N / 4 to 2N / 4, 1/2 PAPER
3/4 PAPER when 2N / 4-3N / 4
When 3N / 4 ~ N FULL PAPER
It is like this.
[0016]
In addition, the unit time (T _T ) differs depending on the remaining amount of the paper 3 in addition to the above-described paper information and environment information. Therefore, by determining the remaining amount of paper in stages and obtaining different unit times according to this stage, it is possible to obtain a more accurate unit time (T _TH ). The unit time (T _TH ) checked according to the remaining amount is stored as the remaining amount information in the remaining sheet table 17 shown in FIG. The remaining amount detection can be made with higher accuracy.
[0017]
Next, the remaining paper amount detection procedure in the second state will be described.
As described above, the second state is a state when the sheet feeding tray 1 is remounted in the copying machine in operation. Therefore, in the first state, the level sensor 5 is OFF. It becomes the same state. Therefore, the remaining amount of the sheet 3 can be detected and displayed by performing the same procedure as that after st7 in FIG.
[0018]
Next, the remaining paper amount detection procedure in the third state will be described with reference to FIG.
In this state, as described above, the copying machine is in a paper feeding state, and the paper 3 is supplied from the paper feeding tray 1 to the image forming unit (st15).
When it is confirmed that the level sensor 5 of the paper feed tray 1 has been turned off by feeding the paper 3 (st17), the lift motor 7 is driven for a unit time (T _T ) to lift up the paper 3 ( st19).
[0019]
At this time, the paper 3 is shifted up by a unit time (T _T ) regardless of whether the level sensor 5 is turned on. As a result, time errors due to heavy paper, light paper, and the like can be eliminated.
Accordingly, since it is the only lifted up unit time (T _T), by subtracting 1 from the remaining paper value (T _Z) (st21), a certain amount of paper 3 can be lifted up to the unit time (T _T) The remaining amount of paper after the unit time (T _T ) is lifted up is calculated. That is, the current remaining amount of paper is detected by subtracting a certain amount of the paper 3 lifted up in unit time (T _T ) from the paper 3 loaded on the paper feed tray 1 (st23). This is reset as a new remaining amount of paper and displayed on the display unit of the copying machine (st25).
[0020]
Note that the paper information (paper size information, paper quality information), environment information, and remaining paper amount information described in the above embodiment can be calculated using all information or desired information. Therefore, if only the paper size information is used, only the paper size information table is stored, only the paper size information is detected, and T ₀ and T _T corresponding to the detected values are obtained from the paper size information table. Perform the operation.
[0021]
When paper size information and paper quality information are used, the paper size information table and paper quality information table are stored, the paper size information and paper quality information are detected, and the respective detections are made from the paper size information table and paper quality information table. Calculation is performed by obtaining T ₀ and T _T satisfying the values. At this time, T ₀ and T _T are stored as a sheet size information table and a sheet quality information table as hierarchical (see FIG. 3) or matrix information, for example, the sheet 3 is A4 size and has a sheet quality. T ₀ , T _T (for example, T ₀ = 4, T _T = 0.2) can be specified.
[0022]
【The invention's effect】
As described above in detail, according to the sheet remaining amount detection method of the image forming apparatus according to the present invention, it is necessary to detect the sheet information, obtain the operating time of the drive motor, and lift up a certain amount of sheets. Since the unit time is stored and the remaining amount of paper is detected using the unit time and operation time corresponding to the paper information detection value, the shortcoming of the small DC motor whose output changes depending on the driving load is compensated. The remaining amount of paper can be detected with high accuracy using an inexpensive small DC motor without using an expensive pulse motor or encoder. Further, since it can be implemented only by changing the software without adding a new member, it is possible to easily add a remaining sheet detection function to an existing apparatus.
[Brief description of the drawings]
FIG. 1 is a flowchart showing a procedure of a remaining paper amount detection method according to the present invention.
FIG. 2 is a flowchart showing a procedure in a paper feed state of a remaining paper amount detection method according to the present invention.
FIG. 3 is an explanatory diagram of an information table.
FIG. 4 is a schematic configuration diagram of an apparatus for performing a remaining paper amount detection method according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Paper feed tray (elevating base) 3 Paper 7 Drive motor 9 Memory | storage calculation means

Claims (2)

In the method for detecting the remaining amount of paper in the image forming apparatus for detecting the remaining amount of paper loaded on the elevator,
Detecting paper information of the paper loaded on the lifting platform;
Operate the drive motor to raise the elevator until the paper reaches a position where paper can be fed,
After replenishing the paper on the lift, the time required for the operation of the drive motor from the start of operation of the drive motor to the completion of the lift of the lift is obtained.
A unit time required to lift up a certain amount of paper is stored in advance for each piece of paper information,
Using the unit time corresponding to the paper information detection value and the operation time, to calculate the remaining amount of paper stacked on the lifting platform ;
The paper remaining amount detection method for an image forming apparatus, wherein the paper information is paper size information, paper quality information, and environmental information . When a level sensor that detects that the paper has reached a position where paper can be fed turns from ON to OFF due to paper feeding to the image forming unit, the drive motor is operated for the unit time,
A certain amount of paper lifted up in the unit time is subtracted from the already calculated remaining paper amount and reset as a new remaining paper amount.
The method for detecting a remaining amount of paper in an image forming apparatus according to claim 1.

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