JPH06100200A - Device and method for detecting residual amount of recording paper of image forming device - Google Patents

Abstract

PURPOSE:To accurately detect the residual amount of the recording paper on a recording paper elevating table even when the thickness of the recording paper to be loaded is different from that of the paper loaded in the previous or further previous operation. CONSTITUTION:When the copying is started, the loaded recording paper is fed to the body of an image forming device successively from the uppermost part, and an elevating table 14 is gradually elevated. The number of the recording paper to be fed is counted by a fed recording paper counter 39, and the counted value is received by a central processing unit 26. At the same time, the central processing unit 26 receives the pulse number (the distance information D4) equivalent to the elevation of the elevating table 14 from a counter 38, and the distance information D4 and the actual pulse number (the distance information Da) per paper sheet to be fed are computed. Then, the distance information D5 (the residual amount of the paper to be fed) which is obtained by subtracting the distance information D4 from the distance information D3 is divided by the distance information Da and a new information Db (the residual amount of the recording paper on the elevating table 14) is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording sheet remaining amount detecting apparatus and method for an image forming apparatus, and more particularly, to stack recording sheets on an elevating table of an elevating device and raise the elevating table to store storage sheets. The present invention relates to an apparatus and method for detecting the remaining amount of recording paper in an elevating device that sequentially supplies the main body of the image forming apparatus. Examples of the image forming apparatus include an electrostatic copying machine and a laser printer for an electronic computer.

[0002]

2. Description of the Related Art A method using a variable resistor (potentiometer) has been proposed as a method for detecting the remaining amount of recording paper loaded on an elevator. That is, the movable terminal (arm) of the variable resistor is interlocked with the vertical movement of the lift table, the electric resistance value between the movable terminal and the reference terminal is obtained, and the "relationship between the position of the lift table and the resistance value" is calculated in advance. Is used to identify the position of the lifting table and to detect the remaining amount of recording paper.

[0003]

However, with this conventional method, the remaining amount of the recording paper cannot be accurately obtained due to the variation in the accuracy of the resistance value. On the other hand, if the accuracy of the resistance value is increased, the manufacturing cost of the device increases, and there is a problem that adjustment at the time of shipping and maintenance after shipping take time.
In addition, when recording paper with a thickness other than the specified thickness is loaded,
There is also a problem that the remaining amount of recording paper cannot be detected accurately.

[0004]

A first device according to the present invention relates to a device for detecting the remaining amount of recording paper loaded on an elevating table of an elevating device of an image forming apparatus. A motor for determining the position of the lift table, a rotation speed detection means for detecting the rotation speed of the motor, a paper feed number counting means for counting the number of recording sheets fed from the lift table, and the rotation speed detection means. Based on the information obtained from the means and the number of fed sheets counting means, the moving distance information of the lifting table and the position information of the lifting table per one recording sheet are obtained, and the remaining recording sheets loaded on the lifting table are obtained. A recording sheet remaining amount detecting device of an image forming apparatus having a means for detecting the amount.

A second device according to the present invention relates to a device for detecting the remaining amount of recording paper loaded on an elevating table of an elevating device of an image forming apparatus. The elevating table is moved up and down to adjust the position of the elevating table. Based on the information obtained from the pulse motor for determining, the sheet feed number counting means for counting the number of recording sheets fed from the elevating table, and the information obtained from the pulse motor and the sheet feed number counting means, A recording sheet remaining amount detecting device of an image forming apparatus, comprising: a moving distance information of the lifting platform and a position information of the lifting platform and detecting a remaining amount of the recording sheets loaded on the lifting platform. .

A method according to the present invention relates to a method of detecting the remaining amount of recording paper loaded on an elevating table of an elevating device of an image forming apparatus, which is a first method for indicating a distance from a lower limit position to an upper position of the elevating table. Distance information is obtained in advance and stored, and (a) the elevating table is lowered to the lower limit position, and the elevating table is raised until the uppermost recording sheet of the stacked recording sheets reaches the sheet feeding position, and the elevating table is moved up and down. The second distance information corresponding to the ascending distance of the table is obtained, (b) the third distance information indicating the difference between the first and second distance information is obtained, and (c) the recording sheet fed from the elevating device. The number of sheets is counted, and (d) the fourth distance information corresponding to the ascending distance of the lift table per recording sheet is obtained from the obtained number of recording sheets and the second distance information,
(E) A method for detecting the remaining amount of recording paper in an image forming apparatus, which detects the remaining amount of recording paper by using the third and fourth distance information.

[0007]

Embodiments of the present invention will be described below with reference to the accompanying FIGS.

1 and 2 are views for explaining an elevating device of an image forming apparatus directly related to the implementation of the present invention, and FIG.
Is a block diagram showing a hardware configuration for carrying out the present invention, and FIGS. 4 to 7 are operation diagrams of an elevating device for explaining the present embodiment in detail.

As shown in FIG. 1, the elevating device 10 has an elevating table 14 for loading and elevating a plurality of recording sheets 12. The motor 16 that is the power source of the lifting platform 14 uses the belt 1
The elevating table 14 is moved up or down via 8 and the wire 20.

When the motor 16 rotates in the direction to raise the lifting table 14, the wire 20 is wound around the wire winding portion 22, and conversely, when the motor 16 rotates in the direction to lower the lifting table 14, the wire 20 moves. Wire winding part 22
Extends downward from. These mechanisms are publicly known and have no direct relation to the present invention, and therefore a detailed description thereof will be omitted.

In FIG. 1, the lower limit position of the lift 14 (shown by the broken line 15) is determined by the lift lower limit position detection switch 24. That is, the elevator 14 descends and the switch 2
When 4 is closed (see FIG. 4), as shown in FIG. 3, the central processing unit (CPU) 26 stops the rotation of the motor 16 via the motor control unit 28 in response to the signal from the switch 24.

The uppermost recording sheet detection switch 30 is a switch for detecting the recording sheet located at the uppermost portion of the stacked recording sheets 12 by the lever 32. That is, when the rising recording sheet comes into contact with the lower portion of the lever 32, as shown in FIG.
Is lifted from the position shown by the solid line to the position shown by the dotted line (position in FIG. 1), and the switch 30 is closed. When the switch 30 is closed, the central processing unit 26 stops the rotation of the motor 16 via the motor control unit 28 and stops the lifting of the elevating table 14.

FIG. 2 is a diagram for explaining the operation of the protection switch 34 for stopping the lifting of the elevating table 14 when there is no recording paper on the elevating table 14. If even one sheet of recording paper is present on the lift table 14, the above-described switch 30 is activated to prevent the lift table 14 from rising. However, when there is no recording paper on the lift table 14, the main body of the switch 30 and the lever 32 pass through an opening (not shown) provided in the lift table 14, and the lift table 14 continues to rise. However, the lift 14
When the end of the switch closes the switch 34 as shown in FIG. 2, the central processing unit 26 detects that the protection switch 34 is closed and stops the rotation of the motor 16 via the motor control unit 28 ( See FIG. 2).

In FIGS. 1, 2 and 3, the encoder 36 outputs a pulse signal according to the rotation speed of the motor 16. That is, by counting the number of pulses from the encoder 36 with the counter 38, the distance information (the number of pulses) corresponding to the ascending distance of the lift 14 can be measured.

As shown in FIG. 1, when the elevator 14 is raised and the uppermost recording sheet loaded is closed with the switch 30 closed, the loaded recording sheets are sequentially transferred from the uppermost recording sheet. It is ready to be fed to the main body (not shown). It should be noted that the image forming apparatus main body and the sheet feeding device may be publicly known ones, and are not shown.

The number of recording sheets supplied to the main body of the image forming apparatus from the state of FIG. 1 is counted by a fed recording sheet counter 39 (only blocks are shown in FIG. 3).

As shown in FIG. 3, the central processing unit 26 is
It has a storage unit 40, and stores various distance information of the elevator 14 to be described later, calculation results, and the like. Further, the detected remaining amount of recording paper is displayed on the display unit 42 shown as a block in FIG.

As will be described later, the elevating table 14 descends to the lower limit position 15 when the door (not shown) of the elevating device is opened, and rises until the switch 30 (or switch 34) is closed when the door is closed. . The central processing unit 26 controls the descending / ascending of the above-described elevator base by a signal from the elevator device door opening / closing switch 44 (FIG. 3).

Embodiments of the present invention will be described in more detail with reference to FIGS. 4 to 7, the same parts as those in FIGS. 1 and 2 are designated by the same reference numerals.

First, the distance information (the number of pulses) from the lower limit position to the upper limit position of the lift 14 is obtained. In fact, Figure 4
As shown in (1), one sheet of recording paper 12 'is placed on the elevator 14 and the motor 16 is rotated to lower the elevator 14 to the lower limit position (that is, the lower limit position switch 24 is closed).
The control of the motor 16 is performed by the central processing unit 26 (FIG. 3) and the motor control unit 28. However, in order to avoid complication, the control of the motor itself may not be touched.

The elevating table 14 is raised from the position shown in FIG. 4, and the output pulse from the encoder 36 is counted by the counter 38. The elevating table 14 rises and the recording paper 1
When 2 ′ closes the switch 30 (FIG. 5), the central processing unit 26 stops the rotation of the motor 16 and fetches the count value of the counter 38. That is, the distance information (pulse number) D1 from the lower limit position to the upper limit position of the lift 14 is obtained. Since the number of output pulses of the encoder 36 per one rotation of the motor 16 and the moving distance of the lifting table 14 can be known in advance, it is necessary from the distance information D1 from the lower limit position to the upper limit position of the lifting table 14. If so, the actual distance can be calculated. The distance information D1 is stored in the storage unit 40 of the central processing unit 26.
Memorized in.

The distance information from the lower limit position to the upper limit position of the lift 14 is obtained in advance by the device manufacturer and stored in the storage unit 40.
It is convenient to remember in. However, the distance information may be obtained after the apparatus is installed, and if adjustment is required during maintenance and inspection of the apparatus, the distance information is obtained again and stored in the storage unit 40.

When the door of the elevating device is opened to load the recording sheets, the elevating table 14 descends to the lower limit position as described above. After loading the recording paper on the lift table 14, closing the door of the lifting device raises the lift table 14, the top recording paper closes the top recording paper detection switch 30, and the lift table 14 stops rising. The state shown in FIG. 6 is obtained.

When the elevating table 14 moves up to the position shown in FIG. 6, the central processing unit 26 receives the count value from the counter 38 and stores it in the storage section 40 as distance information (pulse number) D2. Further, the central processing unit 26 uses the distance information D1 and D1.
2, the distance information D3 from the position of the lifting platform 14 to the upper limit position in FIG. 6 is obtained, and is similarly stored in the storage unit 40.

Next, when copying is started, the stacked recording sheets are sequentially fed from the top to the main body of the image forming apparatus,
The lift 14 gradually rises. FIG. 7 shows a state in which the elevating table 14 is raised by feeding the recording paper. The number of fed recording sheets is counted by the fed recording sheet counter 39 shown in FIG. 3, and the counted value is taken into the central processing unit 26.
At the same time, the central processing unit 26 receives from the counter 38 the number of pulses (distance information D4) corresponding to the amount of rise of the lifting table 14.

The central processing unit 26 calculates the number of pulses per sheet fed (the distance information Da) from the distance information D4 and the actual number of fed sheets. Next, the distance information D5 (distance information corresponding to the remaining paper amount) obtained by subtracting the distance information D4 from the distance information D3 is divided by the distance information Da to obtain new information Db. The information Db represents the number of recording sheets remaining on the lift table 14.

The number of recording sheets Db thus obtained
Is sent to and displayed on the display unit of FIG.

In the above embodiment, the encoder 36 was connected to the motor 16 to obtain the number of pulses corresponding to the rotation of the motor, but the motor 16 and the encoder 36 may be replaced by a pulse motor.

Further, the counter 38 is provided in the central processing unit 26.
It may be provided inside.

[0030]

As described above, according to the present invention, the number of recording sheets actually fed is detected, and the remaining amount of recording sheets is measured according to the actual thickness of the recording sheets. That is, the present invention can detect the remaining amount of recording paper extremely accurately even when the type (thickness) of recording paper loaded is different from the previous one or the previous one. By knowing exactly the remaining amount of recording paper,
Various effects such as accurate prediction of shortage of recording paper can be obtained.

[Brief description of drawings]

FIG. 1 is a diagram for explaining an elevating device of an image forming apparatus directly related to the implementation of the present invention.

FIG. 2 is a diagram for explaining an elevating device of an image forming apparatus directly related to the implementation of the present invention.

FIG. 3 is a block diagram showing a hardware configuration for implementing the present invention.

FIG. 4 is an operation diagram of the lifting device for explaining the embodiment of the present invention in detail.

FIG. 5 is an operation diagram of the lifting device for explaining the embodiment of the present invention in detail.

FIG. 6 is an operation diagram of a lifting device for explaining an embodiment of the present invention in detail.

FIG. 7 is an operation diagram of the lifting device for explaining the embodiment of the present invention in detail.

[Explanation of symbols]

 10 Elevating Device of Image Forming Apparatus 14 Elevating Platform 16 Motor 24 Elevating Platform Lower Limit Position Detection Switch 26 Central Processing Unit 30 Uppermost Recording Paper Detection Switch 36 Encoder 38 Counter D1 to D5 Position Information (Pulse Number)

Claims (4)

[Claims] 1. An apparatus for detecting the remaining amount of recording paper loaded on an elevator of an elevator of an image forming apparatus, comprising: a motor for moving the elevator up and down to determine the position of the elevator; and rotation of the motor. A rotation number detecting means for detecting the number of sheets, a sheet feed number counting means for counting the number of recording sheets fed from the elevating table, based on information obtained from the rotation number detecting means and the sheet feed number counting means A recording sheet of an image forming apparatus having a means for obtaining the moving distance information of the lifting table and the position information of the lifting table per recording sheet and detecting the remaining amount of the recording sheet loaded on the lifting table. Remaining amount detection device. 2. An apparatus for detecting the remaining amount of recording paper loaded on an elevator of an elevator of an image forming apparatus, comprising: a pulse motor for moving the elevator up and down to determine the position of the elevator; Sheet feeding number counting means for counting the number of recording sheets fed from, and moving distance information of the lift table per recording sheet based on information obtained from the pulse motor and the feeding sheet number counting means. A recording paper remaining amount detecting device of an image forming apparatus, comprising: means for obtaining position information of the elevator and detecting the remaining amount of recording paper loaded on the elevator. 3. A method for detecting the remaining amount of recording paper loaded on an elevator of an elevator of an image forming apparatus, wherein first distance information representing a distance from a lower limit position of the elevator to an upper limit position is obtained in advance. (A) lowering the lift table to the lower limit position, raising the lift table until the uppermost recording sheet of the stacked recording sheets reaches the feedable position, and increasing the lift distance of the lift table. Obtaining corresponding second distance information, (b) obtaining third distance information representing the difference between the first and second distance information, (c) counting the number of recording sheets fed from the elevating device, (D) The fourth distance information corresponding to the ascending distance of the lift table per recording sheet is obtained from the obtained number of recording sheets and the second distance information, and (e) the third and fourth distances. Recording paper of image forming apparatus for detecting remaining amount of recording paper using information The amount detection method. 4. The recording paper remaining amount detecting method according to claim 3, wherein the first to fourth distance information is the number of electric pulses corresponding to the ascending distance of the elevator.