JP2972690B2 - Paper remaining amount detecting apparatus and method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for detecting the remaining amount of printing or recording paper, and more particularly, to loading a paper on a lifting platform of a lifting device, and raising the lifting platform to form a sheet of an image forming apparatus. The present invention relates to a method and an apparatus for detecting the remaining amount of paper in an elevating device to be supplied to the inside.

[0002]

2. Description of the Related Art As a conventional sheet remaining amount detecting device of this type, for example, an apparatus described in Japanese Patent Application Laid-Open No. 6-100200 detects the uppermost portion of sheets loaded on an elevator and simultaneously raises or lowers the elevator. The pulse motor drive was controlled to stop instantaneously. More specifically, the above-mentioned publication discloses a motor that moves the elevating platform up and down to determine the position of the elevating platform, rotation speed detecting means for detecting the number of rotations of the motor, and the number of recording sheets fed from the elevating platform. Sheet number counting means for counting the number of rotations, and the moving distance information and the position information of the lifting table per sheet of recording paper based on information obtained from the rotation number detecting means and the sheet number detecting means, There has been proposed a configuration including means for detecting the remaining amount of recording paper loaded on a lifting platform.

[0003]

However, it is practically impossible to stop the pulse motor instantaneously.
Since there is a slight overrun, the detection of the remaining amount of paper includes the number of pulses corresponding to the overrun.

In addition, since the pulse motor is frequently driven in accordance with the sheet feeding operation to elevate the elevator, the operating conditions are continuous, the load is large, the power consumption is increased, and the performance is high and expensive. There was a problem that one had to select one.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made in view of the above problems, and has as its object to stop the top of the sheet at a desired position and accurately determine the number of pulse motor pulses until the top of the sheet is detected. It is an object of the present invention to provide a method and an apparatus for detecting the remaining amount of paper, which enable highly accurate detection of the remaining amount of paper by enabling counting.

[0006]

In order to achieve the above-mentioned object, a sheet remaining amount detecting device according to the present invention drives a pulse motor until an uppermost portion of a sheet loaded on an elevator moves from an initial state to a sheet feeding lower limit position. After the paper detecting means detects that the uppermost sheet of paper has passed the lower limit of the paper feeding, the driving of the pulse motor is controlled to move the uppermost sheet of paper until the uppermost position of the paper is reached. The paper is fed up to a predetermined distance and stopped, and the paper is fed to the elevator.
The number of stacked sheets is reduced, and the top of the sheets is
The paper detecting means detects that the paper has been lowered to the lower limit position.
When the pulse motor corresponds to the predetermined distance.
Determine the number of pulses per sheet from the number of pulses and the number of sheets fed.
Calculated and based on this, the current
Calculate the remaining amount of paper .

In the present invention, the pulse motor is driven up until the uppermost portion of the sheets stacked on the lifting platform reaches the lower limit of the sheet feeding, and the uppermost portion of the sheet passes the lower limit of the sheet feeding from the initial state. The pulse number of the pulse motor when the sheet detecting means detects that the sheet has been detected is set to P2, and further, the drive of the pulse motor is controlled to move the uppermost portion of the sheet to a sheet feeding upper limit position by a predetermined distance. That is, the number of pulses is increased by the drive amount of P3 and stopped .
The difference P4 between the pulse number P1 and the pulse number P2 from when the sheet is not loaded on the elevator and rises from the initial state until the sheet detecting means detects the sheet mounting surface of the elevator is calculated by the arithmetic means. Every time the sheet is fed and the number of sheets stacked on the elevating table decreases, and when the sheet detecting means detects that the uppermost part of the sheet has dropped to the sheet feeding control position, the sheet detecting means corresponds to the predetermined distance. The number of pulses Pa per sheet is calculated by dividing the number of pulses P3 of the pulse motor by the number of sheets N fed by the calculating means. By dividing by the number Pa of pulses per sheet, the remaining number T of sheets stacked on the elevator is obtained.

[0008]

Embodiments of the present invention will be described below. In a preferred embodiment, the paper remaining amount detecting device according to the present invention comprises: a lifting platform (2 in FIG. 1) for loading and lifting paper; a pulse motor (3 in FIG. 1) for driving the lifting platform; A sheet detecting means (7 in FIG. 1) for detecting that the uppermost portion of the sheets stacked on the lifting platform has reached the sheet feeding position. The elevating platform is further raised by a predetermined amount after the upper part is detected by the paper detecting means, and the pulse motor is stopped while decelerating during the ascent. Therefore, according to the embodiment of the present invention, the top of the sheet can be stopped at a desired position, and the number of pulse motor pulses up to the detection of the top of the sheet can be accurately counted. It is.

More specifically, in the embodiment of the present invention, no paper is loaded on the lift table, and the lift table drives the pulse motor from a predetermined reference position to raise the table. The pulse counting means (4 in FIG. 1) counts the number of pulses (P1) of the pulse motor up to the position where the sheet detecting surface (7 in FIG. 1) detects the sheet loading surface of the elevating platform, and stores the pulse as an initial value. It is stored in advance in the means (5 in FIG. 2). Next, with the sheets loaded on the elevator, the elevator is driven by the pulse motor to raise the elevator from the elevation reference position to a position where the uppermost part of the paper is detected by the paper detection means (feed lower limit position S1). Further, the pulse motor is driven by a predetermined number of pulses (P3) to be raised until the paper feed upper limit position (S2) is reached. At this time, the lifting platform is moved from the raised reference position to the paper detection means (7 in FIG. 1). The number of pulses (P2) until turning on is counted, and a value (P4 = P2-P1) subtracted from the initial number of pulses (P1) stored in the pulse storage means is calculated by the calculation means (11 in FIG. 2). Ask for it.

When the sheet detecting means (7 in FIG. 1) is turned off, that is, when the sheet detecting means (7 in FIG. 1) is turned off, ie, from the upper limit position (S2) to the lower limit position (S1). The number of pulses (Pa) per sheet is obtained by dividing the number of pulses P3 corresponding to the calculated distance by the number of sheets N fed by the calculating means (11 in FIG. 2).
By dividing the previously obtained pulse number P4 by the number of pulses per sheet (Pa), the remaining number of sheets (T) to be stacked on the elevator is obtained.

According to the embodiment of the present invention, the pulse motor needs only to be raised by a predetermined amount when the uppermost portion of the sheet reaches the sheet feeding lower limit position from the sheet feeding upper limit position in the sheet feeding operation. However, the load is light because of the intermittent operation, and an inexpensive motor can be used.

It is preferable that the value obtained by converting the thickness of one sheet into the number of pulses: Pd be S times (S ≧ 1) the pulse motor driving pulse width: Pb .

[0013]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of the present invention;

FIG. 1 is a diagram schematically showing the configuration of one embodiment of the present invention. Referring to FIG. 1, an apparatus for detecting the amount of remaining paper according to an embodiment of the present invention includes a paper feed cassette 1, an elevator 2 rotatably supported in the paper cassette 1, and mounting a paper. A pulse motor 3 serving as a driving source to be raised, a pulse counting unit 4 for counting the number of pulses of the pulse motor 3, a pulse storage unit 5 for storing the number of pulses counted by the pulse counting unit 4 (see FIG. 2), A lift mechanism 6 for transmitting the drive from the pulse motor 4 to the lift 2 to lift it, sheet detecting means 7 for detecting that the uppermost portion of the sheets stacked on the lift 2 has reached the sheet feeding position, and a lift 2, a paper feed roller 8 for feeding out the paper stacked on the paper feeder 2, a paper feed counting means 9 for measuring the number of paper feeds fed by the paper feed roller 8, and a paper feed count for storing the number of paper feeds counted by the paper feed counting means 9. Paper storage means 10 (FIG. 2) And irradiation), a calculation unit 11 for calculating the number of pulses and remaining paper sheets per one sheet from the information stored in the paper feed storage means 10 and pulse storage unit 5 (see FIG. 2), a.

[0015] Here, the driving pulse width of the pulse motor 3 is smaller well, specifically, the value obtained by converting the thickness of one sheet of paper to a pulse number: P d is the pulse motor drive pulse width: Pb of S It is desirable to set it so as to be twice (S ≧ 1).

FIG. 2 is a lock diagram showing a configuration related to the arithmetic unit in this embodiment.

As described above, based on the information from the pulse storage means 5 for storing the counted number of pulses and the paper supply storage means 10 for storing the counted number of fed sheets, the arithmetic unit 11 performs processing for each sheet of paper. Is calculated, and the remaining number of sheets T is calculated.

Next, the operation of the present embodiment will be described with reference to FIGS. 3, 4, 5, and 6. FIG.

First, it is necessary to determine the amount of elevation of the elevator when there is no paper as an initial value in advance when manufacturing the apparatus or performing maintenance and inspection.

FIG. 3 is a diagram showing an initial state of the apparatus according to one embodiment of the present invention. No paper is set in the paper feed cassette 1, and the elevator 2 is at the elevation reference position P0.
The ascending reference position P0 may be a position where the elevating platform 2 naturally falls, or may be a position determined by detecting the height position of the elevating platform 2 with a sensor or the like.

From this state, as shown in FIG. 4, the pulse motor 3 is driven to gradually raise the lift table 2 via the lift mechanism 6, and the sheet stacking surface 2a of the lift table 2 is detected by the paper. The pulse counting means 4 counts the number of pulses P1 of the pulse motor 3 until the position S1 at which the means 7 is turned on, that is, until the detecting section 7a of the paper detecting means 7 changes to 7b, and stores the pulse as an initial value. It is stored in the means 5.

As shown in FIG. 1, when the sheet 20 is set on the elevator 2, the pulse motor 3 drives the elevator 2 to turn on the uppermost part 20a of the sheet from the elevation reference position P0. Yes (detection unit 7a changes to 7b)
The control is performed so as to rise to the position S1 and further increase therefrom by a predetermined number of pulses: P3.

Here, the number of pulses: P2 from when the lifting platform 2 is raised to the reference position P0 until the paper detecting means 7 is turned on is counted, and the initial number of pulses: P1 stored in the pulse storage means 5 is calculated. Subtracted value: P4 (P4 = P1-P2)
Is obtained by the arithmetic unit 11 in advance.

Generally, there is a range in which the sheet can be normally fed at the sheet feeding position, and the pressing force of the sheet feeding roller 8, the position of the conveying roller (not shown) downstream of the sheet feeding roller 8, and the sheet loaded on the elevating table 2. The range is determined by the angle of the sheet 20 in the state.

In the present embodiment, the lower limit position of the paper supply range is set as the detection position S1 of the paper detection means 7, and the upper limit position of the paper supply range is further raised by a predetermined amount P3 from the detection position S1 of the paper detection means 7. The position S2 was set.

However, in practice, the upper limit position S2 and the lower limit position S1 of the feedable range vary depending on the use environment, conditions, and the like. Therefore, in an actual design, the upper limit position S2 and the lower limit position S1 are larger than the feedable range. Should be set narrow.

The conventional paper remaining amount detecting device described in the above-mentioned Japanese Patent Application Laid-Open No. 6-100200 discloses an S-type detecting device for detecting the remaining amount of paper as shown in a time chart of FIG.
The pulse motor was driven to 1 and the value Pc was counted. However, it is practically impossible to stop the pulse motor instantaneously, and a slight overrun Pr occurs. That is, the counted pulse number P
Since c is equal to the number of driven pulses P2 and does not include the number Pr of pulses for the overrun, the counted number of pulses Pc does not match the positional relationship of the lift.

On the other hand, in the paper remaining amount detecting apparatus according to one embodiment of the present invention, as shown in a time chart of FIG.
Is driven at a constant high speed, and is controlled to stop at a desired position while gradually decreasing the speed when the predetermined amount: P3 increases.

Thus, the number of pulses to be counted Pc
Is the sum of the pulse number P2 up to the position S1 at which the sheet detection means 7 is turned on and the pulse number P3 of a predetermined amount set in advance, so that the counted pulse number Pc and the lift 2
Are exactly the same.

Next, as shown in FIG. 5, when there is a paper feed command from the host device or the like to the apparatus, the paper 20 is sequentially fed out from the upper surface by the paper feed roller 8. This paper feeding operation is a well-known technique, and a detailed description thereof will be omitted.

At the time of the sheet feeding operation, the number N of sheets fed is counted by the sheet feeding counting means 9 and the number is stored in the sheet feeding storage means 10.

The uppermost position of the sheet is sequentially lowered by the sheet feeding, and finally the sheet detecting means 7 is turned off. In other words, since the distance from the upper limit position S2 to the lower limit position S1 corresponds to the predetermined rising amount P3, the arithmetic unit 11 divides the predetermined rising amount P3 by the number N of fed sheets. The number Pa of pulses per sheet can be obtained.

Further, by dividing the number of pulses P4 previously determined by the arithmetic unit 11 by the number of pulses Pa per sheet, the remaining number of sheets 20 of the sheets 20 stacked on the lifting platform 2 (T (T = P4 / Pa) can be accurately obtained.

Thereafter, the lift 2 is raised again by the predetermined amount P3, and feeding is repeated. At this time, if necessary, the number of fed sheets N is counted and the
The calculation of the number Pa of pulses per sheet and the calculation of the remaining amount of paper T by the arithmetic unit 11 may be repeated.
Further, since the pulse motor 3 is intermittently driven as described above, a load on the motor 3 is small and an inexpensive motor can be selected.

Further, if the detected remaining paper amount T is appropriately displayed on a display section of the apparatus or a display section of a higher-level apparatus, the operator can be notified of an appropriate paper supply time.

FIG. 7 is a flowchart showing the operation of the above-described embodiment of the present invention.

Referring to FIG. 7, in the present embodiment,
The paper is set on the lift 2 (step 101), and the pulse motor 3 is rotated to drive the lift mechanism 6 (step 1).
02, 103), the number of pulses of the pulse motor 3 is counted by the pulse counting means 4 (step 106).
Is raised from the raising reference position, and the number of pulses of the pulse motor when the paper detecting means 7 detects that the uppermost portion 20a of the paper has passed the paper feeding lower limit position S1 (ON in step 105) is set to P2 (step 107).

Further, the paper feed lower limit position S1 is set to the uppermost sheet 2 of the paper.
After the passage of 0a, the pulse motor 3 is controlled to be decelerated to raise the uppermost portion of the sheet by a predetermined distance, that is, the pulse number P3 drive to the sheet feeding upper limit position S2 (step 109).

Also, the number of pulses P1 until the lifting platform is raised from the reference position and the paper detecting means detects the paper mounting surface of the lifting platform without loading paper on the lifting platform.
The difference P4 between P2 and P2 is calculated by an arithmetic unit (step 108).

In response to a paper feed command from the host device (step 110), paper is fed (step 111), the number of papers loaded on the elevator 2 is reduced, and the top of the paper is lowered to the paper feed control position S1. When the sheet detection means 7 detects that the sheet feeding has been completed (step 112), and the sheet feeding is not completed (NO branch of step 112), the sheet feeding operation is repeated. The number of pulses Pa per sheet of paper is calculated by dividing the number of pulses P3 of the pulse motor 3 by the number of fed sheets N (step 1).
14 to 116), and the arithmetic unit 11 divides the pulse number P4 determined previously by the pulse number Pa per sheet to obtain the remaining number T of sheets stacked on the elevator. It is determined (step 117).

[0041]

As described above, according to the present invention,
Since the uppermost sheet loaded on the ascending elevator is detected by the sheet detecting means, the sheet is further raised by a predetermined amount P3, and the pulse motor is decelerated and stopped at the rise of the predetermined amount P3. Thus, the number of pulse motor pulses P2 up to the detection of the uppermost portion of the sheet can be accurately measured, and the remaining amount of the sheet can be accurately detected.

Further, according to the present invention, the pulse motor needs only to be raised again by the predetermined amount P3 when the paper within the predetermined amount P3 reaches the paper feed lower limit position. Since a light and inexpensive motor can be used, there is an effect that the cost of the sheet remaining amount detecting device can be reduced.

[Brief description of the drawings]

FIG. 1 is a diagram schematically illustrating a configuration of an embodiment of the present invention, and is a diagram illustrating a state in which a sheet has reached a paper feed upper limit position.

FIG. 2 is a block diagram showing a configuration of one embodiment of the present invention.

FIG. 3 is a diagram schematically illustrating a configuration of an example of the present invention, and is a diagram illustrating an initial state.

FIG. 4 is a diagram schematically showing the configuration of one embodiment of the present invention, and is a diagram showing how initial values are detected.

FIG. 5 is a diagram schematically illustrating the configuration of an embodiment of the present invention, and is a diagram illustrating a state when a sheet reaches a sheet feeding lower limit position.

FIG. 6 is a diagram showing a time chart of the pulse motor of one embodiment of the present invention.

FIG. 7 is a flowchart showing a processing flow of an embodiment of the present invention.

FIG. 8 is a diagram showing a time chart of a conventional pulse motor.

[Description of Signs] 1 paper feed cassette 2 elevator 3 pulse motor 4 pulse counting means 5 pulse storage means 6 lift mechanism 7 paper detecting means 7a, 7b, 7c paper detecting means detecting section 8 paper feeding roller 9 paper feeding counting means 9a , 9b paper feed counting means detection section 10 paper feed storage means 11 arithmetic unit 20 paper 20a, 20b paper upper surface P0 lift base reference position P1 number of pulses until paper detection means ON without paper (initial value) P2 paper Number of pulses until the paper detecting means is turned on in the set state P3 Number of pulses of a predetermined amount P4 Number of pulses for remaining amount of paper Pa Number of pulses per sheet Pc Number of pulses to be counted Pr Number of pulses for pulse motor overrun S0 Initial position of paper detecting means detecting section S1 Paper detecting means detecting position (lower feed position) S2 Predetermined from paper detecting means detection The position where the amount has risen (upper limit position of paper feed)

Claims (6)

(57) [Claims] 1. A pulse motor is driven up from the initial state until the uppermost portion of the sheets stacked on the lifting platform reaches the lower limit position of the sheet feeding, and the uppermost portion of the sheet passes through the lower limit position of the sheet. After the detection by the detecting means, the drive of the pulse motor is controlled to raise and stop the uppermost part of the sheet by a predetermined distance until the sheet reaches the upper limit of the sheet feeding , and the sheet is fed and the The number of sheets loaded on the table
And the top of the paper is lowered to the paper feed lower limit position.
When the paper detecting means detects that
The number of pulses of the pulse motor corresponding to separation and the number of sheets fed
The number of pulses per sheet is calculated from
Remaining paper detection apparatus characterized that you calculate the current remaining sheets to be stacked on the elevator platform. 2. A pulse motor is driven up until the uppermost portion of the sheets stacked on the elevator reaches the lower limit of the sheet feeding, and it is determined that the uppermost portion of the sheet has passed the lower limit of the sheet feeding from the initial state. The pulse number of the pulse motor at the time of detection by the sheet detection means is set to P2, and further, the drive of the pulse motor is controlled so that the uppermost portion of the sheet is a predetermined distance to the upper limit of the sheet feeding, that is, The number of pulses P3 is increased by the drive amount and stopped, and the number of pulses P1 from the initial state in a state where sheets are not loaded on the elevator and rising from the initial state until the sheet detecting means detects the paper loading surface of the elevator is represented by The difference P4 from the P2 is calculated by the calculating means, and it is determined that the sheet is fed and the number of sheets stacked on the elevator is reduced, and that the top of the sheet is lowered to the sheet feeding lower limit position. When the sheet detecting means detects, the number P3 of pulses of the pulse motor corresponding to the predetermined distance is divided by the number N of fed sheets by the calculating means to calculate the number Pa of pulses per sheet. In the means, the remaining number T of sheets loaded on the elevator is obtained by dividing the number of pulses P4 previously obtained by the number of pulses Pa per sheet. The sheet remaining amount detecting device according to claim 1 . 3. A lifting platform for loading and raising and lowering sheets, a pulse motor for driving and controlling the vertical movement of the lifting platform, pulse counting means for counting the number of pulses of the pulse motor, and counting by the pulse counting means. Pulse storage means for storing the number of pulses obtained, sheet detection means for detecting that the uppermost part of the sheets stacked on the lifting platform has reached a sheet feeding position, and sheet feeding counting means for counting the number of sheets fed. Paper feed storage means for storing the number of paper feeds counted by the paper feed counting means; and the number of pulses per sheet and the number of remaining papers based on information stored in the paper feed storage means and the pulse storage means. Calculating means for calculating the height of the sheet loaded on the ascending and descending platform, and further elevating the ascending and descending platform by a predetermined amount after the sheet detecting means detects the uppermost portion of the sheets stacked thereon. While decelerating the Oite pulse motor is stopped, the paper remaining amount detection apparatus characterized by. 4. A sheet is not loaded on the elevator, and the elevator is driven by the pulse motor from a predetermined ascending reference position to raise the sheet, and the sheet loading surface of the elevator is detected. The number of pulses (P1) of the pulse motor up to the position detected by the means is counted by the pulse counting means and stored as an initial value in the pulse storage means in advance. By driving the pulse motor, the lifting platform raises the uppermost sheet from the reference position to the lower limit position (S1) where the uppermost sheet is detected by the sheet detecting means. ), The pulse motor is driven to move up to reach the upper-limit paper feed position (S2). At this time, the elevator is moved from the reference position to the uppermost position of the paper. Number of pulses until the output (P2) counts the number of pulses of the initial values stored in the pulse storage unit minus from (P1) (P4 = P2-P1)
Is calculated by the arithmetic means, and when the uppermost portion of the paper is sequentially lowered by the paper feeding and the paper detecting means detects that the paper lowers to the paper lower limit position, that is, when the paper is fed from the paper upper limit position (S2). The number of pulses P3 corresponding to the distance to the paper lower limit position (S1) is divided by the number N of fed sheets by the calculating means to obtain the number of pulses per sheet (Pa). The remaining number (T) of sheets loaded on the elevator is obtained by dividing the previously obtained number of pulses P4 by the number of pulses per sheet (Pa). The paper remaining amount detecting device according to claim 2 or 3, wherein: 5. The drive pulse width of the pulse motor is a value obtained by converting the thickness of one sheet of paper to a pulse number of said Parusumo
Motor drive S times the pulse width (S ≧ 1) and so as to set of <br/> is to have any one in the paper remaining amount detection apparatus according to claim 1 to 4, this and characteristics. 6. A pulse motor is driven up until the uppermost portion of the sheets stacked on the lifting platform reaches the lower limit of the sheet feeding position, and it is determined that the uppermost portion of the sheet has passed the lower limit position of the sheet feeding from the initial state. The pulse number of the pulse motor at the time of detection by the detection means is set to P2, and the pulse motor is further decelerated to drive the uppermost portion of the sheet to a paper feeding upper limit position by a predetermined distance, that is, the pulse number P3 drive The number of pulses P1 and P2 from the initial state in a state where sheets are not loaded on the lift table to the time when the sheet detecting means detects the sheet mounting surface of the lift table. The sheet detection means detects that the sheet has been fed and the number of sheets stacked on the elevator has decreased, and that the top of the sheet has dropped to the sheet feed control position. At this time, the pulse number Pa per sheet is calculated from the pulse number P3 of the pulse motor corresponding to the predetermined distance and the sheet number N, and the pulse number P4 obtained earlier is calculated as the pulse number per sheet. Several Pa
A remaining sheet number T of sheets stacked on the lift table by dividing the sheet number by the following formula.