JPS63295372A - Paper feed device for recording apparatus - Google Patents

Abstract

PURPOSE:To make it possible to take an appropriate measure before a serious trouble occurs by providing such an arrangement that occurrence of an abnormality is indicated if no predetermined electrical signal is issued until a predetermined time elapses after initiation of the drive of an elevating mechanism. CONSTITUTION:The time of lapse is measured after initiation of the drive of an elevating mechanism 66. If an elevation detecting means 65a for detecting the operation of the elevating mechanism 66 does not issue a predetermined electrical signal until a predetermined time elapses after initiation of the drive of the elevating mechanism 66, an alarm means is energized to inform occurrence of an abnormality. That is, if no actual operation is detected even though a time exceeding the predetermined time elapses although the drive is initiated, it is regarded as occurrence of a certain abnormality. Accordingly, it is possible to promptly detect an abnormality in the elevating mechanism 66, and the alarm thereof may be at once issued, thereby it is possible to take a suitable measure before occurrence of a serious trouble.

Description

Detailed Description of the Invention [Field of the Invention] The present invention relates to a paper feeding device for a recording device such as a PPC copying machine, and particularly to a paper feeding device for holding a large amount of recording media by moving a tray that holds the recording media. The present invention relates to the detection of abnormalities in paper feeding devices and control according to the detection results.

[Prior Art] For example, when automatically feeding recording sheets in a copying machine,
A large number of recording sheets are stacked on a paper feeding cassette or tray, and the uppermost recording sheet is fed out by a paper feeding roller disposed above it, so that the paper feeding operation is performed one by one.

In this case, it is necessary to press the topmost recording sheet against the paper feed roller at all times, so generally a compression coil spring is provided below the paper feed cassette so that the plate that supports the group of recording sheets below is placed on top. I am applying force to push it up. Therefore, as the remaining amount of recording sheets decreases, the plate is pushed upward little by little.

However, in order to hold a large number of recording sheets, for example about 1000 sheets, the distance that the plate supporting them must be moved becomes long, and the plate cannot be moved by a simple mechanism such as a spring.

Therefore, in an apparatus that feeds a large amount of paper, an electric motor is generally used to vertically drive a tray that supports recording sheets.

However, in this type of lifting device, a sensor that detects the position of the tray, a sensor that detects the rotation of the electric motor,
If a failure occurs in the electric motor itself, the power transmission mechanism, etc., the electric motor may continue to be driven, or the recording paper conveyor of the copying machine may be seriously damaged due to abnormal pressurization.

Further, if a recording operation (paper feeding operation) is performed in a state where an abnormality has occurred in the elevating device of the paper feeding device, the degree of damage often increases.

[Object of the Invention] The present invention provides a feeding device for a recording device that quickly detects an abnormality in a lifting device of a paper feeding device and, when an abnormality is detected, takes measures to minimize damage that may be caused by the abnormality. The purpose is to provide a paper device.

[Structure of the Invention] In order to achieve the above object, the present invention measures the elapsed time after starting the driving of the elevating mechanism, and detects the operation of the elevating mechanism until the elapsed time reaches a predetermined time. If a predetermined electric signal is not output from the elevating motion detecting means, the notifying means is energized to notify the occurrence of an abnormality. In other words, if no actual lifting/lowering operation is detected for a predetermined reference time or longer even after driving has started, it is assumed that some abnormality has occurred.

Further, a time switching means is provided, and the reference time is switched depending on the state of the time switching means.

In the embodiment described later, the time switching means is a mechanical manual switch whose state is set according to the frequency of the power source used. For example, if the electric motor used as the drive source for the lifting mechanism is a synchronous motor, the frequency of the power supplied to it may be 50Hz or 60Hz.
Z is also fine. However, when the frequency changes, the rotational speed of the electric motor changes.

The time from the start of driving until the actual elevating motion is detected is within a predetermined range between the theoretically possible minimum time and maximum time. Therefore, when detecting the presence or absence of an abnormality, by setting the reference time to a time slightly larger than the maximum time, if an abnormality occurs, it can be detected without delay. However, when the driving speed changes, the maximum time changes.

In other words, the maximum time when the power frequency is 50Hz is T2
If the maximum time in the case of O, 60Hz is T2O, then T2
O>T2O. Therefore, if the reference time is set according to the larger time T50, if the frequency of the power supply actually used by the device is 50 Hz, the actual maximum time T
The difference between 50 and the reference time (T60+ΔT) increases,
There is a time delay in detecting abnormalities.

In the present invention, since the reference time is switched according to the state of the 1-hour switching means, 1. For example, even if the power supply frequency used changes, the most suitable reference time can be set accordingly, so there is a time delay in detecting an abnormality. does not occur.

Other objects and features of the present invention will become apparent from the following description of embodiments with reference to the drawings.

[Embodiment] FIG. 1 shows the internal structure of one type of copying machine that implements the present invention. Please refer to FIG. A document is placed on the contact glass 1 either automatically by an automatic document feeder or manually by an operator. Images of the original document are scanned by an optical scanning system 30 under the contact glass and read sequentially. An optical image corresponding to this image is formed on the photoreceptor drum 2, and an electrostatic latent image corresponding thereto is formed on the drum 2. When the electrostatic latent image passes through the developer 5, it is made visible by toner.

The visualized image, that is, the toner image, is superimposed on the recording sheet fed from the paper feeding system onto the photosensitive drum 2, and is transferred onto the recording sheet by the transfer charger 7. The recording sheet onto which the toner image has been transferred is separated from the photosensitive drum 2 by a separation charger 8 and transported by a transport belt 11. Furthermore, the recording sheet that has undergone the fixing process through the fixing device 12 is conveyed to the sorter 70 and stored in one of the bins of the sorter.

In this embodiment, five sets of paper feeding systems are provided.

The upper four sets of paper feed systems have paper feed cassettes 21, 22, 23
and 24 are provided. These paper feed cassettes are inserted from the outside of the copying machine, and are removably attached to each paper feed port. A paper feed tray unit 25 is provided in the lowest paper feed system. However, it is possible to install the paper feed tray unit 25 in any of the paper feed systems, and it is also possible to install a paper feed cassette in place of the paper feed tray unit in the lowest paper feed system.

Inside the paper feed tray unit 25, as shown in FIG. 4b, a tray 61 and side guides 62, 63 are provided. Approximately 1000 zero recording sheets can be stacked on the tray 61 at one time. The position of the topmost sheet of a large number of sheets stacked on the tray 61 must be kept constant;
In this example, the position (height) of the tray 61 is automatically adjusted electrically.

The tray 61 is fixed on two support shafts 67 shown in FIG. 4a, and the support shafts 67 are driven in the vertical direction by a drive mechanism 66 including an electric motor 65. Tray 6
The lower limit position of 1 is the transmission type optical sensor P shown in FIG. 4b.
Detected by S3. The electric motor 65 has inside thereof a rotary encoder 65a coupled to a drive shaft. This rotary encoder 65a outputs a pulse signal every time the drive shaft of the electric motor 65 makes a slight rotation.

FIG. 2 shows the vicinity of the lowermost paper feed port where the paper feed tray unit 25 is attached. Referring to FIG. 2, a guide member 46 for guiding and supporting the paper feed cassette or paper feed tray unit 25 is provided on the right side inside the paper feed port. Support members 43 and 44 are provided at both upper ends of the front side of the paper feed tray unit 25 to engage with guide members 45 and 46, respectively.

A pickup roller assembly 47 is provided in front of the paper feed tray unit 25. Pickup roller assembly 47
The vicinity of is shown enlarged in Fig. 3. Referring to Figure 3,
A pickup roller assembly 47 and a feed roller 48 are attached to the outer periphery of the drive shaft 51. The feed roller 48 is fixed to the drive shaft 51, but the pickup roller assembly 47 is only supported by the drive shaft 51, and is swingable around the drive shaft 51.

Note that when the paper feed cassette is installed in the paper feed port, the pickup roller assembly 47 is removed from the drive shaft 51.
Only the feed roller 48 is attached to the drive shaft 51.

A pickup roller 81 and a gear 52 are each rotatably supported on the pickup roller assembly 47 . A gear 81a located coaxially with the pickup roller 81 is fixed to the pickup roller 81. The gear 81a is the gear 5
It meshes with 2.

A gear 48a located coaxially with the feed roller 48 is fixed to the feed roller 48, and the gear 48a meshes with the gear 52. Therefore, when the drive shaft 51 rotates, the feed roller 48 rotates, and the pickup roller 81 rotates via the gears 48a, 52, and 81a.

Referring to FIG. 3, inside the paper feed tray unit 25, there are two
Two optical sensors Psi and PS2 are provided. These optical sensors are transmissive optical sensors each comprising a light emitting diode and a phototransistor arranged opposite to each other.

A shaft 53 fixed to the frame 41 of the paper feed tray unit 25 is arranged in front of the optical sensors Psi and PS2.

Two fillers 49 and 50 are each swingably mounted on the shaft 53. One filler 49 has a shaft 53
III supported by! 49a, a light shielding piece 49b provided in the direction of the optical sensor PSI, and an arc-shaped detection piece 49c extending downward. A recording sheet placed on the tray 61 is located below the detection piece 49c. If even one recording sheet is present on the tray 61,
The detection piece 49c is lifted by the recording sheet,
The light shielding piece 49b shields the optical sensor PS1 from light. Tray 6
If there is no recording sheet on 1, the detection piece 49c
is lowered, and the light-shielding piece 49b is removed from the light-shielding position of the optical sensor PS1.Therefore, the signal output from the optical sensor PS1 changes binary depending on the presence or absence of the recording sheet. In other words, the optical sensor p-st functions as a so-called paper end sensor.

The other filler 50 includes a WA supported by a shaft 53.
50a, a light shielding piece 50b provided in the direction of the optical sensor PS2 and a detection piece 50c extending long in the direction of the pickup roller assembly 47 are provided.

The tip of the detection piece 50c extends to a position where it comes into contact with the upper surface of one end 47a of the pickup roller assembly 47.

As shown in FIG. 4C, the recording sheets PAP stacked on the tray 61 are present below the pickup roller 81, and the pickup roller 81 is in contact with the recording sheets PAP under its own weight.

Therefore, when the recording sheet (PAP) is lifted upward, the pickup roller 81 is also lifted.

When the pickup roller 81 is lifted, the detection piece 5
0c is pushed up.

That is, when the position of the uppermost surface of the recording sheet PAP is lower than a certain reference position, the light-shielding piece 50b of the filler 50 shields the optical sensor PS2, but when the position becomes higher than that, the light-shielding piece 50b shifts the light-shielding position of the optical sensor PS2. Take out the karanuki.

Therefore, the signal output from the optical sensor PS2 changes in a binary manner depending on whether the height of the uppermost surface of the recording sheet is equal to or higher than the reference position. Therefore, this optical sensor PS2 is
Functions as an upper limit position sensor for the recording sheet.

As will be described later, the electric motor 65 shown in FIG. 4a is driven to raise the tray 61 when the upper limit position sensor PS2 detects that the position of the uppermost surface of the recording sheet PAP is lower than the reference position. . When the tray 61 rises, the recording sheet PAP placed thereon rises.

When the position of the top surface of the recording sheet reaches the reference position, the upper limit position sensor PS2 detects it and stops driving the electric motor 65.6 Paper feeding operation is performed, and the pickup roller 81 and feed roller 48 , when the recording sheets PAP are sequentially fed out from above, the position of the top surface of the recording sheets becomes lower. In this case, the upper limit position sensor PS2 detects that the 9th position is low, and drives the electric motor 65 again to lift the tray 61.
When the position of the recording sheet reaches the reference position, the raising of the tray 61 is stopped at that position. Therefore, the position of the top sheet is always maintained constant.

FIG. 5 shows an operation board arranged on the top surface of the main body of the copying machine shown in FIG. Referring to FIG. 5, this operation board includes a number of key switches Kl.

K2. 3. 4a, 4b, 5. 6a.

K6b, 7. 8. 9a, 9b, 9c.

KIO, Kll, K12a, K12b, K
13° KC, KS, # and KI, and a large number of indicators Di
.

D2. D3. D4. D5. D6. It is equipped with D7 etc. The indicators D6 and D7 are indicators for displaying the remaining amount of recording sheets in the paper feed tray unit 25 and the occurrence of an abnormality, respectively.

Next, various typical key switches provided on the operation board will be briefly explained.

K1 is a key for specifying the operation mode of the sorter 70, and by operating this key, it is possible to specify any one of a fixed mode (using two seeds), a sort mode, and a stack mode.

K3 is a key for specifying the operation mode of the automatic document feeder 60, and by this operation, one of manual document setting mode, ADF mode, and 5ADF mode can be specified.

K4a and K4b are keys for specifying the front and back margin positions, respectively.

6 a, 6 b, 9 a, 9 b and 9 c.

Used to specify copy magnification.

K7 is used to specify double-sided copy mode.

K8 and Kll are used to specify the document size and paper feed system selection, respectively.

KIO is a numeric keypad and is used to input numerical values, such as specifying the number of copies.

K12a and Kl 2b are used to specify copy density.

KC is the clear/stop key, and the numeric keypad KIO
It is used for clearing input values, instructing to stop copying operations, etc.

KS is a key for instructing to start printing.

FIG. 6 shows the configuration of the paper feed tray unit 25 and the connections to the devices connected thereto. Referring to FIG. 6, the paper feed tray unit 25 is equipped with a microcomputer 251 as a control device. The input boat of the microcomputer 251 includes a paper end sensor Psi,
Upper limit position sensor PS2. Lower limit position sensor PS3. Paper size sensor PS4. rotary encoder 65a,
Tray lowering switch SWI, frequency selection switch SWf
and tray cover switch SW2 are connected.

The frequency selection switch SWf is set according to the frequency of the power supply (commercial AC) connected to the device, and is set at 50
It is set to off in the case of Hz, and on in the case of 60Hz.

Referring to FIG. 4b, the side guides 62 and 63 for positioning the recording sheet are connected to the positioning dial 91.
By rotating the two, the two move in opposite directions in the width direction, and the distance between the two changes. Therefore, by operating the dial 91, the distance between the side guides 62 and 63 can be adjusted to match the size of the recording sheet to be used. The position (angle) of this dial 91 is determined by the paper size sensor PS4 shown in FIG.
Detected in Further, referring to FIG. 4b, the upper surface of the paper feed tray unit 25 is provided with an operation section for a tray lowering switch SW1. The switch SWI is operated when it is necessary to lower the tray 61, such as when replenishing recording sheets. The tray cover switch SW2 shown in FIG. 6 is coupled to the cover 25a shown in FIG. 2, and outputs an electric signal depending on whether the cover 25a is opened or closed.

Referring again to FIG. 6, the microcomputer 251
A driver 253 is connected to the output port of.

Signal lines SG1 and SG2 are respectively drive on/
Used to control off and drive direction switching. An electric motor 65 is connected to the driver 253. Further, the serial communication port of the microcomputer 251 is connected to the main control unit 100 that controls the entire process of the copying machine. In addition to the operation board 200, various units (not shown) are connected to the main control unit 100.

Note that the power used by the paper feed tray unit 25 is supplied from a small power source unit 252 within the unit.

FIG. 7a shows the microcomputer 251 shown in FIG.
An outline of the operation is shown below. The operation will be explained with reference to FIG. 7a.

When the power is turned on, initialization is performed first. That is, the contents of the internal memory are cleared and the states of the input/output ports are set to the initial state. Next, the state of switch SWf is checked. If the switch SWf is off, that is, the power supply frequency is 50
For Hz, register Tl.

T2 and N1 each have a fixed value T a 50. T
b 50 and Na50, and if SWf is on, that is, the frequency is 6 (lHz), registers Tl, T2 and N1
, respectively, with a fixed value T a60. T b60 and N
Store a60.

The value of registration T1 is a reference value for abnormality identification of the time from when the drive of the tray 61 is started until the rotary encoder 65a outputs a pulse for the first time. , and the value of the register T2 is a reference value for abnormality identification of the time from the start of driving the tray 61 until the tray 61 reaches the upper limit position (or lower limit position). Furthermore, the value of the register N1 is a reference value for abnormality identification of the number of pulses output by the rotary encoder 65a after the drive of the motor 65 is stopped. Therefore, the reference values for abnormality identification are all switched according to the switch SWf, that is, the power supply frequency.

Proceeding to step 4, "Busy" information is output to the main control unit 100 to inform that the unit 25 is not capable of feeding paper.

Next, the state of the paper end sensor PS1 is checked. When PSl detects the paper end, it sets the paper end flag FP to 1 and proceeds to step 16. If the paper is not at the end, proceed to step 6, check the state of the cover switch SW2, and wait until the cover 25a is closed.

If the cover 25a is closed in step 6, the process proceeds to step 7, where the state of the lower limit position sensor PS2 is checked. If the sensor PS2 is not off, that is, the tray 61 is not at the lower limit position, the process proceeds to step 14, and the sensor PS2 is on, that is, the tray 61 is not at the lower limit position.
If is at the lower limit position, proceed to step 8.

In step 14, the subroutine ``Paper feed tray lowering'' is executed.As will be described later, when this is executed, the tray 61 is normally positioned at the lower limit position (PS3 is on).Next, the process proceeds to step 15. , the presence or absence of an error is checked. If there is an error, the error flag is output to the main control unit 100 to notify the occurrence of an abnormality.

If there is no error, return to step 7.

In step 8, a "1 paper feed tray rise" subroutine is executed. As will be described later, when this subroutine is executed, the tray 61 is normally positioned at the upper limit position (PS2 is on). Next, the process proceeds to step 9, and the presence or absence of an error is checked.

If there is an error, the error flag is sent to main control unit 1.
00 to notify the occurrence of an abnormality. If there is no error, proceed to step 10.

In step 10, first calculate P m −CN p,
The result is stored in register RP. Here, Pm is a numerical value corresponding to the maximum number of sheets that can be stored on the sheet (for example, 1000 sheets) that can be stored in the paper feed tray unit 25,
CNp indicates a register that holds the number of pulses output by the rotary encoder 65a while the tray 6r moves from the lower limit position to the upper limit position.

Next, since sheet feeding is possible, in order to notify this, "ready" information is output to the main control unit 100, and the contents of the register RP, that is, remaining sheet amount information is output.

In step 11, the state of the upper limit position sensor PS2 is checked, and if it is off, that is, the uppermost recording sheet position is lower than a predetermined value, the process proceeds to step 12, executes the paper feed tray raising subroutine, returns to step 10, and steps again. 11
Proceed to. However, if an error occurs, the process proceeds to step 16.

In step 11, if the sensor PS2 is on, that is, the top recording sheet position is correct, the process proceeds to step 18, where the state of the tray lowering switch SWI is checked. SWI
is off, that is, if there is no switch operation, the process returns to step 11. When the switch SWI is turned on, the process proceeds to step 19.

In step 19, first, main control unit No. 100
``Busy'' information is output, and the subroutine ``Paper feed tray lowering'' is executed. Then, in step 20, it is checked whether there is an error. If there is an error, the process advances to step 16.

If there is no error, check the state of switch SW2. When the switch SW2 is turned off and turned on again, that is, the cover 25a is opened and closed again.
Proceed to step 2 and execute the "Paper feed tray rise" subroutine.Furthermore, the presence or absence of an error is checked, and if there is no error, the process passes through step 10 and returns to step 11.

Therefore, normally steps 11-18-11-18-.
... loop, steps 11-12-13-10-1
1-... loop or steps 11-18-19-
The loops 20-21-12-13-10-11-... are sequentially processed.

The details of the "Paper feed tray rise" subroutine and the "Paper feed tray lower" subroutine in FIG.
It is shown in Figure b and Figure 7C. First, referring to Figure 7b,
The ``Paper Feed Tray Raise'' subroutine will be explained. In the following description, step numbers are shown in parentheses, and "step" is omitted.

First, clear the contents of register CNp and timer CNp.
t is cleared and started, and the motor 65 is set to normal rotation drive (51).

Next, the presence or absence of the first pulse from the rotary encoder 65a is checked (52). At first, no pulse is detected, so next the state of the upper limit position sensor PS2 is checked (62). Since the sensor PS2 is initially off, the contents of the timer CNt are then compared with the contents of the register T1 (63). Since the value of CNt is initially smaller than T1, the presence or absence of the first pulse is checked again (52).

(52) -(62) -(63) -(52)-...
The first pulse is normally detected while passing through the loop . and the process proceeds to the next process (53). Due to some abnormality,
If the first pulse is not detected for a long time, the content of CNt becomes larger than T1 (63), so the abnormality flag FE
Set I (64) and stop the motor 65 (58)
. Note that the content of T1 is set to a value of about 2 degrees, for example.

When the first pulse is detected, then register CNp
The content of is incremented (+1) L (53), and the presence or absence of the second and subsequent pulses is checked (54). Each time a pulse is detected, the contents of CNp are incremented (
53).

When no pulse is detected, paper end sensor PS1.
Tray cover switch SW2. Upper limit position sensor PS, 2
Check the status of (55°56.57) one after another. When the paper end sensor PS1 is turned on, the paper end flag FP is set (65,) and the motor 65 is stopped (58). Further, when the tray cover switch SW2 is turned off, the counting of the motor 65 and the timer CNt is stopped (66), and the process waits until the SW2 is turned on again (67). S
When W2 is turned on, the motor 65 is restarted and the stoppage of the timer CNt is canceled (68).

While the upper limit position sensor PS2 is off, the contents of the timer CNt are compared with the value of the register T2 to check for errors (69). When CNt>T2, it is regarded as a time-over error and the error flag FE2 should be set.
0), the motor 65 is stopped (58), and the content of T2 is set to a value of 1, for example, about 10 seconds.

When the upper limit position sensor PS2 is turned on during the upward drive or when the error flag FEI or FE2 is set, the drive control of the motor 65 is stopped and the contents of the register CNo and the timer CNt are cleared (58).

Next, the contents of timer CNt are compared with the contents of register TO (59). A predetermined fixed value is stored in the register TO. While CNt>To, the presence or absence of a pulse from the rotary encoder 65a is checked 60), and when a pulse is detected, the contents of register CNo are incremented 61), and the contents of CNt are compared with the contents of To again (59). .

When CNt>To, that is, when a predetermined time period determined according to the contents of TO has elapsed since the motor 65 was set to a stopped state, the contents of the timer CNt are compared with the contents of the register N1 (71). And as a result, CN o > N
If it is 1, that is, if the number of pulses detected after stopping the motor 65 is greater than or equal to a predetermined value, it is regarded as an overrun error, and an error flag FE3 is set (72).

Therefore, when the paper feed tray raising subroutine is executed, if there is no abnormality, the electric motor 65 is activated to raise the tray 61 to the position where the upper limit position sensor PS1 is turned on.
control. Furthermore, if the time from the start of driving the electric motor until the pulse of the rotary encoder is detected is longer than the content of T1, an error flag FEI is set, and the time from the start of driving the electric motor to the detection of the pulse of the rotary encoder is set, and
If the time until S1 turns on is longer than the contents of T2, an error flag FE2 is set, and if the number of rotary encoder pulses detected after stopping the lψ movement of the electric motor exceeds the contents of N1, an error flag is set. F'E3 is set. Note that the values stored in -TI, T2, and N1 are set to the minimum values that can identify the presence or absence of an error. For example, the value of T2.

There is a small margin in the theoretical maximum time required to drive the tray 61 upward from the state where the lower limit position sensor PS3 is on until the upper limit position sensor PS2 is on when there is no recording sheet on the tray 61. This value corresponds to the sum of time.

However, this time varies depending on the frequency of the power source used because the driving speed of the electric motor 65 changes when the frequency of the power source used by the device changes. Therefore, in this embodiment, TI, T2 and N
It is designed to switch the value of 1.

The contents of the ``Paper feed tray lowering subroutine'' shown in Fig. 7c are mostly the same as the ``Paper feed tray raising'' subroutine described above. In place of the reverse drive, the upper limit position sensor PS2 is changed from the upper limit position sensor PS3 to emit a signal for identifying the target position.The other processes are the same, so a detailed explanation of the processes will be omitted.

FIG. 8a shows a schematic operation of the main control unit 100 of FIG. 6. This will be explained with reference to FIG. 8a.

When the power is turned on, the CPU initialization process in step SAI is first performed to initialize the state of the main control board itself.

That is, the contents of the read/write memory are cleared, various mode settings are initialized, and the output ports are reset.

Next, the initial setting process of step SA2 is performed.

In this process, the states (operation modes) of various boards and devices connected to the main control board are initialized, and the copying machine is set to its initial state.

It also sets the timer mode and count value.

In step SA3, standby mode processing is performed.

At this point, the copying operation is stopped and the copying machine is in a standby state. In this process, the following process is performed.

First, the states of signals applied to various input ports are read and the results are stored in memory. Next, a group of output control data stored in advance in the memory is outputted to an output port associated with each data to control a device connected to the output port. Furthermore, the states of various input ports that have been read in advance and stored in the memory are determined, and the presence or absence of an abnormality is checked. If there is an abnormality, predetermined abnormality processing is executed. If there is no abnormality, the status of other input ports is determined and, for example, input from the operation board 200 is processed. It is determined whether there is key human power or not, and if there is key human power, processing is performed according to that key human power. For example, in normal operating mode, the numeric keypad KI
When there is an input from O, the numerical value associated with the pressed key is stored in the copy number register. Also, if there is an input from 6 a, 6 b, etc. on the magnification adjustment key,
A magnification adjustment instruction signal is sent to an optical system control board (not shown).

Further, the display data stored in the memory in advance is output to a predetermined output port at a predetermined timing, and the data is displayed on various displays on the operation board 200.

If the copying is not possible or if the print start key KS is not turned on, the standby mode processing described above is repeatedly executed. Copying is not possible if, for example, the fixing temperature is outside a predetermined range or if some abnormality is detected.

When the print start key KS is pressed in the copy enabled state, the pre-copy mode process of step SA6 is executed. In this processing, as processing immediately before starting the copying process, the driving start of the main motor, the pre-copying cleaning processing of the photosensitive drum, the paper feeding processing, etc. are performed. The number of copies (NK) previously entered at 10 on the numeric keypad is stored in the number of copies set value register N5et, and the start flag is reset.

When step SA6 is completed, copy mode processing in step SA7 is executed. At this point, the copy process is actually executed. This processing includes copy process processing 9 paper transport processing and toner replenishment processing.

This includes abnormality check processing, etc. In the copy process, various process elements are controlled on/off at predetermined timings synchronized with output pulses from a timing pulse generator that generates pulses corresponding to the amount of rotation of the main motor. ■Repeat the copy mode processing until the cycle's copy process is completed, and when it is completed, increment (+1) L the copy number counter Ccopy and compare the result with the contents of the copy number set value register N set. .

CCopy=N set: If not, the process goes to copy mode processing SA7 again and starts the next copying operation.

When Ccopy = N set, that is, when the copy mode processing in step SA5 is completed for the final copy, the contents of the counter Ccopy are cleared and the process proceeds to step 5.
A12 post-copy mode processing is executed. In this process,
Ejecting paper with copied images transferred to it.

After copying the photosensitive drum, cleaning processing, etc. are performed. When the paper discharge is completed, the process returns to the standby mode process of step SA3 and the above process is repeated.

Part of the display processing included in the standby mode processing etc. of FIG. 8a is shown in FIG. 8b. See Figure 8b. First, the error flag FEI sent from the paper feed tray unit 25
, FE2. Check the status of FE3. FEI, FE
2. If either FE3 is set to It 1 '7, the display D7 on the operation board 200 is controlled to light up to indicate a paper feeding abnormality.

Next, the paper end flag FP is checked.

If the flag FP is set, "" on the operation board
Turn off the "Ready to copy" display (see Figure 5).

Subsequently, the paper is fed from the paper feed tray unit 25.

Check busy/ready information. If it is busy, turn on the "Please Wait" display on the operation board and reset the copy permission flag. Once the copy permission flag is reset, copy operations are prohibited until it is set next time. If it is ready, turn off the ``Please wait'' display on the operation board, turn on the ``Ready to copy'' display, and set the copy ready flag. Also, the register RP sent from the paper feed tray unit 25 Depending on the content of
Controls the display on the display D6 on the operation board. As a result, the remaining amount of sheets in the paper feed tray unit 25 is displayed on the display D6.

In the embodiment described above, each register Tl, T2 .
Although the setting of the value of Nl is changed according to the state of the manual switch SWf, the switch SWf may be replaced with means for automatically identifying the power supply frequency. Although not shown, this means includes, for example, a zero-cross detector that emits a signal at the zero-cross point of the power supply voltage waveform, and a counter that measures the interval or period of the signal output by the detector.

And according to the counting result of the counter, 50Hz/60H
It consists of a comparator that identifies the frequency in either z.

[Effects] As described above, according to the present invention, when an abnormality occurs in a paper feeding device equipped with an electric lifting mechanism, it is immediately notified, so that appropriate measures can be taken before a serious failure occurs.

[Brief explanation of drawings]

FIG. 1 is a front view showing the structure of a mechanical section of one type of copying machine embodying the present invention. 2, 3, 4a, and 4b are perspective views showing the whole or part of the paper feed tray unit 25, and FIG. 4c shows the recording sheet PAP, the pickup roller 81. FIG. 3 is a front view showing the positional relationship of filler 50 and the like. 5- is a plan view showing the appearance of the operation board 200 of the copying machine shown in FIG. 1. FIG. FIG. 6 is a block diagram showing the electrical circuit configuration of the paper feed tray unit 25. As shown in FIG. 7a, 7b, and 7c are flowcharts showing the operation of the microcomputer 251 shown in FIG. 6. 8a and 8b are flowcharts showing a part of the operation of the main control unit 100 shown in FIG. 6. FIG. 25: Paper feed tray unit 61 (sheet loading table) 65: Electric motor (Electric YB moving unit 65a: Rotary encoder (elevating motion detection means) 66: Drive mechanism (
Lifting mechanism) 100: Main control unit 200: Operation board 251: Microcomputer (electronic control means) Psi
:Paper end sensor PS2: Upper limit position sensor (lifting/lowering instruction means) PS3: Lower limit position sensor (lifting/lowering instruction means) PS4: Paper size sensor SW1 Nidorei lower switch (lifting/lowering instruction means) SW2 Nidlei cover switch (lifting/lowering instruction means) SWf: Manual switch (time switching means) D1 to D6; Display D7: Display (notification means)

Claims (1)

[Scope of Claims] Recording means for performing predetermined recording processing; A sheet mounting table for holding recording sheets to be supplied to the recording means; An elevating mechanism for adjusting the position of the sheet mounting table; Lifting instruction means for instructing the start; Electric drive means for driving the lifting mechanism; Lifting operation detection means for outputting an electric signal according to the movement of the lifting mechanism; Notification means for notifying the occurrence of an abnormality; Time switching means; When the elevating/lowering instruction means is turned on, it starts driving the electric drive means and starts measuring time, and the elevating/lowering is started until the measured time reaches a predetermined time depending on the state of the time switching means. A paper feeding device for a recording apparatus, comprising: electronic control means that energizes the notification means when a predetermined electric signal from the motion detection means is not detected.