JPS63212649A - Recording device - Google Patents

Abstract

PURPOSE:To make it possible to always detect precise operation of paper feed by continuing drive for conveyance until the operation of paper feed is completed even though a paper jam is detected during paper feed. CONSTITUTION:When a paper feed solenoid SL201 is energized in response to a paper feed drive signal, a paper feed clutch 410 is engaged so that a crescent shape paper feed roller 402 is rotated by one revolution. At this time the true period of the paper feed drive signal is shorter than that of the revolution of the paper feed roller 402, but the paper feed roller 402 is rotated by the drive power of a paper conveying system until the paper feed clutch 410 is disengaged after one revolution of the paper feed roller 402. When a paper jam is detected during rotation of the paper feed roller 402, the paper feed solenoid drive signal is turned on, and simultaneously, the time period (Tc) of one revolution of the paper feed roller 402 is monitored, and if a paper jam occurs during that period, the drive of conveyance of paper is interrupted after the time period (Tc) elapses. Accordingly, even though a jam occurs any time, the paper feed roller 402 is always set at a normal rotating position, thereby it is possible to perform normal paper feed operation.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a recording apparatus having a paper feed device in which a paper feed roller is operated by a drive device for paper conveyance.

[Prior art]

Conventionally, in this type of recording apparatus, when a paper jam occurs during a printing operation, the printing operation is immediately interrupted. Further, in a recording apparatus in which a half-moon-shaped paper feed roller is rotated by a paper conveyance drive device, the maximum load torque occurs during paper feeding operation.

By the way, if the recording device detects a paper jam while the paper feed roller is rotating and interrupts the paper conveyance operation, the paper feed roller will stop mid-rotation. Therefore, when attempting to operate the paper conveyance system again after the paper jam is cleared, the maximum load torque is reached when the drive device starts up. When a pulse motor is used as the drive motor, the pull-in torque is smaller than the pull-out torque, so under the above conditions there is a possibility of tax adjustment.

〔the purpose〕

In order to eliminate the above-mentioned drawbacks of the conventional example, the present invention provides control so that when a paper jam occurs during paper feeding operation, the drive of the paper conveyance system is not interrupted until the paper feeding operation is completed, so that the paper feeding operation is always accurate. The object of the present invention is to provide a recording device that can perform the following operations.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a control circuit diagram of the laser beam printer in this embodiment, and in the figure, 201 is a one-chip microcomputer with built-in ROM (hereinafter referred to as CPU 201).
, ANO-AN7 is an analog input port, PA3
~PA7. PBO-PB7. PC3 is input port, PA
O, PA2. PCO~PC2, PC4~PC7゜PDO
~PD7. PFO to PF7 are output ports. 202
is a controller that receives signals from the host computer 213 and controls image formation for the printer. 20
4 is a pre-exposure lamp that uniformly erases the potential on the photosensitive drum 1008; 205 is a high-voltage unit that generates high voltage in response to a high-voltage drive signal from the CPU 201; and 206 is a high-voltage unit that contains toner and generates an image by receiving the laser from the semiconductor laser LS 201. 207 is the CPU 201
This is a fixing heater drive circuit that receives a fixing heater drive signal from the fuser heater drive circuit and turns on and off the gate of the triac transistor. 208 is a one-chip microcomputer (hereinafter referred to as CPU 208) with a built-in ROM, which is the same as 201, and receives control signals from the CPU 201 to control the amount of laser light,
Controls pulse motor (Ml) drive. 209 is CPU
a polygon motor drive circuit that receives a polygon motor drive signal from 201 and rotates the polygon motor M3 at a constant speed;
210 is a laser drive signal from the CPU 208 and 212
A laser circuit receives a laser control signal from the gate array, emits and receives a laser, and feeds back the amount of laser light to the CPU 208. 211 is a beam detection circuit that inputs the light received by the optical fiber 1009 in FIG. 1O to the gate array 212. It is. 212 is CPU
Based on the image width information sent from the controller 208 and the image signal from the controller 202, it controls the on/off of the laser according to the image signal during image formation, and receives the beam detection signal and the signal from the polygon motor drive circuit. This is a gate array that monitors the polygon motor and beam detection signal. In addition, in FIG. 1, the gate array 212
are shown separately as 212a and 212b in the drawing,
They are actually made up of the same chip. In addition, the part surrounded by dotted lines in FIG. 1 corresponds to the control section (print controller) excluding the sensor and drive system.

FIG. 2 is a diagram showing a connection state between a low voltage source and a print controller.

In Figures 1 and 2, when the power switch of 5W181 is turned on, +5V is first output from the low voltage power supply of 101.
At the same time, a reset signal RESET (
A signal (hereinafter referred to as RESET signal) is output.

In response to the RESET signal, the CPU 201 starts control,
After completing the initialization of each unit of the main body, the printer power ready signal PPRDY is sent to inform external devices such as the controller of 202 that the power of the main body has been turned on.
(hereinafter referred to as PPRDY signal). This PP
The RDY signal is also connected to the low voltage power supply 101 at +24VA, +
24VB and -5V output control signal REMOTE (
This signal is output as a REMOTE signal (hereinafter referred to as a REMOTE signal). The low voltage power supply 101 outputs +24V and -5V when this REMOTE signal becomes true.

The CPU 201 that outputs the PPRDY signal then outputs the motor drive signal DRMD to the CPU 208 for a certain period of time, during which time the CPU 208 outputs an excitation signal for the pulse motor.

In response to this, the low voltage power supply 101 initially rotates the pulse motor Ml, which is the drive motor of the paper conveyance system.

This is the photosensitive drum 1008 inside the EP cartridge 206.
This is to cause the gears of the paper conveyance system to engage with each other. At this time, the CPU 201 outputs the registration solenoid drive signal REGD to connect the clutch 405 shown in FIG. The drive rotates the registration roller 404. If there is residual paper in the paper conveyance unit and the initial rotation of the motor can convey the residual paper to the position of the paper discharge sensor PS201, the CPU 201 detects that there is residual paper in the machine, Do you want to automatically eject the remaining paper?
Alternatively, it will cause a paper jam and indicate to the operator that there is residual paper in the machine. In addition, the motor drive signal DRM
Since D is used together with the polygon motor drive signal 5CNON and the pre-exposure lamp drive signal PEXP, the polygon motor M3 and the pre-exposure lamp 204 simultaneously rotate at the initial rotation of the motor.
is also driven. However, during this initial rotation of the motor, the laser is not output even if the polygon motor M3 starts up, so the beam detect signal B indicating the beam scanning position is not output.
D (hereinafter referred to as BD double signal) is not monitored.

After the initial rotation of the motor is completed, the CPU 201 detects the amount of toner remaining in the EP cartridge 206. First, the high voltage unit 205 receives the developing bias AC from the CPU 201.
It receives a minute drive signal DBAC (hereinafter referred to as DBAC) and a transfer high voltage drive signal HVTON (hereinafter referred to as HVTON signal), and supplies a developing bias into the developing cylinder. At this time, the remaining toner amount detection sensor 220 installed inside the cartridge 206 detects the remaining amount of toner, and the high pressure unit 205 detects the remaining amount of toner.
After that, the CPU 20 outputs the toner sense signal TSENS.
It is input to analog input port 1.

The control program of the CPU 201 does not detect the remaining amount of toner at the same time as outputting the high-voltage drive signal, but rather maintains a certain period of time and performs the detection after the high-voltage output has sufficiently risen. Further, the remaining amount of toner is detected also during printing operation, and the print signal PR from the controller 202 is detected.
NT (hereinafter referred to as PRNT signal), the primary high voltage P1, the DC portion of the developing bias DB, and the transfer high voltage T are output in this order from the high voltage unit 205, and after a certain period of time after the AC portion of the developing bias DB rises. Toner remaining amount detection starts and ends at the same time as the DBAC signal from the CPU 201 is cut off. Since the remaining toner amount detection signal TSENS varies with each rotation period of the photosensitive drum 1008, the CPU
The control program 201 performs a detection method as shown in FIG. In FIG. 3, in step 300, it is determined whether or not the remaining amount of toner can be detected. If it is possible, the process proceeds to step 301. Already in step 301 the LED
When the insufficient remaining amount of toner is displayed by 200, no new detection of the remaining amount of toner is performed. NO in step 301
If so, in step 302, a counter l for determining whether the remaining toner amount is insufficient is reset. Next step 303. Step 3
At step 04, the average value counter 2 and buffer of the remaining toner amount detection signal are cleared. Next, if the continuous reading N times is not completed in step 305, the remaining toner amount detection signal TSEMS is read in step 306, the integrated value is saved in the buffer in step 307, and counter 2 is counted in step 308. The process returns to step 305. If it has been read N times in step 305, step 30
Step 9 calculates the average value. The result is compared with a reference value for insufficient remaining toner, and if it is determined in step 310 that there is insufficient remaining toner, a counter l for determination is incremented in step 311. Step 3 if there is not enough toner remaining
Returning to step 02, the remaining amount of toner is detected again. Step 3
When the counter 1 counted up in step 11 reaches M times in a row, in step 313 the LED 200 is used to display the insufficient amount of toner remaining.

If it is not M times in a row, the counter is left as is, and the remaining toner amount detection is read again from step 303.

As described above, by taking the average value of the remaining toner amount detection signal TSENS and further determining whether the remaining amount of toner is insufficient M times in succession, it is possible to cope with fluctuations in the remaining toner amount detection signal TSENS every cycle of the photosensitive drum 1008. Unambiguous judgment results can be obtained. In addition, if the remaining amount of toner is insufficient once displayed, when the cartridge 206 is replaced, the CPU 2
It is held until 01 makes a decision. A determination as to whether the cartridge 206 should be replaced is made as follows.

FIG. 11 is a schematic diagram of the laser beam printer of this embodiment. In FIG. 11, the upper door 11 of the printer 401
The micro switch 5W100 in the low voltage power supply 101 that is linked to the lever 1103 attached to the upper door 11
It turns off at the same time as 01 is opened, cutting off the 24VB and motor drive (7) 24V power supplies. CPU201 is the same 2
A DC 24V signal obtained by dividing 4VB (hereinafter referred to as a DC 24V signal) is input, and upon detecting that the DC 24V signal has become a low level, it is determined that the upper door 1101 has been opened. In order to replace the cartridge 206, the upper door 1101 must be opened, so C
The PU 201 can predict that the cartridge 206 will be replaced when the upper door 1101 is opened. By opening the upper door 1101, the CP
In order to ensure the safety and control reliability of the printer 401, U201 jumps to the beginning of the program to reset its own processing and redo the initial settings. At this time, L
After the display of the insufficient amount of toner by the ED 200 is reset and the upper door 1101 is closed, the first remaining amount of toner is detected again after the initial rotation of the motor.

When the upper door 1101 is closed, the lever 1103 attached to the upper door 1101 pushes the micro switch 5W100 in the low voltage power supply 101, and the CPU 20
24V is output from the low voltage power supply 101 which receives the REMOTE signal from microswitch 5.
Considering chattering caused by turning on and off the W100, or the fact that the upper door 1101 is incompletely closed due to operator error, the CPU 201 immediately starts up the printer 401 even if the DC 24V signal becomes high level. Wait until the upper door 1101 is completely closed after leaving the blank for a certain period of time before turning on the printer 40.
Launch 1.

Since the control program is reset when the upper door 1101 is opened, the PPRDY signal becomes false, but since +v5 from the low voltage power supply 1O1 is rising, after the control program is reset, the PPRDY signal becomes false when the upper door 1101 is opened. I'll come back though. Therefore, the controller power ready CPRDY signal output from the controller 202 (
If the CPRDY signal (hereinafter referred to as CPRDY signal) is true, communication with the controller 202 is also possible. At this time, controller 2
If there is a status request from 02, the printer 401 replies to the controller 202 with the status that the upper door 1101 is being opened.

After the initial rotation of the motor Ml and the detection of the remaining amount of toner, the printer 401 enters a warming-up state.

At this time, if the controller 202 is connected, the printer 401 returns a waiting status in response to the status request from the controller 202. During warming up, the temperature of the fixing heater H1 of the fixing device 413 is adjusted, and the fixing roller 411 is heated to the standby temperature T.

A pulse signal of the fixing heater drive signal FSRD (hereinafter referred to as FSRD signal) is sent from the CPU 201 to the power input section 207.
The power input unit 207 drives the triac Trl to heat the fixing heater H1. When the fixing roller 41] reaches the standby temperature T1, the main body enters a stop state and returns to the controller 202. The waiting status is canceled and the CPU 201 then returns to the controller 202 until the print operation starts.
is the fixing heater H1 so that the standby temperature T1 is maintained.
control. The printer 401 can perform cassette feeding or manual paper feeding in response to a paper feeding mode designation command from the controller 202. If no paper feed mode designation command is sent, the printer assumes cassette paper feed mode. In the case of the cassette paper feeding mode, the printing is enabled when the following conditions are met, and the printing operation is started or continued when the PRNT signal from the controller 202 becomes true.

(1) The EP cartridge 206 is set.

(2) The controller power ready CPRDY signal is true.

(3) No paper jam occurs.

(4) There is no failure or misprint in the fixing device, polygon motor M3, or beam detect signal BD.

(5) The cassette 408 is installed and paper is set inside.

The presence or absence of the EP cartridge 206 is determined by another control CPU 208 in the printer that controls the drum sensitivity sense frame 1102 of the EP cartridge 206 using the micro switch 5.
It is determined by turning on W210 and 5W211, and if there is no cartridge 206, it sends an EP cartridge no signal N0CRT (hereinafter N0C
RT signal) is output. If the N0CRT signal is false, the EP cartridge 206 is present.

The controller power ready signal CPRDY is a signal input from the controller 202.
This is the only signal that can detect the rising state of 02.

In (3) and (4) above, except for the fuser failure, printer 4
This is a condition that can be detected only when printing is performed at least once after 01 rises, and polygon motor failure occurs even if a certain period of time has elapsed after polygon motor drive signal 5CNON becomes true. does not rotate at a constant speed, and the polygon motor ready signal 5CNRDY (hereinafter referred to as 5CNRDY) from the polygon motor drive circuit 209
signal) does not become true, or 5CN
This is a case where the RDY signal once becomes true and then remains in color for a certain period of time.

The misprint is due to an abnormality in the BD double signal obtained by the rotation of the polygon motor M3, and the CPU 201
Signal BDERR (hereinafter referred to as B
DERR signal): Determined when true is input, and furthermore, if the BDERR signal continues for a certain period of time, the BD
It is judged to be a failure. The failure of the fixing device is caused by the temperature T of the fixing roller 411 detected by the thermistor THI.

The signal FSRTH (hereinafter referred to as FSRTH signal) is CP
This is the case when the FSRTH signal input to U201 is outside the control temperature range, or when it is determined that the thermistor THI is disconnected or the fixing heater H1 is disconnected. When the fuser malfunctions, the CPU 201 sends a signal FSERER signal (hereinafter F
SERER signal) is output, and the capacitor C21
Charged up to 1. The charge that has been charged up in the capacitor C211 is gradually discharged after the power is turned off, but if the power is turned on before reaching a certain level, it is determined that the fixing unit has failed again, and the charge is charged up in the capacitor C211 by the FSERER signal. The paper jam condition can be determined based on the jam detection timing described later.
This is determined when a paper jam occurs.

In the paper cassette 408, as shown in FIG. 4, a top 412 attached to the tip of the paper cassette is input to the CPU 201 as signals PSIZEI to PSIZE3 by turning on any of the microswitches 5W201 to 3W203. It is determined that there is a paper cassette. Since the position of the frame 412 of the paper cassette differs depending on the paper size handled, up to seven paper sizes can be detected by determining whether the microswitches 5W201 to 5W203 are on or off. Further, the presence or absence of paper in the paper cassette 408 can be detected by determining the signal PEMP from the paper sensor PS202.

When all of the above conditions are satisfied and a printable state is reached, a printable signal RDY (hereinafter referred to as RDY signal) is sent from the printer 401 to the controller 202. Further, if the above-mentioned conditions are not satisfied, the printer 401 can return the status of the above-mentioned conditions to the controller 202 as a status if there is a status request from the controller 202.

When a manual paper feeding command is sent from the controller 202, the printer 401 enters the manual paper feeding mode from printing the next page, and becomes ready for printing when the following conditions are met. Conditions (1) to (4) for printing in the cassette paper feeding mode described above are satisfied, the paper cassette 408 is installed, and the paper 407 is set in the manual feed slot.

In FIG. 4, manual paper feeding is performed by feeding paper 407 along a manual feeding guide 406 on a paper cassette 408 to a paper feeding roller 4.
Paper cassette 4 must be inserted up to 02.
The structure is such that manual paper cannot be set without 08. Therefore, the CPU 201 first detects that the paper cassette 408 is installed using the paper cassette size detection signals PSIZEI to PSIZE3, and then detects the signal MPFS (hereinafter referred to as MPFS signal) from the manual paper detection sensor PS203 in the manual paper feed port. ) is input to determine the presence or absence of manual paper. In the manual paper feed mode as well as in the cassette paper feed mode, the controller can return the print enable signal RDY or, if printing is not possible, the status.

FIG. 14 is a flowchart showing the determination of the presence or absence of paper depending on the above-mentioned paper feeding mode. Regardless of the paper feeding mode, in step 1401, the presence or absence of a paper feeding cassette is first determined based on the paper feeding cassette size signal PSrZE I~3, and if there is a paper feeding cassette, then in step 1402, whether or not the paper feeding mode is manual feed mode is determined. to judge. If it is the manual paper feeding mode, the presence or absence of manual paper is determined in step 1403 based on the MPFS signal, which is a manual paper detection signal. If there is paper, the controller 20 at step 1404
The paper out bit of the status transmitted to No. 2 is reset, and if there is no paper, the paper out bit of the status is set in step I408. Other printability conditions are checked in step 1405, and if printing is possible, the ready display is turned on in step 1406, and if printing is not possible, the ready display is turned off in step 1409.

If the cassette paper feeding mode is selected, the presence or absence of paper in the cassette is determined in step 1407 based on the cassette paper detection signal PEMP. The subsequent procedure is the same as in manual paper feeding mode.

However, the analog input port RDYIN of the CPU 201
By setting the H signal to a low level using the 5W212, among the above-mentioned printable conditions, presence or absence of the EP cartridge 206, presence or absence of paper jam, failure of the polygon motor, beam detect signal, misprint, presence or absence of the paper cassette 408, paper It is possible to set the printable state regardless of the presence or absence of paper in the cassette. However, in the manual feed mode, printing is possible, and even if the print signal PRNT from the controller 202 is received, the printing operation will not start unless there is paper in the manual feed slot and the MPFS signal becomes true. In addition, even if a printable condition is created by setting the signal RDY■NHDBAC to ignore the printable condition, the above-mentioned conditions will continue to be detected, and if a printer status request is made from the controller 202, the detected result will be used as the status. return. This also applies before, during, and after the printing operation. After the printer 401 becomes ready to print,
When the controller 202 sends out the print signal PRNT, the CPU 201 receives it and controls the print operation in the sequence shown in FIG. First, the motor drive signal DRMD is set to true, and the paper conveyance motor M1 is driven. At the same time, the polygon motor drive signal 5CNON and the pre-exposure lamp drive signal PEXP are made true. Thereafter, the high voltage drive signals -arrow high voltage HVION, developing bias DC portion DBDC, and transfer high voltage HV TON are turned on in sequence.

Further, t1 seconds after the motor is driven, the paper feed solenoid 5L2
In order to drive the paper feed drive signal CPUD (hereinafter referred to as CPU
D signal) is true. True period t of CPUD signal
The CPU calculates the time t for the half-moon-shaped paper feed roller 402 to rotate once.
Although it is shorter than c, the paper feed solenoid 5L201 is driven,
When the paper feed clutch 410 is connected, the half-moon-shaped paper feed roller 4
02 is rotated by the driving force of the paper conveyance system until the paper feed clutch 410 is disengaged after one rotation.

After turning on the CPUD signal, the CPU 201 sends a laser power control start signal APC3T (hereinafter referred to as A) to the CPU 208 in order to perform laser power control after confirming that the polygon motor is ready.
PC3T signal) is output. The CPU 208 is an AP
Upon receiving the C3T signal, the laser power is controlled by input/output to the laser drive circuit 210 to maintain a constant level. At this point, the printer is ready for image formation.

Next, the CPU 201 instructs the controller 202 to
Time t from D signal on. After that (variable depending on the rise condition of the polygon motor), a vertical synchronization signal request VSREQ (hereinafter referred to as the VSREQ signal) is output. controller 20
When the image output preparation is completed from 2, the vertical synchronization signal VSYN
C (hereinafter referred to as a VSYNC signal) is returned, and the CPU 201 is in a waiting state during that time. If the print signal becomes false during this time, the CPU 201 determines that printing has been canceled and enters post-processing of the printing operation to output a blank page. When the vertical synchronization signal VSYNC is sent from the controller 202, the CPU 201
In order to drive the registration roller driving solenoid 5L202 after a certain period of time t2 based on the leading edge of the NC ON signal,
Drive signal REG for registration solenoid 5L202
Make D signal true. Further, after t3 from the leading edge of the VSYNC signal being turned on, the DBAC signal is made true to drive the developing bias AC.

Furthermore, the image mask signal TOPER5 in the sub-scanning direction is set to VS
It turns off t4x seconds after the leading edge of the YNC signal and turns on t4 seconds depending on the paper size. While the image mask signal TOPER8 in the sub-scanning direction is on, the controller 2
Even if the image signal VDQ is input from 02, no image is formed because the laser is not output.

The paper conveyed by the registration roller drive reaches a paper discharge sensor PS201 installed near the fixing device. Therefore, the CPU 201 operates at a time t from the leading edge of the VSYNC signal ON.
5, it is detected that the signal PDP (hereinafter referred to as PDP signal) from the paper discharge sensor PS201 is true, and it is confirmed that the paper has been correctly fed and conveyed. If VSY
If the PDP signal is false after time t5 from the leading edge of the NC signal being turned on, it is determined that there is a delay jam. Time t elapses from the leading edge of the VSYNC signal on after the image signal transmission from the controller ends.
6, if it is ready to print, the next PR
The NT signal receiver sets the print request status to recognize that attachment is possible. After sending the image signal, the controller 202 makes this status request and returns P.
The RNT signal may be true. CPU201 is VSYN
If the next PRNT signal is not sent from the controller 202 by one time period after the leading edge of the C signal ON, or if the printer is not ready for printing (if so, post-processing of the printing operation will begin. If the PRNT signal is not sent by time t7) If the signal becomes true, the print sequence from the CPUD signal on described above is taken again.From the leading edge of the VSYNC signal on, time t
After 8, the paper on which the image has been formed should have passed the paper discharge sensor PS201, so the CPU 201 outputs VSYN.
Since the PDP signal is false after time t7 from the leading edge of the C signal, it is confirmed that the paper has correctly passed the paper discharge sensor PS201. If the FDP signal is true at this time, the CPU 201 determines that a retention jam has occurred. Normally, when a paper jam occurs, the paper conveyance drive is immediately interrupted and a jam status is set to make the controller 202 recognize that a jam has occurred. However, when continuous printing is performed, a paper jam may be detected while the paper feed roller 402 is rotating depending on the printing interval. At this time, the CPU 201 outputs the paper feed solenoid drive signal C.
At the same time as the PUD is turned on, the time tc for one rotation of the paper feed roller 402 is monitored, and if a paper jam occurs between the time when the CPUD signal is turned on and the time tc, the paper conveyance drive is interrupted after the time tc. The same goes for setting paper jam status. Therefore, no matter when a paper jam occurs, the paper feed roller 402 is always placed at the normal rotational position.

FIG. 13 is a flowchart showing the paper feed control and jam control described above.

If the print timer is on in step 1201, the print sequence has already entered, so the process moves to step 1205. If the print timer is off in step 1201, the process advances to step 1202, and step 1202. If the PRNT signal is true in step 1203 and the printer is ready for printing, the print timer is turned on in step 1204. Otherwise, reset the timer to 12. In step 1205, if it is paper feeding timing, a paper feeding timer is started in step 1206. If a jam occurs during subsequent control, only the jam flag is turned on in step 1208 without processing the jam on the spot. After performing other control checks, step 12
If the jam flag indicating the occurrence of a jam is on in step 09, it is determined in step 1210 whether the paper feed timer is running. This paper feed timer is set at step 1205゜1.
At step 206, a timer started at the time of paper feeding counts the time tc during which the paper feeding roller 402 is rotating, and is then cleared. If the paper feed timer is on in step 121O, the paper feed roller 402 is rotating, so the jam processing in step 1211 is not performed, and the jam processing in step 1211 is performed after the time tc when the paper feed roller 402 has stopped. Jam processing involves resetting the timer, stopping the conveyance system, and setting the jam status.

If paper cassette 4 is inserted during image formation in cassette paper feed mode,
Even if the paper sensor PS202 in 08 indicates that there is no paper, or the microswitches 5W201 to 5W203 indicate that there is no cassette, the paper on which image formation is currently being performed is already being conveyed, and furthermore, the controller 202 The image being formed must be guaranteed. Therefore, the time t9-t from the leading edge of the vertical synchronization signal VSYNC signal ON for image formation until the end of image formation on the trailing edge of the paper.
Until y, the presence or absence of the paper cassette 408 or the presence or absence of paper in the paper cassette is not sensed. Also time 1. -1y to time t.

Until then, even if no paper or no paper cassette is detected, the RDY signal indicating that printing is possible is maintained true, and after time t9, the RDY signal is made false. The same applies to the printable display. In addition, there is no paper cassette when in manual paper feed mode.
Alternatively, even if there is no manual paper, the RDY signal remains true until image formation is completed.

Similarly, even if the paper cassette 408 is removed during image formation and a paper cassette of another paper size is inserted, the paper size is maintained from the leading edge of the VSYNC signal on until time t before the paper size is switched. , the paper size status is also set for the controller 202 to ensure the front paper size.

Similar to the processing when switching paper cassettes during image formation, even when switching paper feeding modes during image formation, the paper feeding mode and paper size before switching are guaranteed until the image formation is completed.

When a manual paper feeding command is output from the controller 202, the printer 401 enters manual paper feeding mode.

In the manual feed mode, if the print is possible as described above, the print signal PRN from the controller 202 is
T starts the print operation. If, as shown in Figure 6, the print signal PRNT signal is true and the printable conditions other than manual feed paper detection are in place, if paper is inserted into the manual feed slot, the printable conditions are in place and printing begins immediately. However, the printer's paper feeding operation
That is, the rotation of the paper feed roller 402 by the paper feed solenoid drive signal CPUD takes a time t from the completion of manually fed paper detection.
Do it after 10. Actually, the high voltage drive signal is HVTON, D
B.D.C.

) After the timing of making IVION true, CP
UD signal: becomes true. In the case of continuous printing by manual paper feeding, the paper feeding operation of the printer is performed tlo after manual paper detection is completed. Manual paper/Time from completion of detection tto
A certain timing during the elapse of is the vertical synchronization signal V of the previous page.
If the leading edge of SYNC on coincides with time t7, no post-processing of the print operation is performed and the CPU
Turn on the signal and proceed to print the next page.

In the case of cassette paper feeding, there is a universal cassette that allows you to freely set the paper size set in the paper cassette 408, and can also feed envelopes and other thick paper. Also, in manual paper feeding, the paper width of the manual paper guide 406 of the paper cassette 408 can be varied, allowing envelopes and other thick paper to be fed. When using this universal cassette paper feeding mode or manual paper feeding mode, the CPU 201
When printing the next page, the paper feed solenoid drive signal CPUD: true to vertical synchronization signal request signal VSREQ
: The time until the end is the time t when feeding paper from a normal cassette. Control is performed to further extend the time tw. The first case is ready for printing as shown in Figure 6.
When the paper feeding mode is universal cassette feeding or manual feeding, the print signal PRNT is sent from the controller 202.
Now is the time to print the first sheet. The second and subsequent sheets are the same as the normal cassette feeding mode. The second case is when the paper cassette 408 is switched to the universal cassette during printing in the normal cassette paper feeding mode, or when the controller 202 sends a command to switch the paper feeding mode to the manual paper feeding mode. At this time,
The CPU 201 displays the VS of the page before switching as shown in Figure 7.
From the leading edge of the YNC signal ON until time t7, neither the next print signal request nor the paper feeding operation is performed, and after the time t7 when the paper feeding mode is switched, the printing operation from the first sheet is controlled again.

The third case, as shown in FIG. 8, is when the printer is in a state where it can print by universal cassette paper feeding or manual paper feeding during post-print processing and receives the print signal PRNT from the controller. In the above three cases, the time required to print one sheet is longer than when feeding paper from a normal cassette.
This time tw is the time for the fuser to accumulate additional heat. When the printer displays insufficient toner or a paper jam occurs, the operator opens the upper door 1101. However, at this time, by opening the upper door 1101, the CPU 201
As mentioned above, the control program is reset once. In addition, the controller power ready signal CPR
If DY becomes false for a certain period of time, it is determined that the controller is down, and the control program of the CPU 201 is temporarily reset. However, when the upper door 1101 was opened, the printer had already experienced a malfunction in the fuser or polygon motor.
Alternatively, if a serious failure such as a beam detection signal detection failure has occurred, the control program maintains that failure mode without being reset. Also CPRD
If the aforementioned delay jam has already occurred in the printer when the Y signal becomes false for a certain period of time, the control program will not be reset (the paper jam mode will be maintained).The above control sequence is as shown in Figure 9. In step 901, if it is detected that the upper door 1101 is open, it is determined in step 902 whether or not a failure has occurred.The determination of failure is made when the failure occurs and the state is ready for printing. As soon as the signal RDY becomes false, in order to make the controller 202 recognize the failure, failure information is set in the status and since i<, the status is obtained by referring to the status.If it is a failure, control when opening the upper door is performed in step 911. and moves on to the next control.If there is no failure, perform reset preprocessing in step 905.If the upper door is not open in step 901, step 90
In step 3, determine whether the CPRDY signal has been false for a certain period of time,
If the controller is not down, move on to the next control. If the controller is down, it is determined in step 904 whether a delay jam has occurred. If a delay jam has not occurred, the process moves to step 905. There are two types of paper jams: the delayed jam described above and the retained jam. By setting flags according to the detection timing of each paper jam, it is possible to determine which type of paper jam is occurring. If there is a delay jam in step 904, the process moves to the next control.

In step 907, a failure determination is made again, and if it is a failure, in step 908, the failure status is set again and other processing is performed. In step 909, the paper jam is determined again, and if the paper is jammed, the jam status is set and other processing is performed again. Step 905
In the pre-reset processing, if there is information necessary after the reset, that information is set in the RAM area of the CPU 201,
Jump to the beginning of the control program in step 906,
Set by initializing the control program. Further, in the process during step 911 when the upper door is open, the fixing heater drive signal FSRD (hereinafter referred to as FSRD signal) is turned off so that the fixing heater H1 is not driven. Furthermore, in the fixing heater control process in step 912, even if the FSRD signal is off, the thermistor TH
The control maximum value T max of the temperature Tx of the fixing roller 411 based on the input of I is monitored. Therefore, the upper door 1101
This means that the temperature Tx of the fixing roller 411 continues to be monitored even during the opening.

FIG. 12 is a time chart showing the determination of activation and failure of the polygon motor M3.

When the 5CNON signal that starts the polygon motor M3 in response to the PRNT signal becomes true, the rotational speed of the polygon motor M3 increases. When the rotation speed approaches the specified rotation speed,
5CNRDY signal comes out.

When the polygon motor M3 locks in, it causes noching and the rotational speed fluctuates in the vicinity of the specified rotational speed, so the 5CNRDY signal becomes intermittent.

Let this hunting period be ta. CPU201 is 5C
tb longer than ta from the time the NRDY signal becomes true once
Wait time 5 Monitor the CNRDY signal.

When the 5CNRDY signal becomes completely true during this time tb, it is determined that the polygon motor M3 has reached the specified rotation speed, and the VSREQ signal is output.

If the polygon motor is hunting during the tb time, it is determined that the polygon motor M3 has not yet reached the specified rotation speed during the tb time, and monitoring of the next tb waiting time is started. If the CPU 201 does not determine that the specified rotation speed has been reached within the time tc after the 5CNON signal becomes true, it is determined that the polygon motor M3 is malfunctioning. When it is determined that the polygon motor M3 is malfunctioning, the paper that was previously fed by the paper feed roller is ejected out of the machine.

As described above, according to this embodiment, even when the drive of the paper conveyance system is interrupted due to a paper jam, the semicircular paper feed roller returns to its normal position, so even if the paper conveyance system is restarted after the paper jam is cleared, , the pulse motor, which is the drive motor, can be started up smoothly. Furthermore, since the paper feed roller is not in an incorrect position, it is possible to avoid double paper feeding at the time of startup of the paper transport system and at the time of a paper feed command during printing.

[Effects] As explained above, according to the present invention, the paper feeding operation can always be performed accurately.

[Brief explanation of the drawing]

Figure 1 is a control circuit diagram of the laser beam printer in this embodiment, Figure 2 is a relationship diagram between the low voltage power supply and printer controller, Figure 3 is a flowchart of the remaining toner amount detection method, and Figure 4 is a paper cassette and paper feed. Structure of the roller, Figure 5 is a timing chart for normal cassette paper feeding, Figures 6, 7, and 8 are timing charts for universal cassette paper feeding or manual paper feeding, and Figure 9 is for upper door oven. , a flowchart of part of the control method when the controller is down, Figure 1θ is a schematic diagram of the laser scanning system, Figure 11 is a diagram of the main body when the upper door is opened, Figure 12 is the determination of activation of polygon motor M3 FIG. 13 is a flowchart showing paper feed control and jam control in this embodiment. FIG. 14 is a flowchart showing cassette mode and manual feed mode in this embodiment. 202: Controller or host computer, 20
4: Pre-exposure lamp, 205: High pressure unit, 206: E
P cartridge, 207: Fixing heater drive circuit, 209
: Polygon motor control, drive circuit, 210: Laser drive circuit, 211: BD circuit, 212 Nigged array, 2
13: Reset circuit, R10O-R999: Resistor C10
0~C999: Capacitor, 5W100~5W399
: Switch, IC100~IC999: IC, PS2
00~PS299: Photo sensor, Hl: Fixing heater, THI: Thermistor, 5L201~5L202: Solenoid, TP200: Thermoswitch, Tri:) Liac, Q100-Q999: Transistor, Ml
, M3: Motor, LS201: Semiconductor laser, 40
1 Ni printer main body, 402: Paper feed roller, 406: Manual feed guide, 404 Ni registration roller, 40.5 Ni registration roller clutch, 407: Paper, 408: Paper feed cassette, 409: Paper sense lever, 41O: Feed Paper roller clutch, 411: Fixing roller, 1001: Polygon mirror, 1003: Collimator lens, 1004
Nijilintorical lens, 1005: Imaging lens, 1
006: Beam detection mirror, 1007: Reflection mirror, 1008: Photosensitive drum, 1009: Optical fiber, 1101: Upper door, 1102: Top for detecting sensitivity of photosensitive drum, 1103: 5W100 on/off lever. Patent applicant: Canon Co., Ltd. / η Akira Figure 10; Figure 1I-Figure

Claims (1)

[Claims] In a recording device in which the paper feeding operation by the paper feeding roller is performed by a paper conveyance drive device using a motor and is capable of detecting a paper jam, even if a paper jam is detected during the paper feeding operation, the paper feeding operation is not completed until the paper feeding operation is completed. A recording apparatus characterized by comprising a control means that does not stop the paper conveyance drive device.