JPH0665498B2 - Recording device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a recording device for recording image information, such as a laser beam printer or an ink jet printer, and more particularly to a signal from a generating means for generating a recording signal. The present invention relates to a recording device that can eject recording paper on a conveyance path.

[Prior Art] A laser beam printer that records an image by scanning a laser beam on a rotating drum with a rotary polygon mirror to form a latent image, developing the latent image, and transferring the latent image to a sheet is well known. belongs to.

FIG. 1 is a diagram showing an example of the configuration of a conventional laser beam printer, and a description thereof will be added below.

In FIG. 1, reference numeral 1 is a recording sheet that holds the recording sheet. 3 is one of the sheets 1 on the cassette of the recording sheet
A sheet feeding cam that separates only the sheet and conveys the leading end of the recording sheet 1 to the sheet feeding rollers 4 and 4'by a driving unit (not shown) is rotated intermittently for each sheet feeding.

Reference numeral 18 is a reflection type photo sensor, which detects the absence of paper by detecting the reflected light of the recording sheet 1 through a hole 19 formed at the bottom of the recording sheet cassette 2. When the sheet 1 is conveyed into the gap by the cam 3, the sheet feeding rollers 4 and 4'rotate while pressing the sheet 1 lightly to convey the sheet 1. The front end of the sheet 1 is the resist shutter 5
When the sheet arrives at, the sheet 1 is stopped from being conveyed by the resist shutter 5, but the sheet feeding rollers 4 and 4'slip and generate a conveying torque and continue to rotate. In this case, if the registration solenoid 6 is driven and the registration shutter 5 is released upward, the sheet 1 is sent to the conveying rollers 7, 7 '. The resist shutter 5 is driven by the laser beam 20.
Therefore, the image is printed at a constant timing with the image printed on the photosensitive drum 11.

After that, the carrying torque is obtained by the carrying rollers 7 and 7 '.
After passing through the fixing rollers 8 and 8 ', the paper is discharged by the paper discharging rollers 9 and 9'.

During this time, the image exposed on the photosensitive drum 11 is transferred onto the paper 1 by the cooperation of the cleaner 12, the charging device 13, the developing device 14, and the transfer charging device 15, is fixed, and is discharged.

Incidentally, in the figure, a is for regulating the conveyance direction of the sheet 1 by a guide. Reference numeral 16 is a paper feed table, and not only the first paper feed means from the paper cassette 2 but also the second paper feed means by manually feeding the sheets 1 one by one from the paper feed tray 16. Which enables the paper feed table 16
The paper sheet manually fed to the portion between the upper manual paper feed roller 17 and the manual paper feed roller 17 is lightly pressed by the manual paper feed roller 17 so that the leading edge of the sheet is registered like the paper feed rollers 4 and 4 '. The paper is conveyed until it reaches the shutter 5, where it makes a slip rotation. The subsequent transportation sequence is exactly the same as that for cassette feeding. The fixing roller 8 is the fixing heater 2
4 is accommodated and cooperates with a thermistor 23 that makes a slip contact with the roller surface to control the surface temperature of the fixing roller 8. Reference numeral 21 is a photo sensor that detects whether or not a sheet is present at the location of the resist shutter 5. A photo sensor 22 detects whether or not a sheet is present at the fixing rollers 8 and 8 '. Reference numeral 10 is a sheet stacker.

Such printers are generally not used alone,
It is connected to the controller with an interface cable, receives print commands and image signals from the controller,
The print sequence is performed.

Next, the signals transmitted and received by the above-mentioned interface cable will be briefly described below.

FIG. 2 is a diagram showing an interface signal between the printer and the controller. Each of the interface signals will be described below.

PPRDY signal: This signal informs the controller that the printer power is on.

CPRDY signal: This signal informs the printer that the controller power is on.

RDY signal: Printer sends PR from controller to be described later
When the NT signal is received, it is a signal indicating that the printing operation can be started or continued. For example, when the sheet cassette runs out of paper, it becomes FALSE.

PRNT signal: A signal for the controller to instruct the printer to start the printing operation, or to continue the printing operation when the printer is in the printing operation.

VSREQ signal ... RDY signal and PRNT signal are both TRU
E is a signal indicating that the printer is ready to receive the VSYNC signal described later.

VSYNC signal: This is a vertical (sub-scanning direction) synchronization signal for the printed image, and is a signal for the controller to make the printer synchronize the image on the drum with the paper.

BD signal: A horizontal (main scanning direction) synchronizing signal of a printed image, which is a signal indicating that the laser beam is at the starting point of main scanning.

VDO signal: Image signal to be printed by the controller, the printer outputs TRUE of this signal, the image is black, FALS
Print E as white.

SC signal: A bidirectional serial 8-bit signal that sends and receives COMMAND, which is a command signal from the controller to the printer, which will be described later, and STATUS, which is a status notification signal, which will be described later, that is sent from the printer to the controller. The SCLK signal described later is used.
Also, since it is a bidirectional signal, the SBS described later is used for input / output control.
The Y signal and the CBSY signal are used. COMMAND is a serial signal consisting of 8 bits, for example, a pause command for turning off only the fixing heater of the printer to keep it in an energy-saving state, a so-called pause state, and a pause release command for releasing the pause state and turning on the fixing heater, Further, it includes a cassette sheet feeding command for feeding sheets from the sheet cassette, a manual sheet feeding instruction for manually feeding sheets, and the like.

STATUS is a serial signal consisting of 8 bits. For example, the printer is in a wait state where the temperature of the fixing device has not reached the printable temperature, a jam has occurred, the sheet cassette is out of paper, or the printer is out of paper. Notify the status.

SCLK signal: This is a synchronizing pulse for the printer to fetch COMMAND or the controller to fetch STATUS.

SBSY signal ... Before the printer sends STATUS,
This is a signal for occupying the SC signal line and the SCLK signal line.

CBSY signal: This is a signal for occupying the SC signal line and the SCLK signal line before the controller transmits COMMAND.

GNRST signal: The controller initializes the printer status.

Next, the mutual operation between the printer unit and the controller unit will be described with reference to the system configuration diagram showing the connection configuration of the printer and the controller.

Now, assume that the power SW of the printer is turned on and the power SW of the controller is turned on. In this case, the printer initializes the internal state of the printer and then sends a PPRDY signal to the controller. Meanwhile, the controller sends the CPRDY signal to the printer after initializing the internal state of the controller. After that, the printer energizes the fixing heater 24 housed inside the fixing rollers 8 and 8 ', and when the surface temperature of the fixing rollers 8 and 8'reaches a fixable temperature, sends an RDY signal to the controller. .

After receiving the RDY signal, the controller sends a PRNT signal to the printer as needed for printing.
When the printer receives the PRNT signal, the photosensitive drum 11
To uniformly initialize the potential on the surface of the photosensitive drum, and at the same time, in the cassette feeding mode, the feeding cam 3
Is driven to convey the leading end of the sheet to the resist shutter 5. In the manual feed mode, the manually fed sheet is conveyed from the paper feed table 16 by the manual feed roller 17 to the registration shutter 15. When the printer is ready to accept the VDO signal, it sends a VSREQ signal to the controller.

After receiving the VSREQ signal, the controller sends a VSYNC signal to the printer. Upon receiving the VSYNC signal, the printer simultaneously drives the registration solenoid 6 to release the registration shutter 5. The controller is VSYN
After outputting the C signal, the BD signal transmitted from the printer is sequentially transmitted to the printer as an image signal VDO to be recorded as horizontal synchronization. The printer responds to the VDO signal
By blinking the laser beam, the photosensitive drum 11
A latent image is formed on the surface, the toner is attached by the developing device 14 to develop the latent image, then the developed image is transferred onto the paper by the transfer charger 15, and is fixed by the fixing rollers 8 and 8 ′ and discharged. To paper.

Next, when switching the paper feed mode of the printer to the cassette paper feed mode or the manual paper feed mode, the controller is
An 8-bit serial code corresponding to each paper feed mode is transmitted to the printer via a signal line in synchronization with the SCLK pulse signal. When the printer receives the cassette paper feed mode code, the manual paper feed roller 17 is not driven during printing, and the paper feed cam 3 is driven to switch the cassette to the paper feed mode.

On the other hand, when the printer receives the manual paper feed mode code, the paper feed cam 3 is not driven during printing and the manual paper feed roller 17 is driven to switch to a mode in which manual paper feed is possible.

When the power of the printer is turned on, the printer initializes the paper feed mode to the cassette paper feed mode.

GNRST is for initializing the printer in response to a command from the controller. When the same signal is received from the controller, the printer resets all jobs on the way and is reset to the state immediately after power-on. For example, when a plurality of printers are connected to the controller, this signal is used to bring all the connected printers into the same state.

In the configuration of the above-mentioned conventional example, generally, the printer and the controller generally send and receive the interface signal to each other through a connecting cable having a length of 1 m to several m. Therefore, the printer and the controller are not always placed adjacent to each other. Further, the printer and the controller usually have independent power switches.

Therefore, it is often possible that the printer mistakenly turns off the power switch of the controller during printing.

Conventionally, in this case, all signals including the PRNT signal from the controller become FALSE, so at the time the controller is powered off, the printer stops with sheets remaining in the middle of the paper transport path, and then the controller powers on. When the switch is turned on and printing is attempted again, the jammed paper causes a jam. Further, when the controller power is turned off, the controller side in the case described in the above example loses the memory of the paper feed mode instructed to the printer, whereas the printer side powers off the controller. Since the previous paper feed mode command is stored, when the power of the controller is turned on again, the paper feed mode may be different between the memory on the printer side and the memory on the controller side.

Furthermore, if the printer receives a GNRST signal from the controller and the printer is in the print state and the paper is being conveyed, the sheets that were being conveyed will remain in the middle of the paper being conveyed to the printer. When I tried to do so, I had trouble with Jiam.

[Problems to be Solved by the Invention] Therefore, in the above-described conventional technology, when the printer is temporarily powered off during sheet conveyance, or when a reset signal (GNRST) is input from a controller or the like, the jammed sheet causes jamming. May be judged. In such a case, there is a problem that printing cannot be performed unless the operator removes the accumulated sheets.

To solve this problem, it is conceivable to carry out the conveying operation only when the power is turned on or when the reset signal is input regardless of the presence / absence of accumulated sheets, but for a period of time during which accumulated sheets can be discharged. Even in such a case, there is a problem that a wasteful conveying operation is performed and the next image recording operation is delayed.

Moreover, by providing a detector for detecting the sheet on the conveyance path,
In order to carry out the conveying operation for discharging the sheet only when the staying sheet is detected, the detectors must be provided at a narrow interval on the sheet conveying path, resulting in a complicated structure and an increase in cost.

An object of the present invention is to solve the above-mentioned problems, and to start recording promptly without complicating the configuration unless sheets remain in the recording device when the recording device is turned on or when a reset signal is input. (EN) It is possible to provide a recording apparatus that can perform recording without fail by ejecting the accumulated sheet without the operator's hand even if the sheet is accumulated.

[Means for Solving the Problems] The above-described problems of the present invention include: a conveying unit that conveys a sheet along a conveying path; and a presence or absence of the sheet at the predetermined position provided on the conveying path. A detection unit, a recording unit that records an image on a sheet conveyed by the conveying unit, a drive of the conveying unit when the power is turned on or in response to an input of a reset signal, and the recording medium is stagnant on the conveying path. If the detection unit does not detect the sheet in a period shorter than the period required for discharging the sheet, the driving of the conveyance unit is stopped, and if the sheet is detected, the sheet is further discharged. And a control unit that drives the transport unit for a required period.

[Embodiment] Next, an embodiment of the present invention will be described in detail with reference to FIG. 3 and FIG.

FIG. 3 is a block diagram of the control unit of the printer and controller shown in FIG. 2. The ROM memory for storing the flow chart shown in FIG. 4, the RAM memory for storing various control data, and the input and output are controlled. One-chip microcomputer with built-in I / O port (hereafter, CPU
1). The CPU 1 is actually connected to the sheet conveying and discharging drive systems shown in FIG. 1 and each system for executing the electrophotographic process through the I / O port. Shows only the drive system of the seat and the input and output of signals of sensors provided in the drive system. On the other hand, the CPU 2 that controls the controller side is powered by
Only the N, OFF and RESET keys are shown. Both CPs
I / O buses 34 and 36 of U1 and U2 are connected to input / output interfaces (I / F) 30 and 32, respectively. The code signal output to the I / O bus is formed by the I / F as a signal corresponding to FIG. A signal line 38 connects the controller and the printer. Now, to further explain the procedure executed by the embodiment, A is the start of the program, and the program starts from here when the power is turned on. B is an initialization routine, which initializes the contents of the RAM. C is a main routine in which main operations such as a printing operation are performed. D is an interface signal with the controller. GNRST signal is T
R is a routine for determining whether or not it is TRUE, and E is a routine for similarly determining whether or not the CPRDY signal is TRUE.

K is a routine according to the present invention, and F is a routine for canceling the contents of the RAM storing the command received from the controller.

G is a routine for turning on the paper discharge motor, and simultaneously starts a timer for checking that one second has elapsed after the paper discharge motor for I was turned on. H is a photo sensor, 2
1 or 22 is a routine for detecting whether or not the presence of paper is detected, and J is a routine for driving the paper feed motor for another 10 seconds. L is a routine for stopping the driving of the paper feeding motor. After the routine K processing, jump to the start ruling A.

Next, the operation of the flow chart will be described.

Normally, when the printer is powered on, it goes through an initialization routine B, and then a MAIN routine C, a GNRST check routine D, and a CPRDY check routine E are circulated to perform print operations and the like.

At this time, if an initialization request such as generation of a power-on reset or pressing of an abnormal state release key (RESET) is generated, the GNRST signal from the controller becomes TRUE. Also,
GNRS that the power was cut off and the CPRDY signal became FALSE.
When detected by the T check routine D and the CPRDY check routine E, the circulation loop is skipped and jumped to the routine K.

In routine K, the contents of the RAM storing the command previously received from the controller in routine F are canceled. For example, if a manual paper feed mode command has been received from the controller before that, it is canceled and the contents of the RAM are rewritten to the same cassette paper feed mode immediately after power-on.

In the routines G, H, I, J, and L, the paper feed roller 4,
The CPU 1 gives a signal to a paper feeding motor (not shown) which simultaneously drives 4 ', the conveying rollers 7, 7'and the fixing rollers 8, 8', and drives them for 1 second. During this driving time, either the photo sensor 21 or the photo sensor 22 detects a sheet, and when a detection signal is given to the CPU 1, the CPU 1 further drives the paper discharge rollers 9 and 9'for 10 seconds thereafter, and the sheet that is staying in the meantime. Completely eject the paper. After that, jump to the start. At this time, the transport rollers 7, 7'for 1 second
If the photo sensor 21 or 22 does not detect a sheet even after driving, the carrying motor for driving the carrying rollers 7, 7'is stopped to jump to the start.

According to the above routine, GN which is an interface signal
When the RST signal becomes TRUE or the CPRDY signal becomes FALSE
If it becomes, the command contents up to that point are all canceled, and if there is stagnant paper, it is completely discharged and then jumped to the start.

It goes without saying that the routine K in the control flow of FIG. 4 may be executed in the initialization routine B.

As described above, according to the present invention, when the sheet is not detected by the detecting unit when the power is turned on or the reset signal is input, the conveying unit is driven so that the detecting unit does not detect the sheet. Even if the sheet stays at a possible position, the sheet can be surely detected by the detecting means.

At this time, a short driving time is sufficient for the conveying means for surely detecting the staying sheet by the detecting means, and when the sheet is not staying, a long-time conveying means such as discharging the sheet is required. Recording can be started quickly without driving. Further, when the detecting means detects a sheet during the driving of the conveying means for detecting the staying sheet, the conveying means is further moved for a predetermined time in order to discharge the sheet. The accumulated sheet can be surely discharged and recording can be performed without bothering.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a printer for explaining a conventional example of the present invention, FIG. 2 is a system configuration diagram showing signals between a printer and a controller, FIG. 3 is a block diagram showing a control unit of the printer and the controller, FIG. 4 is a flow chart showing a control flow according to the embodiment of the present invention. In the figure, 1 ... Sheet, 2 ... Paper feed cassette, 3 ...
... Paper feeding cam, 4 ... Paper feeding roller, 5 ... Registration shutter, 6 ... Registration solenoid, 7 ... Conveying roller, 8
...... Fixing roller, 9 ... Paper discharging roller, 11 ... Photosensitive drum.

Continuation of the front page (56) References JP-A-58-11446 (JP, A) JP-A-56-48345 (JP, A) JP-A-56-85762 (JP, A) Actual development 54-125650 (JP , U)

Claims (1)

[Claims] 1. A conveying means for conveying a sheet along a conveying path, a detecting means provided at a predetermined position on the conveying path for detecting the presence or absence of the sheet at the predetermined position, and a sheet conveyed by the conveying means. And a recording means for recording an image, and a period necessary to start driving of the conveying means at the time of turning on the power supply or in response to the input of a reset signal and to discharge a sheet stagnant on the conveying path. In a shorter period, when the detection unit does not detect a sheet, the driving of the conveyance unit is stopped, and when a sheet is detected, a control unit that drives the conveyance unit for a period necessary to further discharge the sheet, A recording device comprising: