JPH03218871A - Image forming apparatus - Google Patents

Abstract

PURPOSE:To shorten image processing time by removing and conveying a medium to be formed with an image, contained in containing means by conveying means when the warmup of image forming means is ended, and moving it to the vicinity of the forming means. CONSTITUTION:When the warmup of an image forming apparatus is ended, a cassette supply solenoid 309 is energized. When the solenoid 309 is energized, a feed roller 23 is rotated by one revolution. Accordingly, a sheet P is removed from a sheet cassette 22, and conveyed toward aligning roller pair 25. After predetermined time is elapsed, whether an aligning switch 48 is closed or not is checked, and if it is not closed, the fact that the sheet P is not yet arrived at the pair 25 is determined, it is processed as a sheet jam, an operator call status is set, a ready signal PRDY0 is output, a print request is set in a data bus D0-D7, an attention signal ATN1 is output, and a print ready state is set.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to an image forming apparatus such as a laser printer.

(Prior Art) Conventionally, image formation in an image forming apparatus such as a laser printer is performed through various steps such as charging, exposure, development, transfer, peeling, cleaning, and fixing. In such an image forming apparatus, a charging device, an exposure device, a developing device, a transfer device, a peeling device, a cleaning device, etc. are sequentially arranged around the photoreceptor, and a fixing device is further provided to receive paper from the peeling device. By driving each of the above-mentioned devices according to the rotational movement of the paper, each of the above-mentioned image forming steps is executed, and an image is formed on the paper.

In such a laser printer, the control system includes an engine control section that controls the above-mentioned devices to complete each of the image forming steps, and a printer control circuit that controls the operation of the engine control section. The engine control section and the printer control section are connected by sending and receiving commands and status.

For this reason, the paper conveyance process from the paper feed cassette or the transmission/reception of the -J7 command and status between the engine control unit and the printer control unit is started, so if the image processing time of the printer control unit is long, Even if the engine control section is in a standby (preparation complete) state, the engine control section is always forced to wait until the end of the process, so no consideration has been given to shortening the processing time for paper conveyance processing.

(Problems to be Solved by the Invention) As described above, even if the first control means for controlling the image forming means is in the ready state, the image data for forming an image by the image forming means is This was done in order to solve the disadvantage that the moving process of the image forming medium is started after the process of the second control means that generates the image is completed, so the moving process takes a long time and the image processing time is taken. When the preparation of the first control means for controlling the image forming means is completed, the image forming medium is moved to the front of the image forming means, and the image data for forming the image by the image forming means is transferred. By waiting for the image data to be generated from the second control means, even if the processing time in the second control means is long, the image forming medium is moved in advance, so the time required for the movement is reduced. An object of the present invention is to provide an image forming apparatus that can shorten image processing time.

[Structure of the Invention] (Means for Solving the Problems) An image forming apparatus of the present invention includes an image forming means for forming an image on an image forming medium, a storage means in which the image forming medium is stored, and a storage means for storing the image forming medium. a conveying means for taking out an image forming medium stored in the means and feeding it to the image forming means; a warming-up means for performing a warming-up process for the image forming means; and a warming-up means for completing the warming-up of the image forming means. At this time, the image forming apparatus includes a processing means for moving the image forming medium to a position near the image forming means by taking out the image forming medium from the storing means and transporting the image forming medium using the conveying means.

(Function) In the present invention, when the image forming means has finished warming up, the image forming medium stored in the storage means is taken out and conveyed by the conveying means, so that the image forming medium is brought to the vicinity of the position of the image forming means. This allows the medium to be moved.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIGS. 1 and 2 show the configuration of an image forming apparatus according to the present invention, for example, an image forming unit apparatus including a laser printer with optional equipment.

That is, the image forming unit device includes a multi-cassette feeder 2 that feeds paper (plain paper) P of a predetermined thickness such as cut paper as an image forming medium into the printer 1, and a multi-cassette feeder 2 that feeds paper (plain paper) P of a predetermined thickness such as cut paper as an image forming medium, and a multi-cassette feeder 2 that feeds paper (plain paper) P of a predetermined thickness such as cut paper as an image forming medium, The laser printer includes optional equipment such as an envelope feeder 3 that feeds paper (cardboard) A that is thicker than plain paper into the printer 1, and a jogger 4 that serves as a sorting device that sorts paper P or paper A after image formation into predetermined numbers. 1 and configured. The multi-cassette feeder 2, envelope feeder 3, and jogger 4 are connected online to a control section (not shown) in the main body of the laser printer 1. An operation panel 100 is provided on the upper surface of the laser printer 1.

Further, inside the laser printer 1, a laser optical system 12, a photosensitive drum 17, a charging device 18, a developing device 19, a transfer device 20, a static eliminator 21, a peeling device 35, a fixing device 37,
In addition to the process system such as the cleaning device 45, there is also a paper feed cassette 22, a delivery port-ra 23, and an aligning roller pair 25.
, conveyor belt 36, gate 38, paper ejection roller pair 39, 4
2 etc. are provided. The laser optical system 12 includes a semiconductor laser oscillator (not shown) that generates laser light;
A collimator lens (not shown) that corrects the laser light from this oscillator to eastward light, and a polygon mirror as a rotating body that has a portion of an octahedral mirror that reflects the laser light from this lens for each scanning line. (rotating mirror) 13
, f/θ lens 14, mirrors 15 and 16, and a mirror motor 60 that rotates (drives) the polygon mirror 13.
It is composed of.

During the image forming operation, the laser light from the laser optical system 12 corresponding to an image signal from an external device (not shown) or the operation panel 100 is transmitted to the photoreceptor drum l7.
imaged on the surface of The photosensitive tram 17 rotates in the direction of the arrow shown in the figure, and the surface thereof is first charged by a charging device 18, and then exposed by a laser optical system 12 in accordance with an image signal. That is, as the polygon mirror 13 is rotated by the mirror motor 60, the laser beam generated from the semiconductor laser oscillator moves from the left to the right of the photosensitive drum l7 (from the front side to the back side in FIG. 6) at a constant speed. An electrostatic latent image is formed on the surface. This electrostatic latent image is made visible by applying toner by the developing device 19.

On the other hand, the sheets P as the image forming medium of the sheet feed cassette 22 are taken out one by one at the delivery port-ra 23, and are taken out from the sheet guide path 2.
4, and is guided to a pair of aligning rollers 25, and sent to a transfer section by this pair of rollers 25.

In addition, sheets of paper that are taken out one by one from the paper feed cassette 30 in the multi-cassette feeder 2 through the feed port roller 32 and guided to the aligning roller pair 25 through the paper guide paths 34 and 29 are delivered to the transfer section. P or paper cassette 3l
The sheets are taken out one by one at the paper feed port-ra 33 and sent to the paper guide path 3.
The paper P1 is guided to the pair of aligning rollers 25 through the paper guide paths 28 and 29, or the paper P1 is taken out one by one from the stacker 26 in the envelope feeder 3 by the delivery roller 27 and passed through the paper guide paths 28 and 29 to the pair of aligning rollers 25.
In addition, the paper A1 guided to the paper sheet P fed from the manual paper feed section 44 and guided to the pair of aligning rollers 25 through the paper guide path 29, or the paper P fed from the manual paper feed section 44 and guided to the pair of aligning rollers 25 according to the specification from the external device or the operation panel 100. It is designed to be sent by

Then, the paper P or paper A sent to the transfer section is brought into close contact with the surface of the photoreceptor drum 17 at the transfer device 20, and the toner image on the photoreceptor drum 17 is transferred by the action of the transfer device 20. . This transferred paper P or paper A is peeled off from the photosensitive drum 17 by the action of a peeling device 35, and is sent to a fixing device 37 by a conveyor belt 36, where it passes through a heat roller that generates heat for fixing. 37, the transferred image is thermally fixed. This heat roller 371 has a built-in heater lamp 37a for heating. After fixing, the paper P or paper A passes through a gate 38 and is delivered to the paper ejection tray 4 by a pair of paper ejection rollers 39.
0 or the upper conveying path 4 by the gate 38
1, and the paper is sent to the paper discharger 4 by a pair of paper discharge rollers 42.
The paper is discharged onto a paper discharge tray 43 which is movably supported by the paper.

Further, the photosensitive drum 17 after the transfer is cleaned by a cleaning device 4.
After the residual toner is removed by step 5, the residual image is erased by the static eliminator 21, thereby making it possible to perform the next image forming operation.

Note that the fixing device 37 is formed into a unit (user unit), and is configured to be able to be attached to and detached from the printer 1 independently. Also, in front of the pair of aligning rollers 25, there is an aligning switch 48 for detecting a paper feeding error to the transfer section by the pair of aligning rollers 25, etc., and in front of the pair of paper ejecting rollers 39, 42, , paper ejection switches 49, 49 are provided for detecting paper ejection errors caused by the paper ejection roller pairs 39, 42, respectively.

In addition, the paper feed cassettes 22, 30, and 3I have paper P
Paper detectors 50, 51, and 52 are arranged to detect the presence or absence of paper P in the paper feed cassettes 22, 30, and 3l, respectively.

Further, above the laser optical system 12, there is an engine control board equipped with an engine control circuit 70 that controls each electrical device provided in the apparatus main body 1 to control operations for completing the electrophotographic process. A board on which a printer control circuit 7l for controlling the operation of the engine control circuit 70 is mounted is also arranged.

Up to three boards for the printer control circuit 71 can be installed depending on the degree of function addition (for example, adding types of fonts, kanji, etc.). Further functions can be added by inserting function-adding IC cards 517 into three IC card connectors 72 arranged on the front edge of the circuit board 71. Furthermore, a connector (not shown) for connecting to a host device 409 (described later), which is an external output device such as a computer or word processor, is provided on the left end surface of the board of the printer control circuit 7l located at the bottom. There is.

As shown in FIG. 3, the operation panel 100 has a number of panels,
Liquid crystal display 100 that displays modes, guidance messages, etc.
a. LED display 10 that lights up and displays various statuses with LEDs
0b, and a switch 100c for instructing various operations. The LED display 100b indicates whether or not it is connected to an external device, that is, the online/offline mode. "Ready" indicates that the device main body 1 is ready for operation. ``Data'' indicates, ``Operator'' requests an operator call, ``Service'' requests a service call, and ``Mode'' indicates auto/manual.

The switch 100C includes, for example, a menu key, a value key, a numeric keypad (not shown), or the like. The menu key is composed of two keys, "Next item" and "Previous item", and is displayed on the liquid crystal display 100.
The multiple menu information displayed on the left half of a is incremented each time the "Next item" key is pressed, and decremented each time the "Previous item" key is pressed, and these display operations are cyclical. It's about to be repeated. In addition, the value keys above are also “Next item” and “
It consists of two keys for "previous item", and the LCD display 10
A plurality of value information corresponding to the menu information displayed on the left half of 0a are incremented each time the "next item" key is pressed, and decremented each time the "previous item" key is pressed, and are displayed on the liquid crystal display 100a. displayed on the right half,
These display operations are cyclically repeated.

The operator selects and instructs a desired operation by operating the menu keys and value keys.

Next, the configuration of the engine control section will be explained.

FIG. 4 is a block diagram showing the configuration of main parts of the engine control section 300. In the figure, 302 is a power supply device;
By turning on the main switch 301, +5v and +24y power supply voltages are output. The power supply voltage of +5V is supplied to the engine control circuit 70, and is further supplied to the printer control circuit 7 via this engine control circuit 70.
Supplied to I.

On the other hand, the +24V power supply voltage is connected to the cover switches 303 and 30.
4 is sequentially supplied to the engine control circuit 70. Then, the power is supplied to the scanner control circuit 101, the high voltage power supply 305, and the mechanism drive circuit 306 via the engine control circuit 70, respectively. Then, from the scanner control circuit 101, a semiconductor laser 90 and a mirror motor 92 are connected.
From the mechanism drive circuit 306, the pre-exposure device 21, main motor 307, manual paper feed solenoid 308, cassette paper feed solenoid 309, aligning solenoid 31
0, toner supply solenoid 31l1 and cooling fan 50
0 etc., and is used as a driving power source for these.

Further, the power supply device 302 is provided with a zero-cross switch type heater lamp drive circuit (not shown) consisting of, for example, a phototriac coupler and a triac, which drives the heater lamp 501 inside the fixing device 33. The above +24V is used as a driving power source for the light emitting side LED of the atk coupler. In the heater lamp drive circuit with this configuration (well, as is well known, when the light-emitting side LED is turned on/off, the light-emitting side phototriax is turned on/off at the zero cross point of the AC power supply, so that the next stage main By turning on/off a triac, which is a switching element, the AC power source S1 is energized or cut off to the heater lamp 37a.
A heater control signal S2 for turning on/off D is supplied from the engine control circuit 70 to the power supply device 302, and a thermistor 37b provided in the fixing device 37
The detected temperature signal is supplied to the engine control circuit 70.

Further, the cover switch 303 is turned off when a door (not shown) is rotated upward, and the cover switch 304 (not shown) is turned off when opened. Therefore, when the top cover or rear force bar is open, switch 303,
304 cuts off +24V, the operations of the semiconductor laser 90, mirror motor 60, high voltage power supply 305, main motor 307, solenoids 308 to 311, cooling fan 500, heater lamp 37a, etc. are stopped, allowing the operator to Even if the inside of the main body 1 is touched, there will be no problem.

FIG. 5 is a block diagram showing the configuration of the engine control circuit 70. In the figure, the CPU 350 is the engine control unit 3
It controls the entire ROM 351 and operates according to a control program stored in the ROM 351. The RAM 352 is used as a working buffer for the CPU 35. E2PROM353
The total number of prints, etc. are stored in the . The printer interface circuit 354 mediates the exchange of the interface signal S3 with the printer control circuit 71. Laser modulation control circuit 3
55 controls the semiconductor laser 90 to be forced to turn on periodically in order to generate a laser light detection signal S4, which will be described later, and also performs control according to the image data sent from the printer control circuit 7 using the interface signal S3. It modulates and controls the semiconductor laser 90 and outputs a laser modulation signal S5 to the scanner control circuit 101.

The output register 356 receives control signals S6, S7, and S that respectively control the mechanical part drive circuit 306, the high voltage power supply 305, the scanner control circuit 101, and the above-mentioned heater lamp drive circuit.
8, S2 is output. The voltage signals S9 and S10 generated by the thermistor 37b and the toner sensor 324 are input to the A/D converter 357, and these voltage values are converted into digital values. The input register 358 receives status signals S11, S12 from the paper empty switch 320, the manual feed switch 32l1, the paper discharge switches 49, 49, the mounting switch 323, the aligning switch 48, and the paper detectors 50, 51, 52, 53. , S13, S14, S15,
Sl7 and +24■ on/off status signal 81B
is entered. In addition, the internal bus 359 is
PU350, ROM351, RAki352
, E2PROM 353 , printer interface circuit 354 , laser modulation control circuit 355 , output register 35
B, the A/D converter 357, and the input register 358 exchange data with each other.

The mechanism drive circuit 306 is provided with a drive circuit for driving various motors, solenoids, etc., and receives a binary control signal S output from the output register 356.
6 controls on/off. That is, for example, each drive circuit is turned on when it is "1" and turned off when it is "0".
+24y is energized or cut off to the pre-exposure device 21, main motor 307, solenoids 308 to 311, and cooling fan 500. The scanner control circuit 101 is provided with a drive circuit for a semiconductor laser 90 and a mirror motor 60. The semiconductor laser 90 is turned on/off by a laser modulation signal S5 output from the laser modulation control circuit 355, and the Miramotor 60 is controlled by a control signal S8 output from the output register 356.
On/off is controlled by. Further, a PIN diode is used in the laser light detection sensor 312, and when the laser light a passes through the laser light detection sensor 312, a current proportional to the light energy flows. This current signal is sent to the laser modulation control circuit 355 as a laser light detection signal S4.

Further, from the high voltage power supply 305, a developing bias power supply section (
), the charging device 18 , and the wire high-voltage power supply section (not shown) of the transfer device 20 , respectively.
0, charging S22, and transfer S24 high voltage signals are output. These ON and OFF states are controlled by 1 and 0 of the control signal S7 output from the output register 356.

As described above, within the engine control unit 300, power is supplied to each electric circuit via the engine control circuit 70, and each part is controlled by a binary control signal output from the engine control circuit 70. It has become. This engine control section 300 and a printer control section 400, which will be described later, are connected by an interface signal S3.

Next, the configuration of printer control section 400 will be explained.

FIG. 6 is a block diagram showing the configuration of the main parts of the printer control section 400. In the figure, a CPU 401 controls the printer control unit 400 as a whole.

The ROM 402 stores a control program, and the CPU 401 operates according to this program. The ROM 402 also stores data related to the paper P such as a password to be checked when changing data, a top margin, a left margin, a beta live, message information to notify the operator, and the like. The RAM 403 is used as a page buffer for temporarily storing image data sent from the host device 409. When the image data sent from the host device 409 is a large amount of data such as bitmap data, the extended memory 404 is
The M403 is a large capacity memory used when it is not possible to store one page of data. Video RAM405
The image data developed into a bit image is stored, and this output is sent to the serial-parallel conversion circuit 406.
is being supplied to. The serial-to-parallel conversion circuit 406 converts the image data developed into a bit image in the video RAM 405 and sent as parallel data into serial data, and sends the serial data to the engine control circuit 70.

The host interface 408 is used to exchange data between the printer control unit 400 and a host device 409, which may be a computer or an image reading device, for example, and has two types: a serial transfer line 410a and a parallel transfer line 410b. We are prepared.

Then, it can be used appropriately depending on the type of data transferred to and from the host device 409. The engine interface 411 mediates the exchange of an interface signal S3 between the printer control circuit 71 and the engine control circuit 70. Connection circuit 4
Reference numeral 13 indicates an I
The power supply and signal line supplied to the IC card 517 are cut off to prevent data stored in the IC card 517 from being destroyed due to noise generated during insertion and removal.

The operation panel control circuit 407 controls displaying a guidance message on the liquid crystal display 100a of the operation panel 100;
The CPU 4 controls the lighting, extinguishing, and blinking of the LED display 100b, or controls the data input from the switch 100C.
This is used to control the transmission to 01. Further, the internal bus 412 connects the CPU 401, ROM 402, RA
M403, expansion memory 404, video RAM 405,
Operation panel control circuit 4ro 7, host interface 40
8, engine interface 411, and connection circuit 4
This is a bus that exchanges data with the 13.

Further, the IC card 517 is a non-volatile memory, for example, a static RAMSE2P with battery backup.
It is composed of ROM, EPROM, mask ROM, etc. These IC cards 517 store, for example, character fonts, emulation programs, and the like.

Next, the configuration of the interface signal S3 will be explained.

FIG. 7 shows each signal of the interface signal S3. In the figure, DO-D7 is an engine control circuit 70
It is a bidirectional data node that transmits status from the printer control circuit 71 to the printer control circuit 71 and commands from the printer control circuit 71 to the engine control circuit 70, and is used by switching between the status and command at the timing shown in FIG. It has become so. That is, the engine control circuit 70
When the busy signal BSYO output from the printer is at a high level (not busy), when the hash direction signal DIR is set to a low level, the Do-D7 is switched to the direction of transmitting a signal from the engine control circuit 70 to the printer control circuit 71. The status is output on DO-D7. This allows the printer control circuit 71 to read the status.

On the other hand, when the printer control circuit 71 sends a command, if the bus direction signal DIR is set to a high level when the busy signal BSYO is at a high level (not busy), the DO-D7 is sent from the printer control circuit 71 to the engine control circuit 7RO. The direction is switched to transmit a signal and a command is output on the DODT. When the strobe signal STBO is set to low level in this state, the engine control circuit 70 reads the command on DO-D7 while the strobe signal STBO is low level, and the busy signal BSYO is set to low level (
busy). In this busy state, the engine control circuit 70 performs processing such as command analysis. When the busy signal BSYO is set to a low level, the printer control circuit 7l returns the strobe signal STBO to a high level and finishes sending the command. When the command processing in the engine control circuit 70 is completed, the busy signal BS
YO is returned to high level again.

Note that commands sent while the busy signal BSYO is at a low level are not received by the engine control circuit 70. Furthermore, the status on the data path DO-D7 does not change immediately when a state change occurs in the engine control unit 300, but is updated only when the status is returned in response to a command received after the state change. There is.

The attention signal ATN1 is output when the basic status on the print sequence between the engine control circuit 70 and the printer control circuit 71 changes, and is output when the basic status of the print sequence between the engine control circuit 70 and the printer control circuit 71 changes.
When it becomes possible to receive a SYNC command and when one page of image data has been received, it is set to a high level, and when an attention reset command is received, it is reset to a low level. When the attention signal ATN1 changes from a low level to a high level, the printer control circuit 71 sends an attention reset command to the data path Do-D7 to reset the attention signal ATN1, and then the data path DO-D7.
It is now possible to read the status on D7 and find out the changed basic status. In addition, the above basic status is also output on the data path by the basic status request command that requests the basic status, so the content of the changed basic status can be known by the basic status request command prior to the above attention reset command. It is now possible to do this.

The ready signal PRDYO indicates that the engine control unit 300 is in a ready state when it is at a low level, and indicates that the engine control unit 300 is in a ready state when it is at a high level.When this signal is at a low level, a printing operation by the engine control unit 300 is possible. It is.

The system clear signal SCLRI is the printer control circuit 71
200~ after +5V rises with the reset signal of
The level remains high for 500 msec, during which the printer control circuit 7l enters the reset state.

The prime signal PRIMEO is a reset signal to the engine control circuit 70. While this signal is at a low level, the busy signal SYO is at a low level, the ready signal PRDYO is at a high level, and the engine control circuit 70 is set to a predetermined initial state. return.

The horizontal synchronization signal HSYNCO is a signal generated every time one line is scanned by the laser exposure unit 22.
The number of lines corresponding to the effective print length in the transport direction of the paper P after receiving the NC command is output in synchronization with the laser light detection signal S4.

The video clock VCLKO is the horizontal synchronization signal HSY
This is a synchronization clock for inputting one line of video data (image data) VDO to the engine control circuit 70 following the NCO, and is output in numbers corresponding to the effective print width of the paper P in the horizontal scanning direction. Then, the video data VDO is taken into the engine control circuit 70 in synchronization with the falling edge of the video clock VCLKO.

In accordance with this video data VDO, the laser exposure unit 22 performs exposure scanning on the photoreceptor drum 17 to form a latent image on the photoreceptor drum 17. In addition,
When the video data VDO is at a low level, it is visualized on the paper P as a dot image.

Next, in the above configuration, FIGS. 9(a) to (e)
) and the timing chart shown in FIG. 10, the operation of the engine control section 300 of the laser printer will be described.

First, when main switch 3 (11) is turned on, +5V
A reset signal (not shown) is generated in synchronization with the rise of the power supply, and the engine control circuit 70 enters a reset state. Further, in response to this reset signal, a reset signal SCLRI (see FIG. 7) is output to the printer control circuit 71, and the printer control circuit 7l is also reset. Then, after the +5V power supply is turned on, 200~5
After 00 msec, the value of the reset signal is inverted, the reset state is released, and the CPU 350 starts executing the program stored in the ROM 351.

That is, first, data such as RAM 352 is initialized (step ST50). Next, the status of each switch is read into the input register 35B to prevent paper jams and
It is checked whether an operator call state such as a cover open, a process unit not installed, or a paver empty state has occurred (step ST51). here,
If an operator call is occurring, it is checked whether only paper empty is occurring (step ST52), and if an operator call other than vapor empty is occurring, the process returns to step ST51 and the operator call state is canceled. wait for it to happen. On the other hand, when only paper empty occurs in step ST52,
Alternatively, when an operator call is not generated in step ST51, heating of the fixing device 37 is started (step ST53). Next, to initialize the electrophotographic process, the main motor 307 and pre-exposure device 21 are turned on (step ST54), and then charging S22 is turned on sequentially at time intervals determined by the program (step ST54). Step ST55), and the developing bias S20 is turned on (step ST56).

In this state, it is checked whether a certain period of time (approximately 30 seconds) has elapsed (step ST57), and until the certain period of time has elapsed, it is checked whether or not a cover oven has occurred (step ST90). . Then, when the cover oven occurs, the above steps ST53 to S
Each output turned on at T56 is turned off (step ST91
), the process returns to step ST51. On the other hand, step ST
When it is confirmed in step 57 that a certain period of time has elapsed, the charging S22 is turned off (step ST58), and then the developing bias S20 is turned off in sequence at the timing determined by the program (step ST59), and the main motor 307,
And the pre-exposure device 2l is turned off (step ST60).
. The warm-up operation of the image forming apparatus is completed through the series of operations from steps S753 to S60.

Next, the cassette paper feed solenoid 309 is turned on (step S600). Here, cassette paper feed solenoid 3
09 is on, the feed roller 23 rotates once, and the paper P is taken out from the paper feed cassette 22 and conveyed toward the aligning roller pair 25. Then, after a certain period of time has passed since the paper P was fed,
It is checked whether or not the aligning switch 48 is on (step S602). If the aligning switch 48 is not on, it is determined that the paper P has not reached the pair of aligning rollers 25, and the paper is jammed. Handled as operator call status (jam)
is set, and the ready signal PRDYO is also set to 1 (step S96).

Then, the ready signal PRDYO is output (changed from high level to low level), a print request is set to the data path DO-D7, and the attention signal ATN1 is output (changed from low level to high level).
The fixing device 37, which has started heating in step ST53, has reached a temperature sufficient for the fixing operation in the process leading to step ST61.

Furthermore, when an operator call occurs, its contents are output on the data path as an operator call status.

On the other hand, in the state of step ST61, the printer control circuit 7
l can recognize the print request by sending the above-mentioned attention reset command to reset the attention signal ATN1 to a low level, and then reading the status on the data path in the above-described procedure. In FIGS. 9(a) to (e), this attention reset command and the reset of the attention signal ATNI (
The process of changing from a high level to a low level) and the operation of printing the second sheet are omitted.

Next, it is checked whether a print command has been received (step ST62). When a print command is not received, it is checked whether an operator call has occurred (ST92), and when an operator call has occurred, the print request is canceled and the operator call status is set. At the same time, the ready signal PRDYO is set to high level (
Step ST94). Then, it is checked whether or not a cover open occurred among the causes of the operator call (
In step ST95), if an opening has occurred, the process returns to step ST51. On the other hand, when the cover oven is not occurring, the process returns to ST92 and waits for the operator call to be released. In step ST92, if no operator call has occurred, it is checked whether the ready signal PRDYO is at a low level (step ST93), and if this signal is at a low level, the process returns to step ST62 and a print command is issued. When the level is high, it is already in the not-ready state in step ST94, so the process returns to step ST61 and the ready state is returned again. That is, the above step ST62-
The flow of ST92-ST93-ST62 is a state of waiting for a print command, a so-called standby state.

When it is determined in step ST62 that a print command has been received, the print request is reset and a series of print operations are performed.In other words, as shown in FIG. 10, first, the mirror motor 60 is turned on (step ST6B), then the main motor 307 and the pre-exposure device 21 are turned on at predetermined time intervals (step ST64), the charging S22 is turned on, and the developing bias S20 is turned on (steps ST65 and ST66).
).

Further, each device that was turned on in the process from step ST63 to step ST66 is turned off in sequence at a timing determined by the program (step ST97), and the process returns to step ST92 to wait for the jam to be cleared. Next, the VSYNC request is set, and the attention signal ATNI is output (changed from low level to high level) (ST69).

Then, it is checked whether or not the VSYNC command has been received (step ST70), and if it is received, the VSYNC command is received.
The NC request is reset, data transfer in progress is set, and laser exposure is started. That is,
The horizontal synchronization signal HSYNCO and video output V
While transmitting CLKO, reception of the video data VDO is started, and an image pattern based on the video data VDO is exposed on the photosensitive drum l7 (ST7 1).
.

Note that until step ST71, the pair of aligning rollers 25 remains stopped, so the paper P stops when its leading edge reaches the pair of aligning rollers 25. Therefore, after a certain period of time has elapsed, the aligning solenoid 310 is turned on (step ST
72) As a result, the aligning roller pair 25 begins to rotate and the paper P is conveyed toward the transfer device 20. Note that the aligning solenoid 310 is
It is turned on at a timing such that the leading edge of the image on the photosensitive drum l7, which has started exposure in step ST71, coincides with the leading edge of the paper P. Then, the leading edge of the paper P is -transfer device 20
The transfer S24 is turned on at the timing of reaching (
Step ST73). Paper P transported in this way
, the toner image formed on the photosensitive drum 17 by the developing device 19 is transferred by the transfer device 20.

Furthermore, when the rear end of the paper P completely passes through the paper feed cassette 22, the next paper P is automatically fed, a print request for the second paper P is set, and an attention signal ATN 1 is output. (changes from low level to high level) (step ST74). On the other hand, after a certain period of time has elapsed since the paper P was conveyed from the pair of aligning rollers 25, it is checked whether or not the paper ejection switch 49 is on (step ST75), and if it is not on, the leading edge of the paper P is It is determined that the print request has not reached the paper discharge roller unit 42, the print request is reset, the operator call status (jam) is set, and the ready signal PRDYO is set to 1 (step ST98). Then, each device that has been turned on up to step ST74 is turned off in sequence (step ST99).
, return to step ST92. On the other hand, if the paper ejection switch 49 is on, the process waits until one page of the image data started to be received in step ST71 is captured (step ST76). When the reception of the image data is completed, the data transfer status is reset and the attention signal ATN1 is output (changed from low level to high level) (step ST77). Next, the aligning solenoid 310 is turned off at the timing when the trailing edge of the paper P passes the aligning roller pair 25 (step ST
78), the aligning roller pair 25 stops. Furthermore, the transfer S24 is turned off at the timing when the trailing edge of the paper P passes the transfer device 20 (step ST79). Next, after a certain period of time has passed since the aligning solenoid 310 was turned off, it is checked whether the paper ejection switch 49 is turned off (step ST80). If it is not turned off, it is determined that the trailing edge of the paper P has not passed the paper ejection roller unit 42, and the step ST9
The process branches to step 8 and jam processing is performed. On the other hand, when the switch is off, it is determined that the paper P is being ejected normally, the paper conveying status is reset, the charging S22 is turned off (step ST82), and the developing high-usage S20 is turned off. (step S183), the mirror motor 60 is turned off (step ST84), and the pre-exposure device 21 and main motor 307 are turned off (step ST85), completing a series of printing operations and returning to step ST62 again to enter the standby state. become.

Next, the printer control circuit 40 according to the above data transfer procedure
The operation of 0 will be explained with reference to the flowchart in FIG.

For example, if your laser printer is offline and
When the PU 401 determines that it is in an offline state (step ST1), the host device 40
It is checked whether the printing process for the data received from 9 has been completed (step ST2), and if it has not been completed, the process branches to step ST12 to continue the printing process.

On the other hand, if the printing process is completed, the above step STI
, ST2 are repeatedly executed to create an idling state and wait for the laser printer to be placed on-line.

When the laser printer is brought online in such a state, it is checked whether the data sent from the host device 409 is a command (step ST3), and if it is a command, it performs the operation corresponding to the command. (Step ST4) If it is not a command, execution of the above command is skipped and the process proceeds to step ST5. The above commands, for example, define the attributes of the following data or control the printer without sending or receiving data. Next, it is checked whether the page buffer provided in the RAM 403 as a buffer for data reception is full (step ST5), and if it is not full, the data sent from the host device 409 is used as an image. It is checked whether it is data or not (step ST6). If it is not image data, the process returns to step STI and waits for command or image data to be received by repeating the above series of steps. In such a state,
When it is determined in step ST6 that image data has been received, the received image data is sequentially stored in the page buffer (step ST7). Next, it is checked whether storage for one page has been completed (step ST8).
, if not completed, the "data" lamp of the LED display too b provided on the operation panel 100 starts blinking (step STIO). Next, step S
By returning to TI and executing the above series of steps, it waits until one page's worth of image data is accumulated in the page buffer. When it is determined that one page of image data has been stored by repeatedly executing the above series of steps, the "data" lamp is turned off (step ST
9) End the data reception process. And step S
The process moves to print processing after T12. Note that if it is determined in step ST5 that the page buffer is full, the data reception operation is stopped (step STII).
), in this case as well, the process moves to the print processing after step ST12. In this way, during the data reception operation, the above-mentioned "Data 1 lamp" is blinked to notify the operator.

Next, when storing one page of image data in the page buffer is completed, it is checked whether the scan buffer provided on the video RAM 405 is full (step ST12). Here, if it is determined that the scan buffer sofa is not full, the CPU 401 converts it into the image data of the character image stored in the page buffer, and stores the image data as the video RAM 4 as a scan buffer.
05 (step ST13). On the other hand, if the scan buffer is full, step STI 3
is skipped.

Next, it is checked whether the print command has already been sent (step ST14), and if it has been sent, the following print command sending process (steps ST15, S
T19) is skipped and the process proceeds to step ST20. On the other hand, if the print request has not been sent, it is checked whether a print request has been sent (step ST15). At this point, if it is determined that no print request has been made,
It is determined that the print preparation on the engine side is not completed,
The process returns to step STI and re-executes the above series of steps to wait for a print request to be issued.

On the other hand, if it is determined that a print request has been issued, a print command is sent (step ST1).
9). Next, it is checked whether the VSYNC command has already been sent or not (step ST20). And VS
When it is determined that the YNC command has not been sent, it is checked whether a VSYNC request has been issued from the engine side (step ST21). And VSYN
If it is determined that no C request has been issued, the process returns to step STI and waits for a VSYNC request to be issued without executing the above series of steps again. Then, when it is determined in step ST2 1 that a VSYNC request has been issued, a VSYNC command is sent to the engine side (step ST22), and the process returns to step STI, where the horizontal synchronization signal HSYNCO and video clock VCLKO are input. transition to the waiting state.

In this state, in step ST20, VSY
When it is determined that the NC command has already been sent, it is checked whether the transfer of one page of image data has been completed (step ST26), and if the transfer of image data has not been completed, the scan buffer is The image data of the bit image stored in the horizontal synchronization signal HSYNCO
and is sent to the engine side in synchronization with the video clock VCLKO (step ST25). On the other hand, the CPU 401 returns to step STI and waits for the transfer of one page of image data to be completed while executing the series of steps described above again. When the transmission of the image data for one page is completed in this way, the process returns to step STI, and the printer control circuit 71 returns to the initial state, and the engine control circuit 71 returns to the state where the image data of the next page can be transferred. When the circuit finishes warming up (in the $ completion state)
Before exiting the initial processing routine and outputting a ready signal to the linter control circuit, the paper feed solenoid is turned on to prefeed the paper to the aligning switch. As a result, the processing time of the printer port control circuit is used to take out the alignment paper from the paper feed cassette and move it to the aligning switch, reducing the time required for each paper. As a result, the image failure time can be shortened. Further, even if the processing time of the printer control circuit follows the processing speed of the engine control circuit, the C paper feeding time during first printing can be shortened.

[Effects of the Invention] As described above, according to the present invention, when the preparation of the first control means for controlling the image forming means is completed, the image forming medium is moved in advance to the front of the image forming means, By waiting for image data from the second control means that generates image data for image formation by the image forming means, movement of the image forming medium is prevented even when the processing time in the second control means is long. Since the image processing is performed in advance, the time required for the movement can be shortened, and an image forming apparatus can be provided that can shorten the image processing time.

[Brief explanation of drawings]

The figures show an embodiment of the present invention; FIG. 1 is a configuration diagram showing the internal structure of a laser printer, FIG. 2 is an external perspective view of the laser printer, and FIG. 3 is a plan view showing the configuration of an operation panel. FIG. 4 is a block diagram showing the configuration of the main parts of the engine control section, FIG. 5 is a block diagram showing the structure of the engine control circuit, FIG. 6 is a block diagram showing the structure of the main parts of the printer control section, and FIG. The figure shows each signal that makes up the interface signal, FIG. 8 is a timing chart for explaining data path switching timing, FIG. 9 is a flowchart showing the operation of the engine control section, and FIG. 10 is a diagram showing the engine control section. 11 is a timing chart showing the operation of the printer control circuit. FIG. 11 is a flow chart showing the operation of the printer control circuit. I7... Photoreceptor, 21... Charging device, 12... Laser exposure unit, I9... Developing device, 20... Fixing device, 48... Aligning switch, 70-mount engine control circuit, 71... printer control circuit, 353...
...E2PROM, 401...CPU, 4f)2...
- R OM, 405...Video RAMSP...Paper (image forming medium).

Claims (1)

[Scope of Claims] An image forming means for forming an image on a medium to be imaged; a storage means in which the medium to be imaged is stored; a conveying means for feeding paper to the image forming means; a warming-up means for warming up the image forming means; and when the warming-up means finishes warming up the image forming means, the conveying means removes the image forming medium from the storage means; An image forming apparatus comprising: processing means for moving an image forming medium to a position near the image forming means by taking it out and transporting it.