JPH09269715A - Method and device for image forming and storage medium storing program readable by computer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the rear end of an image formed by thermal fixing on a recording medium from chipping off though the feeding state of the recording medium is varied such as at the time of continuous feeding by judging the continuous feeding state of the recording medium and controlling an image forming start timing. SOLUTION: Recording agent developed and transferred on recording paper S by an image forming part 9 is fixed by a thermal fixing device 10. When a printer controller 26 detects that the top end of the recording paper S passes a pair of paper feeding carrying rollers 6 and reaches a paper feeding sensor 7, a vertical synchronizing signal is sent out to a video controller 28 after the specified time of (t) seconds. The video controller 28 starts outputting picture signals for one page portion by synchronizing with its signal. The printer controller 26 counts the number of continous prints, and shortens the time (t) in accordance with the increase of the number of the continous prints. Thus, recorded images are shifted on the front side of the recording paper S in accordance with the increase of the number of the continous prints.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus for fixing a recording material developed and transferred on a predetermined recording medium fed by a thermal fixing device, an image forming method of the image forming apparatus, and a computer reading the same. The present invention relates to a storage medium storing a possible program.

[0002]

2. Description of the Related Art Conventionally, laser beam printers and copying machines have been known as image forming apparatuses of this type. In an image forming apparatus utilizing such an electrophotographic process, a heat roller fixing device is generally used as a fixing device for fixing a toner on a recording sheet, in which heat is applied from a fixing roller and pressure is applied to fuse the toner. ing.

In a heat roller fixing device, a halogen heater is installed inside a cylindrical roller and the fixing roller for heating to a predetermined temperature is formed of a material having heat resistance and predetermined elasticity such as silicon rubber. The pressure roller is arranged in pressure contact with each other to form a roller pair, and the recording paper on which the toner image is placed is passed between the roller pair to heat and pressurize and fix the toner on the recording paper. .

By the way, in recent years, from the viewpoint of quick start and power saving, an on-demand type fixing device is becoming mainstream instead of the above-mentioned heat roller fixing device. this is,
The heat capacity of the fixing device is reduced by using a heater such as ceramics and a thin film such as polyimide instead of the fixing roller. Since such an on-demand fixing device has a good temperature responsiveness, it is possible to turn off the power supply to the fixing device except during normal times.

Further, in such an on-demand fixing device, a drive source is usually provided on the pressure roller side to drive the thin film, and the conveying force of the recording paper is given by the pressure roller.

[0006]

However, in the conventional image forming apparatus, since the conveying speed of the recording paper is controlled by the diameter of the pressure roller, the pressure roller is cold at the beginning of recording and the diameters are compared. Compared to the transport speed when it is relatively small, the transport speed when the pressure roller expands and the diameter becomes large becomes faster than the transport speed when continuous recording, and if the recording operation is continued, the recorded image stretches, and in some cases There is a problem that the image at the rear end is lost.

FIG. 11 is a characteristic diagram showing an example of the relationship between the continuous recording number and the recording image extension rate by the conventional image forming apparatus. The horizontal axis indicates the continuous recording number and the vertical axis indicates the recording image extension rate. Shows. In this recording apparatus, the recorded image is extended by about 1% during continuous recording of 30 sheets as compared with the initial image, and is saturated thereafter. That is, 30 for the first recorded image.
The recording image of the first sheet extends about 3 mm as shown in FIG. 11 in the case of A4 size.

FIG. 12 is a schematic view showing an example of a recorded image formed by a conventional image forming apparatus, showing a case where 30 sheets are continuously recorded on an A4 size recording sheet.

As shown in this figure, when an image of 2 mm is continuously recorded up to the rear end of an A4 size sheet by using the above-mentioned on-demand fixing device, an image of about 3 mm extends in the rear end direction on the 30th sheet. Image loss of 1 mm occurs.

The present invention has been made to solve the above problems, and an object of the first to eleventh inventions of the present invention is to provide a continuous feeding state of a recording medium to be fed. By determining and controlling the image formation start timing, the trailing edge of the image formed by heat fixing on the recording medium is lost even if the feeding state of the recording medium changes as in continuous feeding. An image forming apparatus capable of forming an image on a recording medium without any need, an image forming method of the image forming apparatus, and a storage medium storing a computer-readable program.

[0011]

According to a first aspect of the present invention, an image is formed by fixing a recording material, which is developed and transferred by an image forming means and transferred onto a predetermined recording medium to be fed, by a thermal fixing device. The apparatus is provided with a determination means for determining the continuous feeding state of the recording medium, and a control means for controlling the image formation start timing of the image forming means based on the determination result of the determination means.

A second aspect of the present invention is a first aspect of generating predetermined image information from print information input from an external device.
Processing means, detecting means for detecting the leading edge of the fed recording medium, and the first means based on the detection result of the detecting means.
After the output request for the image information is sent to the processing means, the recording developed and transferred by the image forming means on the recording medium fed based on the image information output from the first processing means. It has a second processing means for controlling the image processing of the image forming means for fixing the agent by the heat fixing device, and a judging means for judging the continuous feeding state of the recording medium to be fed, and the judgment by the judging means. Based on the result, the second processing means variably controls the output timing of the output request.

A third aspect of the present invention is to generate predetermined image information from print information input from an external device.
Processing means, detecting means for detecting the leading edge of the fed recording medium, and the first means based on the detection result of the detecting means.
After the output request for the image information is sent to the processing means, the recording developed and transferred by the image forming means on the recording medium fed based on the image information output from the first processing means. It has a second processing means for controlling the image processing of the image forming means for fixing the agent by the heat fixing device, and a judging means for judging the continuous feeding state of the recording medium to be fed, and the judgment by the judging means. Based on the result, the first processing means variably controls the transmission timing of the image information.

In a fourth aspect of the present invention, the determining means determines the continuous feeding state by detecting the number of continuously fed recording media or the continuous feeding time of the recording medium.

According to a fifth aspect of the present invention, in the thermal fixing device, a heating body, a moving body that contains the heating body and moves at a constant speed with a recording medium, and a roller provided in contact with the moving body. And a recording material transferred to the recording medium fed by the moving body and the pressure member, and fixed under heat and pressure.

A sixth invention according to the present invention is a first invention for generating predetermined image information from print information inputted from an external device.
And the second processing means for controlling the image forming means based on the image information generated by the first processing means communicate with each other to thermally fix the image transferred to the recording medium. In an image forming method of an image forming apparatus for fixing with a container, a determination step of determining a continuous feeding state of a fed recording medium, and detecting a leading edge of the fed recording medium based on the determination result A first adjusting step for variably adjusting the timing of the output request of the image information to be sent from the second processing means to the first processing means.

A seventh invention according to the present invention is the first invention for generating predetermined image information from print information inputted from an external device.
And the second processing means for controlling the image forming means based on the image information generated by the first processing means communicate with each other to thermally fix the image transferred to the recording medium. In an image forming method of an image forming apparatus for fixing with a container, a determination step of determining a continuous feeding state of a fed recording medium, and detecting a leading edge of the fed recording medium based on the determination result A request step for sending an output request of the image information to the first processing means, and a start of sending the image information to be sent from the first processing means to the second processing means based on the request. And a second adjusting step for variably adjusting the timing.

According to an eighth aspect of the present invention, in the thermal fixing device, a heating body, a moving body that contains the heating body and moves at a constant speed with a recording medium, and a roller provided in contact with the moving body. An upper pressure member is provided, and the recording agent transferred to the recording medium fed by the moving body and the pressure member is fixed under heat and pressure.

According to a ninth aspect of the present invention, a determination step of determining the continuous feeding state of a fed recording medium, and detecting the leading edge of the fed recording medium based on the determination result. A computer-readable program including a first adjusting step of variably adjusting a timing of an output request of the image information to be sent from the second processing means to the first processing means. Is.

A tenth aspect of the present invention is directed to a determination step of determining a continuous feeding state of a recording medium to be fed, and detecting a leading end of the recording medium fed based on the determination result. A request step for sending an output request of the image information to the first processing means, and a start of sending the image information to be sent from the first processing means to the second processing means based on the request. A computer-readable program including a second adjustment step for variably adjusting the timing is stored.

An eleventh aspect of the present invention is a computer-readable program including a step of thermally and pressure-fixing a recording material transferred onto a recording medium fed by a moving body and a pressure member. Is stored.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION

[First Embodiment] FIG. 1 is a cross-sectional view illustrating the configuration of an image forming apparatus according to a first embodiment of the present invention, for example, a laser beam printer.

Reference numeral 1 is a laser beam printer main body (hereinafter referred to as main body). A cassette 2 stores a recording sheet S (cut sheet). 3 is a cassette paper presence sensor, which detects the presence or absence of the recording paper S in the cassette 2, and 4 is a cassette size sensor, which is composed of a plurality of microswitches and detects the size of the recording paper S in the cassette 2. A sheet feeding roller 5 feeds the recording sheet S from the cassette 2 into the main body 1.

Reference numeral 6 denotes a pair of paper feed / conveyance rollers for conveying the recording paper S fed by the paper feed roller 5, and 7 denotes a paper feed sensor.
The conveyance state of the recording paper S conveyed by the pair of paper feed conveyance rollers 6 is detected. A laser scanner unit 8 exposes a photosensitive drum 18, which will be described later, with laser. An image forming unit 9 forms a toner image on the recording paper S based on the laser light from the laser scanner unit 8.

Reference numeral 10 denotes a heat fixing device, which fixes the toner image formed on the recording paper S by the image forming section 9 under heat and pressure. 11
Is a paper ejection sensor for detecting the paper conveyance state of the paper ejection unit of the recording paper S on which the image is fixed by the thermal fixing device 10. A paper discharge roller 12 discharges the recording paper S. 13 is a storage tray,
The recording paper S discharged by the paper discharge roller 12 is accumulated.

The laser scanner section 8 is composed of a laser unit 14, a polygon motor 15, an image forming lens group 16, a folding mirror 17, etc.
4 emits laser light modulated based on an image signal (image signal VDO) sent from a video control device 28 described later, and the polygon motor 15 causes the laser unit 14 to operate.
Laser light from the imaging lens group 16, folding mirror 1
The photosensitive drum 18 to be described later is scanned via 7 or the like.

The image forming section 9 includes a photosensitive drum 18, a primary charging roller 19, a developing device 20, a transfer charging roller 21, and a cleaner 22, which are necessary for a known electrophotographic process.
And so on. The heat fixing device 10 includes a ceramic heater 10a, a thermistor 10b, and a polyimide film 10.
c, stay 10d, pressure roller 10e,
The ceramic heater 10a is a heating source, and the thermistor 10b
Detects the temperature of the ceramic heater 10a, the polyimide film 10c encloses the ceramic heater 10a and the thermistor 10b, and rotates with the conveyance of the recording paper.
The stay 10d holds the ceramic heater 10a, the thermistor 10b, and the polyimide film 10c, and the pressure roller 10e makes pressure contact with the ceramic heater 10a via the polyimide film 10c. That is, it has a heating body, a moving body that encloses the heating body and moves at the same speed as the recording sheet S, and a roller-shaped pressing member provided in contact with the moving body. The recording sheet is conveyed to the formed nip to perform heat and pressure fixing.

Reference numeral 23 denotes a main motor, which is a driving force for each unit of the image forming unit 9 including the paper feed roller clutch 24, the paper feed and conveyance roller pair 6, the photosensitive drum 18, the heat fixing device 10, the paper discharge roller 12 and the like. Is giving. The paper feed roller clutch 24 receives the driving force from the main motor 23 from the paper feed roller 5.
Give to.

A printer controller 26 controls the main body 1 and includes an MPU (microcomputer, ROM, which is provided with a timer, a ROM (stores a program shown in a flowchart of FIG. 8 described later), a RAM, and the like.
8 executes the program determination and processing shown in the flow chart of FIG. 8 stored in the control unit 1 to control the main body 1) and various input / output control circuits (not shown). The video control device 28 executes judgment and processing of the MPU (a program stored in the ROM and shown in the flowchart of FIG. 9 stored in the ROM, which is provided with a timer, a ROM (which stores the program shown in the flowchart of FIG. 9 described later), and a RAM. , Controlling the main body 1) and various input / output control circuits (not shown),
The printer controller 26 is connected via a video interface 27, which is an internal communication means. Further, the video control device 28 is connected to an external device 30 such as a personal computer via a general-purpose interface 29 such as a Centronics interface. Then, the video control device 28 receives the general-purpose interface 29 from the external device 30.
Image information transmitted via the
It is transmitted to the printer control device 26 via the video interface 27.

Each configuration and operation of the present embodiment and the first and fifth inventions of the present invention will be described below with reference to FIG.

In the first aspect of the invention, the recording agent developed and transferred by the image forming means (image forming section 9) on a predetermined recording medium (recording paper S) to be fed is fixed by the thermal fixing device 10. In the image forming apparatus, determination means for determining the continuous feeding state of the recording medium (recording paper S) (the MPU of the printer control device 26 or the MPU of the video control device 28 is determined based on the program stored in each ROM). Processing), the determination means (M of the printer control device 26)
The control unit (the MPU of the printer control unit 26 or the MPU of the video control unit 28) for controlling the image formation start timing of the image forming unit (image forming unit 9) based on the determination result of the PU or the MPU of the video control unit 28. Control processing is performed based on a program stored in each ROM), and the continuous feeding state of the recording paper S is controlled by the MPU of the printer controller 26 or the MPU of the video controller 28.
The MPU of the printer control device 26 or the MPU of the video control device 28 controls the image formation start timing of the image forming unit 9 based on the determination result of the MPU of the printer control device 26 or the MPU of the video control device 28. ,
Even if the feeding state of the recording medium fluctuates during continuous feeding, it is possible to prevent the trailing edge of the image formed by heat fixing on the fed recording medium.

In a fifth aspect of the invention, the thermal fixing device 10 includes a heating element (ceramic heater 10a) and the heating element (ceramic heater 10a) and moves so as to move at the same speed as a recording medium (recording paper S). Body (polyimide film 10c)
And a roller-shaped pressure member (pressure roller 10e) provided in contact with the moving body (polyimide film 10c), the moving body (polyimide film 10c) and the pressure member (pressure roller 10e). The recording material (toner) transferred onto the recording medium (recording paper S) fed by means of is fixed under heat and pressure, and is fed even when the roller-like pressure member thermally expands during continuous feeding. It is possible to prevent the trailing edge of the image formed by being thermally fixed on the recording medium.

FIG. 2 shows the printer control device 2 shown in FIG.
6 is a schematic diagram showing an example of a communication signal that the 6 and the video control device 28 communicate with each other via the video interface 27. FIG. The same components as those in FIG. 1 are denoted by the same reference numerals.

In the figure, CPRDY is a signal indicating that an external device can communicate, and is sent from the video control device 28 to the printer control device 26. PPRDY is a signal indicating that the printer controller 26 can communicate, and is sent from the printer controller 26 to the video controller 28. SBS
Y is a status valid signal which is sent from the printer controller 26 to the video controller 28. CBSY is a command valid signal, which is sent from the video controller 28 to the printer controller 26.

SC is a status / command signal. When the status valid signal SBSY is TRUE, it is sent from the printer controller 26 to the video controller 28 as status data indicating the internal state of the printer, and the command valid signal CBSY is TRUE. Video controller 2 in case
8 is sent from the video controller 28 to the printer controller 26 as command data indicating an instruction to the printer.

CLK is a synchronous clock of the status / command signal SC and is sent from the video controller 28 to the printer controller 26. Further, in response to one command from the video control device 28, the printer control device 26 returns one status corresponding to the command. That is, handshake type serial communication is performed using the status valid signal SBSY, the command valid signal CBSY, the status / command signal SC, and the synchronous clock CLK.

RDY is a ready signal, which is set to TRUE when the printer control device 26 is in a printable state and sent from the printer control device 26 to the video control device 28.
PRINT is a print signal that becomes TRUE when the external device 30 gives an instruction to start printing, and is sent from the video control device 28 to the printer control device 26. TOP
Is a vertical synchronizing signal for synchronizing the image output sent from the printer controller 26 to the video controller 28 in the vertical direction (sub-scanning direction / paper conveying direction).

HSYNC is a horizontal synchronizing signal for synchronizing the image output sent from the printer controller 26 to the video controller 28 in the horizontal direction (main scanning direction / laser scanning direction). VDO is an image signal at which the video control device 28 serially sends a dot image to the printer control device 26 in synchronization with the vertical synchronizing signal TOP and the horizontal synchronizing signal HSYNC.

FIG. 3 shows the printer control device 2 shown in FIG.
6 is a timing chart showing an operation of serial communication between the video control device 6 and the video control device 28.

In the figure, when the main body 1 is turned on, initialization of the printer controller 26 is completed, and serial communication is enabled, the printer controller 26 sets the signal PPRDY to TRUE. On the other hand, the video control device 28 is also turned on, and the initialization is completed,
When the serial communication becomes possible, the video controller 28
Sets the signal CPRDY to TRUE.

Then, the video controller 28 outputs the signal PPR.
After confirming that DY is TRUE for a predetermined time, it is determined that serial communication is possible, and if necessary, the command valid signal CBSY is set to TRUE and the synchronous clock CLK
An 8-bit command is transmitted from the status / command signal SC line in synchronism with. After that, the command valid signal CBSY is set to FALSE, and the printer controller 2
Wait for status return from 6.

On the other hand, when the printer control device 26 receives the command from the video control device 28, the status valid signal SBS is sent back to return the status corresponding to the content.
When Y is TRUE, the video controller 28 starts transmitting the synchronous clock CLK when detecting TRUE of the status valid signal SBSY, and the printer controller 26 synchronizes with the synchronous clock CLK and outputs the status from the status / command signal SC line. And the status valid signal SBSY is set to FALSE.

The printer control unit 26 sends the signal CP
When TRUE of RDY is confirmed for a predetermined time, it is determined that serial communication is possible, and the command is determined to be valid.

FIG. 4 is a timing chart showing a normal print sequence of the laser beam printer shown in FIG.

First, the printer control device 26 sets the ready signal RDY, which is in a print acceptance state, to TRUE to notify the video control device 28 that the print acceptance is possible. In response to this, the video control device 28, if a print request from the external device 30 is issued, sends a print signal PRINT.
T is set to TRUE to instruct to start printing. On the other hand, the printer control device 26 controls the TR of the print signal PRINT.
When the UE is detected, driving of the main motor 23 and the polygon motor 15 is started. When the main motor 23 is driven, the drive is transmitted to the pair of paper feeding / conveying rollers 6, the photosensitive drum 18, the thermal fixing device 10, the primary charging roller 19, the developing device 20, the transfer charging roller 21, and the paper discharging roller 12. At this time, high voltage driving of the primary charging roller 19, the developing device 20, and the transfer charging roller 21 is also performed.

Further, the heating of the ceramic heater 10a in the thermal fixing device 10 is started, and the energization duty of the ceramic heater 10a is controlled to adjust the temperature so that the temperature detected by the thermistor 10b becomes 170 ° C.

The printer controller 26 drives the paper feed roller 5 by turning on the paper feed roller clutch 24 for t2 seconds after t1 seconds when the rotation of the polygon motor 15 reaches a steady state.
The recording paper S is fed toward the feed / conveyance roller pair 6. Then, when the printer controller 26 detects that the leading edge of the recording sheet S has passed the pair of sheet feeding / conveying rollers 6 and has reached the sheet feeding sensor 7, the vertical synchronizing signal TOP outputs the vertical synchronization signal TOP after a predetermined time t3 seconds. Send to. The video control device 28 starts to output the image signal VDO for one page after tv seconds in synchronization with TOP.

During this time, the printer controller 26 sends the horizontal synchronizing signal HSYNC to the video controller 28 at a predetermined timing synchronized with the laser scanning, and modulates the laser light emitted from the laser unit 14 based on the image signal VDO. To do. By the above-mentioned operation, the recording sheet S
Is sequentially conveyed to the paper feed roller 5, the pair of paper feed and conveyance rollers 6, the image forming section 9, the thermal fixing device 10, and the paper ejection roller 12 for image recording. When the discharge sensor 11 detects the trailing edge of the recording paper S, the temperature control of the ceramic heater 10a is stopped, and the driving of each high pressure is stopped. Then, after t4 seconds, the main motor 23 and the polygon motor 15 are stopped, and the normal printing operation ends.

FIG. 5 shows the video controller 28 shown in FIG.
7 is a timing chart showing a signal transmission state between the printer control device 26 and the printer control device 26, which corresponds to the transmission state of the image signal VDO based on the horizontal synchronization signal HSYNC.

The printer controller 26 controls the horizontal synchronizing signal H.
When SYNC is sent to the video control device 28 at a predetermined timing synchronized with laser scanning, the video control device 28
Is synchronized with the rising edge of the horizontal synchronizing signal HSYNC,
After h, the image signal VDO for one scan is output.

By the way, when continuous printing is performed, the pressure roller 10e is heated by the heat generated from the ceramic heater 10a, causing thermal expansion and expansion of the outer shape. Therefore, the image extends as the number of continuous prints increases,
The MPU of the printer control device 26 counts the number of continuous prints, and the time t3 from the detection of the leading edge of the recording paper by the paper feed sensor 7 to the output of the vertical synchronization signal TOP signal to the video control device 28 is continuously performed. Shorten as the number of prints increases. As a result, the VDO signal output timing (t3 + tv) of the video control device 28 is shortened from the leading edge of the paper detected by the paper feed sensor 7, and the recorded image shifts to the front side of the recording paper S as the number of continuous prints increases. (The image forming timing on the recording paper becomes earlier).

Specifically, according to the number of continuous prints,
The time t3 is reduced stepwise (every 10 sheets) by a time corresponding to ½ of the image extension margin, and the thermal expansion of the pressure roller 10e is saturated and the image extension is saturated for 30 sheets or more. Holds its value.

The structure and operation of this embodiment and the second invention of the present invention will be described below with reference to FIGS.

A second aspect of the present invention is a first processing means (video control device 28) for generating predetermined image information (image signal VDO) from print information input from an external device (personal computer 30), and feeding. Detection means (paper feed sensor 7) for detecting the leading edge of the recording medium (recording paper S) to be recorded, and the first processing means (video control device 28) based on the detection result of the detection means (paper feed sensor 7). ) To the image information output request, and then the image information (image signal VDO) is output from the first processing means (video controller 28) via the video interface 27. The image processing of the image forming unit (image forming unit 9) for fixing the recording agent developed and transferred by the image forming unit (image forming unit 9) on the recording medium (recording paper S) by the thermal fixing device 10 is controlled. M of the second processing means and (printer control unit 26), determining means for continuously feeding state of the fed by the recording medium (recording paper S) (printer control unit that
PU performs judgment processing based on a program stored in an internal ROM), and the second processing means (printer control device 26) based on the judgment result of the judgment means (MPU of the printer control means). Variably controls the transmission timing (time t3) of the output request (vertical synchronization signal TOP) to the video control device 28, and the video control device 28 generates the image signal VDO from the print information input from the personal computer 30. The paper feed sensor 7 detects the leading end of the fed recording paper S, sends a vertical synchronization signal TOP to the video control device 28 based on the detection result of the paper feed sensor 7, and then outputs from the video control device 28. Of the image forming section 9 for fixing the recording agent developed and transferred by the image forming section 9 on the recording sheet S fed based on the image signal by the thermal fixing device 10. The image processing is controlled by the printer control device 26, the MPU of the printer control device 26 determines the continuous feeding state of the recording paper S to be fed, and the printer control means 26 is based on the determination result of the MPU of the printer control device 26. Variably controls the transmission timing time t3 of the vertical synchronizing signal TOP to the video control device 28 so that even if the feeding state of the recording medium changes during continuous feeding, it is thermally fixed on the fed recording medium. It is possible to prevent the defect of the rear end of the formed image.

The image control processing of the image control apparatus of the present invention will be described below with reference to FIGS.

FIG. 6 is a characteristic diagram for explaining an image expansion state during continuous printing by the main body 1 shown in FIG. 1. The horizontal axis indicates the number of continuous prints by the main body 1, and the vertical axis indicates the pressure roller. The recording image extension margin V1 when performing continuous printing due to the thermal expansion of the outer diameter of 10e and the transmission time t3 of the vertical synchronization signal TOP are shortened in accordance with the increase in the number of continuous prints, so that the recording image is printed on the front side of the recording paper S The image shift distance V2 (value obtained by dividing the t3 shortening time by the transport speed of the recording medium and converting the distance) is shown.

The image shift distance is set such that the time t3 is reduced stepwise (every 10 sheets) by a time corresponding to 1/2 of the image extension margin according to the number of continuous prints. Further, for the 30 sheets or more where the thermal expansion of the pressure roller 10e is saturated and the image extension is saturated, the value time t3 is set to the printer controller 26.
It is held in the RAM in the MPU.

FIG. 7 is a schematic diagram of output during continuous printing by the image forming apparatus shown in FIG.
It corresponds to the output results of the 20th, 30th, and 30th sheets.

As shown in the figure, since the image is shifted forward in accordance with the number of continuous prints, the image loss at the trailing edge does not occur.

FIG. 8 is a flow chart for explaining the first embodiment of the image forming method of the image forming apparatus of the present invention.
This corresponds to the processing of the printer control device 26. Note that (1)
(11) shows each step.

First, this control is performed by the printer controller 26.
Is started by receiving a print request command, and in step (1), the current continuous print number N stored in the RAM in the MPU of the printer controller 26 is initialized to 1. Next, in step (2), the feeding of the recording paper S by the paper feed roller 5 is started. Next, in step (3), the MPU of the printer control device 26 determines whether or not the current continuous print number N is 30th or less, and if it is determined that it is not 30th or less, the process proceeds to step (6). move on.

On the other hand, when it is determined in step (3) that the current continuous print number N is 30th or less, the MPU of the printer controller 26 determines that the current continuous print number N is 10 in step (4). It is judged whether it is a multiple of 1
If it is determined that it is not a multiple of 0, the process proceeds to step (6).

On the other hand, when it is determined in step (4) that the current number N of continuous prints is a multiple of 10,
In step (5), the vertical synchronization signal T to the video controller 28 is detected after the paper feed sensor 7 detects the leading edge of the recording paper.
The time t3 until the OP signal is output (the initial value of the time t3 is stored in the ROM or the like in the MPU of the printer control unit 26) is shortened by a time corresponding to 1/2 of the extension length of the image. Proceed to (6).

Next, in step (6), the printer waits until the paper feed sensor 7 detects the arrival of the recording paper S to be fed, and after it is determined that it has been detected, in step (7) the printer controller The timer in the 26 MPU is started. In step (8), the MPU of the printer controller 26 waits until the timer set in step (7) has elapsed time t3, and after it is determined that time t3 has elapsed, in step (9) the printer controller 2
The MPU 6 sends the vertical synchronization signal TOP to the video controller 28.
Send to

Next, in step (10), the printer control unit 26 determines whether printing of all pages has been completed.
If it is determined that the printing has not been completed, the current MPU N increments the current continuous printing sheet number N and returns to the process of step (2).

On the other hand, if it is determined in step (10) that printing of all pages has been completed, the process is completed.

As described above, even when the pressure roller 10e thermally expands due to the continuous printing operation to increase the conveying speed of the recording medium, the paper feed sensor 7 detects the leading edge of the paper and then the vertical synchronization to the video control device 28 is performed. By gradually reducing the time t3 until the signal TOP is transmitted, the video control device 28 detects the image signal VD after the paper feed sensor 7 detects the leading edge of the paper.
By shortening the time (t3 + tv) until the output of O, the image to be formed on the recording medium is shifted stepwise in the front end direction,
It is possible to prevent the trailing edge image from being lost due to the extension of the recorded image.

If the MPU of the printer controller 26 determines that the image size input from the external device 30 has a sufficient margin with respect to the trailing edge of the paper, the above control is not performed,
It is also possible that the image is not unnecessarily shifted toward the front end of the recording apparatus.

Correspondence between the present embodiment, the sixth invention and each step, its action and the ninth invention will be described with reference to FIG. 8 and FIG. 10 described later.

A sixth aspect of the present invention is directed to a first processing means (video control device 28) for generating predetermined image information (image signal VDO) from print information input from an external device (personal computer 30); Image information (image signal VD) generated by the first processing means (video control device 28).
A recording medium (recording paper S) that is fed by communicating with a second processing unit (printer control device 26) that controls the image forming unit (image forming unit 9) based on O) via the video interface 27. In the image forming method of the image forming apparatus in which the image transferred onto the image is fixed by the thermal fixing device 10, a determination step of determining the continuous feeding state of the recording sheet S to be fed (steps (3) and (4 in FIG. 8)). )) And the timing of the output request of the image information to be sent from the second processing means to the first processing means by detecting the leading end of the recording medium fed based on the determination result. To variably adjust the
Even if the feeding state of the recording medium fluctuates during continuous feeding by executing the adjustment step (steps (5) to (9) in FIG. 8)
(EN) It is possible to automate the process of preventing the rear end of an image formed by being thermally fixed on a fed recording medium.

A ninth aspect of the invention is a determination step (step (3) in FIG. 8, which is for determining the continuous feeding state of the recording paper S to be fed.
(4)), and based on the determination result, the leading edge of the recording medium is detected to detect the first
A computer-readable program including a first adjusting step (steps (5) to (9) in FIG. 8) for variably adjusting the timing of the output request of the image information to be sent to the processing means. Is used as a storage medium. That is, a mode in which the program code corresponding to the process shown in FIG. 8 is stored in a storage medium or an internal storage resource described later, and the MPU of the printer control device 26 reads out from the storage medium storing the program code and executes the present invention is also the present invention. Is included in the embodiment.

[Second Embodiment] In the first embodiment, recording is performed in which the sending timing of the vertical synchronizing signal TOP to the video control device 28, that is, the sending time t3 is counted after the paper feed sensor 7 detects the leading edge of the paper. By gradually shortening based on the value of the number of continuously fed media, the video control device 28 after the paper feed sensor 7 detects the leading edge of the paper.
Until the image signal VDO is output by (t3 + tv)
The video control device 2 has been described above.
8 receives the image signal VD after receiving the vertical synchronization signal TOP.
The time (t3 + tv) from when the paper feed sensor 7 detects the leading edge of the paper to when the video control device 28 outputs the image signal VDO may be shortened by shortening the time tv until O is output. . Hereinafter, the embodiment will be described.

Hereinafter, each configuration and operation of the present embodiment and the third invention will be described with reference to FIGS.

A third aspect of the present invention includes first processing means (video control device 28) for generating predetermined image information (image signal VDO) from print information input from an external device (personal computer 30), and feeding. Detection means (paper feed sensor 7) for detecting the leading edge of the recording medium (recording paper S) to be recorded, and the first processing means (video control device 28) based on the detection result of the detection means (paper feed sensor 7). ) Request for output of the image information (image signal VDO) (vertical synchronization signal TOP)
Is transmitted, the first processing means (video control device 2
8) Heat the recording agent transferred and developed by the image forming means (image forming section 9) on the recording medium (recording paper S) fed based on the image information (image signal VDO) outputted from 8). Second processing means (printer control device 26) for controlling the image processing of the image forming means (image forming portion 9) to be fixed by the fixing device 10, and continuous feeding state of the recording medium (recording paper S) to be fed. Based on the determination result of the determination means (the MPU of the video control device 28), and the determination means (the MPU of the video control device 28 performs determination processing based on a program stored in an internal ROM). The first processing means (video control device 28) variably controls the transmission timing (time tv) of the image information (image signal VDO), and the image is obtained from the print information input from the personal computer 30. No. VDO is generated by the video control device 28, the paper feed sensor 7 detects the leading edge of the recording paper S to be fed, and the video control device 28 is requested to output the image signal VDO based on the detection result of the paper feed sensor 7. (Vertical sync signal TO
P), the recording material (toner) developed and transferred by the image forming unit 9 on the recording paper S fed based on the image signal VDO output from the video control device 28.
The printer controller 26 controls the image processing of the image forming unit 9 for fixing the sheet by the thermal fixing device 10, and the MPU of the video controller 28 determines the continuous feeding state of the recording paper S to be fed. The video control device 28 variably controls the transmission timing of the image signal VDO based on the determination result of the MPU 28, so that even if the feeding state of the recording medium fluctuates during continuous feeding, the video signal is recorded on the fed recording medium. It is possible to prevent the rear end of the image formed by heat fixing from being damaged.

The image control processing of the image control apparatus of the present invention will be described below with reference to FIG.

FIG. 9 is a flow chart for explaining the second embodiment of the image forming method of the image forming apparatus of the present invention.
This corresponds to the processing of the video control device 28. In addition, (1)-
(10) shows each step.

First, this control is started when the video control device 28 receives a print request command from the personal computer 30, and in step (1), the current control is stored in the RAM in the MPU of the printer control device 28. The number N of continuously printed sheets is initialized to 1. Next, in step (2), the MPU of the printer control device 28 determines whether or not the current continuous printing number N is 30th or less, and 3
If it is judged that it is not the 0th or less, step (5)
Proceed to.

On the other hand, if it is determined in step (2) that the current continuous print number N is 30th or less, the MPU of the printer controller 28 determines that the current continuous print number N is 10 in step (3). It is judged whether it is a multiple of 1
If it is determined that it is not a multiple of 0, the process proceeds to step (5).

On the other hand, in step (3), when it is determined that the current continuous print number N is a multiple of 10,
In step (4), the time tv from when the video control device 28 receives the vertical synchronizing signal TOP from the printer control device 26 to when the video signal VDO is sent to the printer control device 26 (the initial value of the time tv is (Stored in the ROM or the like in the MPU of the video control device 28) is shortened by a time corresponding to ½ of the extension length of the image, and the process proceeds to step (5).

Next, in step (5), the video controller 28 waits until the vertical synchronizing signal TOP from the printer controller 26 is received, and after it is judged that the vertical synchronizing signal TOP is received, in step (6), the video control is performed. M of device 28
Start the timer in PU. In step (7), the MPU of the video control device 28 waits until the timer tv set in step (6) has elapsed, and after it is determined that the time tv has elapsed, in step (8), the video control device 28. The MPU sends the image signal VDO to the printer controller 26.

Next, in step (9), it is determined whether or not printing of all pages is completed by the M of the video controller 28.
If the PU determines that printing has not ended, in step (10), the current continuous print number N
Is incremented and the process returns to step (2).

On the other hand, if it is determined in step (9) that printing of all pages has been completed, the process is completed.

As described above, even when the pressure roller 10e thermally expands due to the continuous printing operation and the conveyance speed of the recording medium increases, the time tv from the reception of the vertical synchronization signal TOP to the output of the image signal VDO is By shortening, the time (t3 +) from when the paper feed sensor 7 detects the leading edge of the paper to when the video control device 28 outputs the image signal VDO.
By shortening tv), the image to be formed on the recording medium can be shifted to the leading end to prevent the trailing end image from being lost due to the extension of the recorded image.

If the MPU of the video control device 28 determines that the image size input from the external device 30 has a sufficient margin with respect to the trailing edge of the paper, the above control is not performed and the image is unnecessarily supplied. It is also possible not to shift toward the front end of the recording device to be sent.

The structure of the data processing program readable by the image processing apparatus according to the present invention will be described below with reference to the memory map shown in FIG.

FIG. 10 is a diagram for explaining a memory map of a storage medium that stores various data processing programs that can be read by the image processing apparatus according to the present invention.

Although not particularly shown, information for managing the program group stored in the storage medium, such as version information, creator, etc. is also stored, and information depending on the OS or the like on the program reading side, such as the program, is stored. In some cases, an icon or the like for identification display may be stored.

Furthermore, data dependent on various programs is also managed in the above directory. In addition, a program for installing various programs on a computer or a program for decompressing a program to be installed when the program to be installed is compressed may be stored.

The functions shown in FIG. 10 in this embodiment may be performed by this system by a program installed from the outside. And in that case, the CD
The present invention is also applied to the case where an information group including a program is supplied to the image processing apparatus according to the present invention from a storage medium such as a ROM, a flash memory, or an FD, or from an external storage medium via a network. Is.

Correspondence between the present embodiment and each step of the seventh invention and its action and the tenth invention will be described with reference to FIGS.
Description will be made with reference to 0 and the like.

In a seventh aspect of the present invention, there is provided a first processing means (video control device 28) for generating predetermined image information (image signal VDO) from print information input from an external device (personal computer 30), and the first processing means. Image information (image signal VD) generated by the first processing means (video control device 28).
The image transferred onto the recording medium (recording paper S) fed by communicating with the second processing means (printer control device 26) which controls the image forming means (image forming section 9) based on O). In the image forming method of the image forming apparatus for fixing by the thermal fixing device 10, a determination step (step (2) of FIG. 9,
(3)), and based on the determination result, the leading end of the recording medium (recording paper S) fed is detected to output the image information output request (vertical synchronization signal TOP). The request process (step (5) in FIG. 9) to be sent to the video control device 28) and the second processing from the first processing means (video control device 28) based on the request (vertical synchronization signal TOP). A second adjusting step (steps (4) to (7) in FIG. 9) for variably adjusting the sending start timing (time tv) of the image information (image signal VDO) to be sent to the means (printer controller 26). ) And, even if the feeding state of the recording medium fluctuates during continuous feeding, it is possible to automate the process of preventing the loss of the trailing edge of the image formed by heat fixing on the fed recording medium. .

A tenth aspect of the present invention is a determination step (steps (2) and (3) in FIG. 9) for determining the continuous feeding state of the recording medium (recording paper S) to be fed, and based on the determination result. The front end of the recording medium (recording paper S) that is fed by the first request to output the image information (vertical synchronization signal TOP).
Requesting step (step (5) in FIG. 9) to be sent to the processing means (video control device 28) and the request (vertical synchronization signal T).
OP) from the first processing means (video controller 28) to the second processing means (printer controller 2).
6) The image information (image signal VD
And a second adjusting step (steps (4) to (7) in FIG. 9) for variably adjusting the transmission start timing (time tv) of (O). The storage medium stores a computer-readable program. It is a thing. That is, a mode in which a program code corresponding to the process shown in FIG. 9 is stored in a storage medium or an internal storage power source described later, and the MPU of the video control device 28 reads out from the storage medium storing the program code and executes the present invention is also the present invention. Is included in the embodiment.

Correspondence between the present embodiment and each step of the eighth invention and its action and the eleventh invention will be described with reference to FIGS. 8, 9 and 10.

In an eighth aspect of the invention, the thermal fixing device 10 moves so as to include a heating body (ceramic heater 10a) and the heating body (ceramic heater 10a) and move at a constant speed with a recording medium (recording paper S). Body (polyimide film 10c)
And an on-roller pressure member (pressure roller 10e) provided in contact with the moving body (polyimide film 10c), the moving body (polyimide film 10c) and the pressure member (pressure roller 10e). The recording agent transferred to the recording medium (recording paper S) fed by the above is fixed by heat and pressure (not shown in the figure which is executed between step (9) and step (10) in FIG. 8). Process, step (7) in FIG.
(Not shown in the figure), a thermal pressure fixing step (not shown) is performed, and even when the roller-shaped pressure member thermally expands during continuous feeding, thermal fixing is performed on the fed recording medium. It is possible to automate the processing for preventing the loss of the trailing edge of the formed image.

The eleventh aspect of the invention is to heat and pressure fix a recording agent transferred onto a recording medium (recording paper S) fed by a moving body (polyimide film 10c) and a pressure member (pressure roller 10e). (Step (9) and step (10) in FIG. 8 (not shown), which is a heat and pressure fixing step, step (7) and step (8) in FIG. And a heat and pressure fixing step), which is a storage medium storing a computer-readable program. That is, a program code corresponding to the steps shown in FIGS. 8 and 9 is stored in a storage medium or an internal storage resource described later, and the MPU of the video control device 28 or the printer control device 26 is stored from the storage medium storing the program code. A form that the MPU reads and executes is also included in the embodiment of the present invention.

[Third Embodiment] In the first and second embodiments, the recording image is recorded at the leading end of the recording medium in accordance with the count value of the continuous print number of the recording paper S fed from the cassette 2. Although the case has been described where the control is performed so as to shift in the stepwise direction, the continuous print time is set to the printer control unit 26 instead of counting the number of continuous prints.
MPU counter or MP of video controller 28
It is also possible to perform the control of shifting the recorded image to the front end of the recording medium in accordance with the continuous printing time by counting with the U counter.

Correspondence between the present embodiment and each configuration of the fourth invention and its operation will be described below with reference to FIG.

A fourth aspect of the present invention is the determination means (MPU of the printer control device 26 or MP of the video control device 28).
U) detects the continuous feeding number or continuous feeding time of the recording medium (recording paper S) to determine the continuous feeding state, and even if the feeding state of the recording medium changes during continuous feeding. It is possible to more reliably prevent the trailing edge of the image formed by heat fixing on the fed recording medium.

As described above, the recording medium recording the program code of the software that realizes the functions of the above-described embodiments is supplied to the system or apparatus, and the computer (or CPU or MP of the system or apparatus is supplied.
It goes without saying that the object of the present invention is also achieved when U) reads out and executes the program code stored in the storage medium.

In this case, the program code itself read from the storage medium realizes the novel function of the present invention, and the storage medium storing the program code constitutes the present invention.

As a storage medium for supplying the program code, for example, a floppy disk, hard disk, optical disk, magneto-optical disk, CD-ROM, C
DR, magnetic tape, nonvolatile memory card, RO
M, EEPROM and the like can be used.

Further, by executing the program code read by the computer, not only the functions of the above-described embodiment are realized, but also the OS (operating system) running on the computer based on the instruction of the program code. It goes without saying that this also includes the case where the above) performs a part or all of the actual processing, and the processing realizes the functions of the above-described embodiments.

Further, after the program code read from the storage medium is written in the memory provided in the function expansion board inserted into the computer or the function expansion unit connected to the computer, based on the instruction of the program code, The CPU or the like provided in the function expansion board or function expansion unit performs a part or all of the actual processing,
It goes without saying that a case where the function of the above-described embodiment is realized by the processing is also included.

The present invention may be applied to a system composed of a plurality of devices or an apparatus composed of a single device. Needless to say, the present invention can be applied to a case where the present invention is achieved by supplying a program to a system or an apparatus. In this case, by reading a storage medium storing a program represented by software for achieving the present invention into the system or apparatus, the system or apparatus can enjoy the effects of the present invention. .

Further, by downloading and reading a program represented by software for achieving the present invention from a database on a network by a communication program, the system or apparatus can be
It is possible to enjoy the effects of the present invention.

[0106]

As described above, the first embodiment according to the present invention is described.
According to the eleventh aspect, even if the feeding state of the recording medium changes during continuous feeding, it is possible to prevent the trailing edge of the image formed by heat fixing on the fed recording medium from being damaged. It has the effect of being able to.

[Brief description of drawings]

FIG. 1 is a cross-sectional view illustrating a configuration of an image forming apparatus according to a first exemplary embodiment of the present invention.

FIG. 2 is a schematic diagram showing an example of communication signals with which the printer control device and the video control device shown in FIG. 1 communicate via a video interface.

3 is a timing chart showing an operation of serial communication between the printer control device and the video control device shown in FIG.

FIG. 4 is a timing chart showing a normal print sequence of the laser beam printer shown in FIG.

FIG. 5 is a timing chart showing a signal transmission state between the video control device and the printer control device shown in FIG.

6 is a characteristic diagram illustrating an image expansion state during continuous printing by the main body illustrated in FIG.

7 is a schematic diagram of output during continuous printing by the image forming apparatus shown in FIG.

FIG. 8 is a flowchart illustrating a first embodiment of an image forming method of an image forming apparatus of the present invention.

FIG. 9 is a flowchart illustrating a second embodiment of the image forming method of the image forming apparatus of the present invention.

FIG. 10 is a diagram illustrating a memory map of a storage medium that stores various data processing programs that can be read by the image processing apparatus according to the present invention.

FIG. 11 is a characteristic diagram showing an example of a relationship between the number of continuously recorded sheets and a recording image extension rate by the conventional image forming apparatus.

FIG. 12 is a schematic diagram showing an example of a recorded image formed by a conventional image forming apparatus.

[Explanation of reference numerals] 1 laser beam printer main body 8 laser scanner section 9 image forming section 10 thermal fixing device 10a ceramic heater 10b thermistor 10c polyimide film 10d stay 10e pressure roller 26 printer controller 28 video controller

Claims (11)

[Claims] 1. An image forming apparatus in which a thermal fixing device fixes a recording agent developed and transferred by an image forming unit on a predetermined recording medium to be fed, and determines the continuous feeding state of the recording medium. An image forming apparatus comprising: a determination unit and a control unit that controls an image formation start timing of the image forming unit based on a determination result of the determination unit. 2. A first processing means for generating predetermined image information from print information input from an external device, a detection means for detecting a leading edge of a recording medium to be fed, and a detection result of the detection means. Based on the image information output request to the first processing means, the image forming means develops the image on the recording medium fed based on the image information output from the first processing means. A second processing means for controlling the image processing of the image forming means for fixing the recording material transferred by the thermal fixing device by a thermal fixing device, and a judging means for judging the continuous feeding state of the fed recording medium, An image forming apparatus, wherein the second processing means variably controls a transmission timing of the output request based on a determination result of the determination means. 3. A first processing means for generating predetermined image information from print information input from an external device, a detection means for detecting the leading end of a recording medium to be fed, and a detection result of the detection means. Based on the image information output request to the first processing means, the image forming means develops on the recording medium fed based on the image information output from the first processing means. A second processing means for controlling the image processing of the image forming means for fixing the recording material transferred by the thermal fixing device by a thermal fixing device, and a judging means for judging the continuous feeding state of the fed recording medium, An image forming apparatus, wherein the first processing means variably controls a transmission timing of the image information based on a determination result of the determination means. 4. The determination means according to claim 1, wherein the determination means determines the continuous feeding state by detecting the continuous feeding number or continuous feeding time of the recording medium. Image forming apparatus. 5. The thermal fixing device includes a heating body, a moving body that encloses the heating body and moves at a constant speed with a recording medium, and a roller-shaped pressing member provided in contact with the moving body. The image forming apparatus according to any one of claims 1 to 3, wherein the recording material transferred onto the recording medium fed by the moving body and the pressure member is fixed by heat and pressure. 6. A first processing means for generating predetermined image information from print information input from an external device, and a first processing means for controlling the image forming means based on the image information generated by the first processing means. In the image forming method of the image forming apparatus in which the image transferred to the recording medium fed by communicating with the second processing means is fixed by the thermal fixing device, the continuous feeding state of the recording medium fed is determined. Determination step and timing of output request of the image information to be sent from the second processing means to the first processing means by detecting the leading end of the recording medium fed based on the determination result And a first adjusting step of variably adjusting the image forming method. 7. A first processing means for generating predetermined image information from print information input from an external device, and a first control means for controlling the image forming means based on the image information generated by the first processing means. In the image forming method of the image forming apparatus in which the image transferred to the recording medium fed by communicating with the second processing means is fixed by the thermal fixing device, the continuous feeding state of the recording medium fed is determined A determination step, a request step of detecting the leading end of the recording medium fed based on the determination result and sending an output request of the image information to the first processing means, and the request step based on the request. And a second adjusting step of variably adjusting a sending start timing of the image information to be sent from the first processing means to the second processing means. 8. The thermal fixing device includes a heating body, a moving body that encloses the heating body and moves at a constant speed with a recording medium, and a roller pressing member provided in contact with the moving body. 8. The image forming method for an image forming apparatus according to claim 6, wherein the recording material transferred to the recording medium fed by the moving body and the pressure member is fixed under heat and pressure. 9. A determination step of determining a continuous feeding state of a recording medium to be fed, and a leading edge of the recording medium fed based on a result of the determination to detect the leading edge of the recording medium from the second processing means. A storage medium storing a computer-readable program including a first adjusting step of variably adjusting a timing of an output request of the image information to be sent to a first processing means. 10. A determination step of determining a continuous feeding state of a fed recording medium, and detecting a leading edge of the fed recording medium based on the determination result to issue an output request of the image information. A request step of sending to the first processing means, and a second step of variably adjusting the sending start timing of the image information to be sent from the first processing means to the second processing means based on the request. A storage medium storing a computer-readable program including an adjusting step. 11. A computer-readable program including a step of thermally and pressure-fixing a recording material transferred onto a recording medium fed by a moving body and a pressure member is stored. Storage medium.