JP2021081669A - Image forming apparatus - Google Patents

Abstract

To prevent occurrence of unnecessary drive time of an image forming unit.SOLUTION: An image forming apparatus has: control means that, when an image forming request is received, controls a second preparation operation involving drive of photoreceptors for image forming means to execute image formation, and independent of the image forming request and before the second preparation operation, a first preparation operation involving the drive of the photoreceptors for preparation of the image forming means; measuring means that measures a temperature of fixing means; and calculation means that calculates time required for a preparation operation for the fixing means from paper size, a color mode, and paper type information obtained from the image forming request and a temperature condition obtained by the measuring means. When the image forming request is received, the control means causes to perform the preparation operation for the fixing means, and when the time required for the preparation operation for the fixing means calculated by the calculation means becomes longer than the time required for the second preparation operation determined according to details of image formation, the control means stops the first preparation operation and starts the first preparation operation after the preparation operation for the fixing means.SELECTED DRAWING: Figure 13

Description

The present invention relates to an image forming apparatus that detects a sheet size of a copier, a printer, or the like and feeds the sheet. The present invention relates to a method for controlling a preparatory operation when an image forming request is made during a preparatory operation of an image forming apparatus.

In the conventional image forming apparatus, a preparatory operation accompanied by driving an image forming unit is performed in order to put the image forming apparatus into a state capable of performing an image forming operation at the time of power activation, power saving restoration, jam restoration, door opening / closing, etc. There is. When the image formation request is received in the standby state in which the preparatory operation is completed, the image formation preparatory operation is started according to the requested image formation content.

Patent Document 1 compares the image formation preparation completion time of a unit other than the image forming unit and the image forming unit when the next image forming operation request occurs during the completion of the image forming operation and the stop processing. Therefore, when the image formation preparation operation of the unit other than the image forming unit takes longer than the image formation preparation operation of the image forming unit, the preparation continuation control is not executed, so that the image forming unit is useless. Controls have been proposed that suppress the occurrence of drive time and reduce the effect on life.

Japanese Unexamined Patent Publication No. 2016-133779

In Patent Document 1 described above, when an image formation request is made during the preparatory operation for putting the image forming apparatus into a state in which the image forming operation can be performed, the start-up preparatory operation to the image forming preparatory operation without stopping the image forming unit. In an image forming apparatus equipped with continuous control, the preparation time of the fuser when the fuser is in a cooled state, such as when the apparatus is started up, is compared with the image formation preparation completion time of the image forming unit. Then, when the preparation time of the fuser is long and takes a long time, the preparation continuation control is not executed.

However, as in Patent Document 1 above, the time required for image formation preparation of the image forming portion often takes longer when cooling is required than when heating by starting up the fuser. In addition, the target temperature of the fuser does not depend only on the temperature of the fuser itself, and the paper size, paper type, mode switching, etc. obtained from the paper information of the image formation request and the paper information at the time of the immediately preceding image formation, etc. There was a problem that it was difficult to make a correct decision to implement the preparation continuation control because it fluctuates greatly depending on the information and the time required for cooling also fluctuates.

In order to solve the above problems, the image forming apparatus according to the present invention is used.
An image forming means for forming a toner image on a photoconductor and transferring the formed toner image to paper to form an image.
A receiving means for receiving an image forming request for performing image forming by the image forming means, and
When the image forming request is received by the receiving means, the second preparatory operation accompanied by the driving of the photoconductor for the image forming means to execute the image formation and the second preparatory operation independent of the image forming request. Prior to, a control means for controlling the first preparatory operation involving the drive of the photoconductor for the preparation of the image forming means, and
A fixing means for fixing an image formed on paper by the image forming means, and a fixing means.
A measuring means for measuring the temperature of the fixing means and
A calculation means for calculating the time required for the preparation operation of the fixing means based on the paper size, color mode, and paper type information obtained from the image formation request and the temperature conditions obtained by the measuring means.
Have,
Upon receiving the image formation request, the control means causes the fixing means to perform a preparatory operation, and the time required for the preparatory operation of the fixing means calculated by the calculation means is determined according to the content of the image formation. If it becomes longer than the time required for the second preparatory operation, the first preparatory operation is stopped, and after the preparatory operation of the fixing means, the first preparatory operation is started.

According to the image forming apparatus according to the present invention, even if the preparation time of the fixing apparatus is extended due to the switching of the printing mode or the change of the paper size condition, the generation of unnecessary driving time of the image forming portion is suppressed and the life is extended. The influence of can be reduced.

The figure which shows the whole structure of the image forming apparatus The figure which shows the image formation part The figure which shows the operation part Configuration diagram of the fuser Block Diagram Explanatory drawing of image formation preparation operation Explanatory diagram of preparation continuous control Explanatory drawing at the time of preparatory operation continuation judgment Explanatory drawing at the time of preparatory operation stop judgment Table to set the target temperature from the paper information and the fuser status A table that calculates the cooling time from the target temperature and the fuser temperature Flow chart diagram of the embodiment of the present invention A flowchart describing the details of calculating the fuser preparation time according to the embodiment of the present invention.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

[First Embodiment]
<Structure of image forming apparatus>
FIG. 1 is a diagram showing the configuration of the entire image forming apparatus of the present invention.

The image forming apparatus 10 includes an image forming unit 200, a document reading unit 300, an operation unit 400, and a sheet storage unit 500.

<Image forming part>
FIG. 2 is a diagram showing the detailed configuration of the image forming unit 200 of the image forming apparatus 10, and shows four colors, that is, yellow (hereinafter referred to as Y), magenta (hereinafter referred to as M), and cyan (hereinafter referred to as C). It shows a color image forming apparatus provided with a black (hereinafter referred to as K) image forming means.

The photosensitive drums 100a to 100d are photosensitive drums on which electrostatic latent images for Y, M, C, and K are formed (a, b, c, and d indicate those for Y, M, C, and K, respectively). ..

The monochrome drum motor 109 drives the photosensitive drum 100d and the intermediate transfer roller 105. In the color drum motor 111, the color drum motor 111 drives the photosensitive drums 100a to 100c.

The developing motor 110 drives the developing machines 103a to 103d, and the driving of each developing device is turned on / off by a clutch provided in each developing device (not shown).

The laser scanners 101a to 101d perform exposure according to the image signal and form an electrostatic latent image on the photosensitive drum 100. The electrostatic latent image formed on each photosensitive drum 100 is toner-developed by the developer 103 to form a toner image.

The intermediate transfer belt 104 is rotated by the intermediate transfer roller 105 to sequentially transfer the toner image formed on each photosensitive drum 100.

The primary transfer rollers 102a to 102d transfer the toner image formed on the photosensitive drums 100a to 100d onto the intermediate transfer belt 104.

Reference numeral 112 denotes a separation motor provided for separating the primary transfer rollers 102a to 102c of the collar. When the monochrome image is output, the primary transfer rollers 102a to 102c are separated by the separation motor 112, so that the monochrome image forming operation can be performed with the color drum motor 111 stopped.

Reference numeral 106 denotes a secondary transfer roller that collectively transfers the toner image to the paper that has been conveyed to the electrostatic latent image formed on the intermediate transfer belt 104. Reference numeral 108 denotes a motor for driving the fixing roller.

<Operation unit>
The operation unit 400 of FIG. 3 is composed of a touch panel type operation screen 401 and button keys 402 such as number keys, print start and stop keys, and the user can perform various operations of the image forming apparatus 10.

<Original reader>
When the operation unit 400 receives a print instruction, the image forming apparatus 10 reads the document by the document reading unit 300, and the image signal of each color is sent to each laser scanner 101. Further, when a print instruction is received from the host computer 211 described later via the communication controller 210 described later, an image signal of each color is sent to each laser scanner 101.

Then, an electrostatic latent image is formed on the photosensitive drum 100, and the electrostatic latent image on the photosensitive drum 100 is developed with toner by the developer 103. The intermediate transfer belt 104 rotates clockwise, and the toner image formed on the photosensitive drum is sequentially transferred to the intermediate transfer belt 104 via the primary transfer roller 102.

After that, the paper is conveyed from the sheet storage unit 500 in the direction of the arrow, the toner image formed on the intermediate transfer belt is transferred at once at the position of the secondary transfer roller 106, and the toner is transferred to the paper by the heat of the fixing device 107. The image is fixed and discharged to the outside.

As shown in FIG. 4, the fuser 107 includes a thermistor 151 for detecting the temperature at the central portion and a sub thermistor 152 for detecting the temperature at the end portion.

<Block diagram>
Next, the configuration of the image forming apparatus 10 will be described with reference to the block diagram of FIG.

The image forming control unit 212 of the image forming apparatus 10 is controlled by the CPU circuit unit 213 composed of the CPU 201, ROM 202, and RAM 203.

An instruction to start image formation is received from the host computer 211 via the operation unit 400 or the communication controller 210. The received job is the CPU circuit unit 213, which exchanges data such as job information, and executes various programs stored in the ROM 202 based on the instruction from the CPU circuit unit 213.

Then, the monochrome drum motor 109, the color drum motor 111, the developing motor 110, the separation motor 112, and the laser scanner 101 of the image forming apparatus 10 are controlled, and the fixing motor 108 and the fixing device 107 are controlled to perform the image forming operation. ..

<Preparation operation>
Next, the preparatory operation for putting the image forming apparatus 10 into a state in which the image forming operation can be performed will be described.

Since the preparatory operation is a preparatory operation in the stage before the image formation request comes, in the color mode in which all the photosensitive drums 100 are driven so that the color image formation operation can be performed immediately in case a color image formation request comes. Perform a preparatory operation.

For example, in the preparatory operation when the power is turned on or when the power is restored, when the internal state of the image forming apparatus 10 has changed due to being left for a long period of time, an image for making the image density constant, which is a known technique, is used. Perform density correction control, color shift correction control, and the like.

In the recovery operation after the occurrence of jam, cleaning control, which is a known technique, is performed in order to remove the toner remaining on the intermediate transfer belt 104 and the photosensitive drum 100.

The description of the image density correction control, the color shift correction control, and the cleaning control is omitted because it is a known technique.

<Image formation preparation operation>
Next, a conventional general image formation preparation operation performed in response to an image formation request from the standby state in which the image forming unit 200 of the image forming apparatus 10 is stopped will be described.

FIG. 6 is a diagram showing the relationship between the image forming preparation operation of the fixing device 107 and the image forming unit 200 when the image forming request is received.

When the CPU 201 receives an image formation request, the fixing device 107 and the image forming unit 200 determine the content of the image forming preparation operation according to the information given to the request, for example, the color mode and the paper type.

In response to the image formation request, the fuser 107 starts temperature control control as an image formation preparatory operation, but the image forming unit 200 waits without starting the preparatory operation. When the fixing temperature of the fixing device 107 reaches the image formation preparation permission temperature, the image forming unit 200 starts the unit driving of the photosensitive drum 100, the developing device 103, and the high-pressure start-up operation. When the fixing temperature of the fuser 107 reaches the image formation permitted temperature and the image formation preparation operation of the image forming unit 200 is completed, the image forming operation becomes possible.

The above-mentioned image formation preparation permission temperature is determined based on the characteristics of the fixing start-up time from the relationship between the time when the fixing device 107 reaches the image formation permission temperature and the time when the image formation preparation operation of the image forming unit 200 is completed. doing. In this way, by controlling the start timing of the image formation preparation operation of the image forming unit 200, wasteful driving time is eliminated and the influence on the life is suppressed.

<Preparation continuation control>
Next, the preparation continuation control will be described.

FIG. 7 is a diagram illustrating the movement of the image forming unit 200 until the image forming unit 200 is in a state where the image can be formed when an image forming request for color image output is generated during the preparatory operation after the jam return.

The operation when the preparation continuation control is not performed will be described with reference to FIG. 7-a.

When the jam is restored, the image forming unit 200 starts driving the monochrome drum motor 109 and the color drum motor 111, and the preparatory operation is started.

When the speeds of the monochrome drum motor 109 and the color drum motor 111 rise to a constant speed, the separation motor 112 is driven to start the operation of bringing the primary transfer rollers 102a to 102c for color into contact with the photosensitive drums 100a to 100c (step S-). A1).

When the contact operation of the primary transfer rollers 102a to 102c is completed, the high voltage output required for the cleaning process is performed and the cleaning operation is started (step SA2).

An image formation request is generated during the cleaning process, but the issuance of the image formation request itself is suspended or accepted, but the image formation preparation operation is suspended (step SA3).

When the cleaning process is completed, the separation motor 112 is driven to stop the preparatory operation, and the operation of separating the primary transfer rollers 102a to 102c for color from the photosensitive drums 100a to 100c is started (step SA4).

When the separation operation is completed, the driving of the monochrome drum motor 109 and the color drum motor 111 is stopped, and when the motor stop is completed, the preparatory operation is completed (step SA5).

When the pre-preparation operation is completed, the image formation preparatory operation is started, and the monochrome drum motor 109 and the color drum motor 111 are started up again (step SA6).

Upon completion of the start-up operation of the monochrome drum motor 109 and the color drum motor 111, the separation motor 112 is driven to start the operation of contacting the primary transfer rollers 102a to 102c for color with the photosensitive drums 100a to 100a (). Step SA7).

When the contact operation of the primary transfer rollers 102a to 102c is completed, the high voltage output required for color image formation is performed (step SA8).

When the high-voltage output is completed, the image formation preparation operation is completed and the image formation OK state is obtained.

The time from when the image formation request is generated until the image formation preparation operation becomes possible is Tm-1.

Next, the operation when the preparation continuation control is performed will be described with reference to FIG. 7-b.

When the jam is restored, the image forming unit 200 starts driving the monochrome drum motor 109 and the color drum motor 111, and the preparatory operation is started.

When the speeds of the monochrome drum motor 109 and the color drum motor 111 rise to a constant speed, the separation motor 112 is driven to start the operation of bringing the primary transfer rollers 102a to 102c for color into contact with the photosensitive drums 100a to 100c (step S-). B1).

When the contact operation of the primary transfer rollers 102a to 102c is completed, the high voltage output required for the cleaning process is performed and the cleaning operation is started (step SB2).

It is memorized that the image formation request is notified during the cleaning operation (step SB3).

When the cleaning operation is completed, the preparatory operation ends, but the high voltage output is continuously performed as the image formation preparatory operation required for color image formation. When the high-voltage output is completed, the image formation preparation operation is completed and the image formation OK state is obtained.

The time from when the image formation request is generated until the image formation preparation operation becomes possible is Tm-2.

From the above description, in FIG. 7-b, even if the processes of steps SA4 to SA8 are not performed, the primary transfer rollers 102a to 102c and the color drum motor 111 are in a state where a color image can be formed, so that the process is continued. The image formation preparation operation can be performed. Therefore, the time from the generation of the image formation request to the end of the image formation preparation operation can be shorter for Tm-2 than for Tm-1. As a result, the time until the start of image formation can be shortened.

<Judgment control>
Next, the control for determining whether or not the preparation continuation control can be performed in the present invention will be described with reference to FIGS. 8 and 9.

FIG. 8 shows the relationship between the image formation preparation operation of the image forming unit 200 and the fixing device 107 and the preparing time of the fixing device when the cooling time of the fixing device is not required and the image forming preparation operation is not interrupted based on the fixing preparation determination. It is an image.

When the image forming unit is started up and the preparatory operation is started by starting the power supply, returning from the sleep state, closing the door cover, jam recovery processing, etc., the fixing device 107 is separated by the separating mechanism of the fixing roller. Do. The image forming unit 200 drives the monochrome drum motor 109 and the color drum motor 111 to drive the photosensitive drums 100 of all colors in order to execute the cleaning control and the image density control described above, and performs the necessary preparatory operations. To do. When the image forming request is notified during the preparatory operation of the image forming unit 200, the image forming unit 200 and the fixing device 107 send the paper size, the color mode, the paper type information, the temperature state of the fixing device, etc. given to the image forming request. To determine the content to be executed in the image formation preparation operation.

The CPU 201 calculates the time T1 from the reception of the image formation request of the image forming unit 200 to the completion of the above-mentioned image forming preparation operation. The time T1 is the time until the drive speeds of the monochrome drum motor 109 and the color drum motor 111 rise to a constant speed, and the operation of driving the separation motor 112 to bring the primary transfer rollers 102a to 102d into contact with the photosensitive drums 100a to 100d. Calculate by combining the time and cleaning operation time. Since the control required for preparation differs depending on the content of the image formation request, the time T1 also changes.

Similarly, the CPU 201 is based on the paper size, color mode, and paper type information given to the image formation request, and the current temperature of the fuser obtained from the main thermistor 151 and the sub thermistor 152 provided in the fuser 107. The target temperature is determined from the table shown in FIG. 10, and the fuser preparation time T2 of the fuser 107 is calculated from the target temperature of the fuser and the temperatures of the main thermistor and the end thermistor from the table shown in FIG. 11 as an example.

In the case of FIG. 8, since the time from when the image formation request is received until the image formation preparation operation is completed has a relationship of T1 ≧ T2, the image forming unit 200 waits for the completion of the image formation preparation operation of the fixing device 107. Is not in a state of idling, so the preparatory continuation control for continuing the image forming preparatory operation from the preparatory operation without stopping the driving of the image forming unit 200 is performed.

This case mainly includes a case where there is no change between the information on the paper on which the image was formed immediately before and the information on the image formation request.

In the case of FIG. 9, as an example, when there is a change in the direction in which the image formation required size increases from the paper size for which the image formation was performed immediately before, and the target temperature of the fuser is set low, the image formation occurs. Since the time from when the request is received until the image formation preparation operation is completed has a relationship of T1 <T2, the image forming unit 200 idles the image forming unit 200 in order to wait for the completion of the image forming preparation operation of the fuser 107. It will be in a state of doing. Therefore, in consideration of the life, the preparatory operation of the image forming unit 200 is stopped, and the image forming preparatory operation is restarted after the preparation of the fuser is completed.

This case mainly includes a case where there is a change in width size, mode, paper type, etc. between the information of the paper on which the image was formed immediately before and the information of the image formation request.

<Flowchart>
FIG. 12 is a flowchart of preparation continuation control in the present invention.

This flowchart is started when the CPU 201 determines that an image formation preparation operation such as power activation, recovery from the sleep state, closing of the door cover, and jam recovery processing is necessary.

The CPU 201 determines whether or not an image formation preparatory operation such as power activation, sleep recovery, door closing, and jam recovery processing is necessary, and if it determines that it is necessary, starts the preparatory operation of the image forming unit 200 (S1001).

When the CPU 201 receives an image formation request (S1002), the CPU 201 starts calculating the fuser preparation time T2 (S1003).

Next, the CPU 201 compares the fuser preparation time T2 and the image formation preparation time T1 (S1004).

When the image formation preparation time T1 is longer than the fuser preparation time T2, the pre-preparation operation is continued, and after the pre-preparation operation is completed, the image formation preparation operation is continuously started (S1007).

When the fuser preparation time T2 is longer than the image formation preparation time T1, the preparatory operation is stopped (S1005).

Confirmation is performed until the preparation of the fuser is completed by carrying out the cooling operation of the fuser (S1006).

Then, after the preparation of the fuser is completed, the image formation preparation operation is started again (S1007), and after the image formation preparation operation is completed (S1008), the image formation operation is started (S1009).

FIG. 13 is a flowchart illustrating the details of the subroutine for calculating the fuser preparation time in S1003 of FIG.

The CPU 201 compares the size in the width direction from the paper size information obtained from the image formation request and the size information of the paper on which the image was formed immediately before (S1101).

If the size in the width direction obtained from the image formation request is larger, then the temperatures of the main thermistor 151 and the sub thermistor 152 of the fuser 107 are checked (S1102).

If the temperature difference between the main thermistor 151 and the sub thermistor 152 is equal to or greater than the predetermined temperature (X1), then the temperature of the current fuser, the temperature difference between the main thermistor 151 and the sub thermistor 152, and the image formation request are met. The determined target temperature of the fuser (X2) is compared with the current temperature of the fuser (S1106), and if the current temperature of the fuser is higher than the target temperature of the fuser, the fuser is cooled. The time T2a is calculated (S1107), and the fuser preparation time T2 is calculated (S1108).

In step S1101, if the size in the width direction obtained from the image formation request is equal to or smaller than the paper on which the image was formed immediately before, then a switch from the color operation to the monochrome operation occurs. Check if it is (S1103).

As a result of the above confirmation, when switching from the color operation to the monochrome operation has occurred, the temperature of the fuser is then confirmed from the main thermistor 151 of the fuser 107.

Next, the current fuser temperature is compared with the target temperature (X2) of the fuser determined according to the image formation request (S1105), and the current fuser temperature is higher than the target temperature of the fuser. The cooling time T2a of the fuser is calculated (S1107), and the fuser preparation time T2 is calculated (S1108).

In step S1103, if the switching from the color operation to the monochrome operation has not occurred from the information of the image formation request and the job that formed the image immediately before, the paper type obtained from the image formation request is then obtained. From the information and the paper type information of the paper on which the image was formed immediately before, it is confirmed whether or not the paper type has been switched from plain paper to thin paper under the condition that the target temperature of the fuser drops (S1104). ).

As a result of the above confirmation, if the paper type is switched under the condition that the target temperature of the fuser is lowered, the temperature of the fuser is then confirmed by the main thermistor 151 of the fuser 107.

Similarly to the above, next, the current fuser temperature is compared with the target temperature (X2) of the fuser determined according to the image formation request (S1105), and the current fuser temperature is the target temperature of the fuser. If it is higher than, the fuser cooling time T2a is calculated (S1107), and the fuser preparation time T2 is calculated (S1108).

In step S1104, when the paper type is not switched under the condition that the fixing temperature of thick paper, plain paper, thin paper, etc. is lowered from the information of the image formation request and the job that formed the image immediately before, or step S1105. , S1106, when the current temperature of the fuser is less than the target temperature (X2) of the fuser determined in response to the image formation request, the fuser preparation time T according to the target temperature of the fuser is set. Calculate (S1108).

By these controls, detailed fixing is performed from the information such as the paper size, paper type, and mode switching obtained from the paper information of the image formation request and the paper information at the time of the immediately preceding image formation, and the current temperature state of the fuser. By calculating the cooling time of the device, it is possible to eliminate unnecessary driving time and suppress an adverse effect on the service life even when the cooling control of the fuser, which takes a long time, is involved.

10 image forming apparatus, 100 photosensitive drum, 101 laser scanner,
102 Primary transfer roller, 104 Intermediate transfer belt,
105 Intermediate Transfer Roller, 106 Secondary Transfer Roller, 107 Fixer,
108 fixing motor, 109 monochrome drum motor,
110 development motor, 111 color drum motor,
112 separation motor, 151 main thermistor,
152 sub-thermistor, 200 image forming unit, 201 CPU,
202 ROM, 203 RAM, 212 image formation control unit,
300 document reading unit, 400 operation unit, 500 sheet storage unit

Claims (1)

An image forming means for forming a toner image on a photoconductor and transferring the formed toner image to paper to form an image.
A receiving means for receiving an image forming request for performing image forming by the image forming means, and
When the image forming request is received by the receiving means, the second preparatory operation accompanied by the driving of the photoconductor for the image forming means to execute the image formation and the second preparatory operation independent of the image forming request. Prior to, a control means for controlling the first preparatory operation involving the drive of the photoconductor for the preparation of the image forming means, and
A fixing means for fixing an image formed on paper by the image forming means, and a fixing means.
A measuring means for measuring the temperature of the fixing means and
A calculation means for calculating the time required for the preparation operation of the fixing means based on the paper size, color mode, and paper type information obtained from the image formation request and the temperature conditions obtained by the measuring means.
Have,
Upon receiving the image formation request, the control means causes the fixing means to perform a preparatory operation, and the time required for the preparatory operation of the fixing means calculated by the calculation means is determined according to the content of the image formation. If the time required for the second preparatory operation is longer than the time required for the second preparatory operation, the image forming apparatus is characterized in that the first preparatory operation is stopped and the first preparatory operation is started after the preparatory operation of the fixing means. ..

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