JP2019191228A - Image formation apparatus - Google Patents

Abstract

To provide an image formation apparatus which can suppress the consumption of the time and service life of a member due to the re-execution of the preparation operation even when the preparation operation is suspended or finished in the image formation apparatus executing the preparation operation at the pre-start.SOLUTION: An image formation apparatus executes skip of ATVC control or shortening of the execution time of the ATVC control when executing the preparation operation again by properly taking over the result of executing the ATVC control in the preparation operation at the pre-start and the result of the ATVC control in accordance with the environmental change and the like after the ATVC control is finished.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an image forming apparatus such as a copying machine, a printer, or a facsimile apparatus using an electrophotographic system or an electrostatic recording system.

  Conventionally, for example, in an electrophotographic image forming apparatus, a toner image formed on an image carrier such as a photosensitive member or an intermediate transfer member is transferred onto a recording material by a transfer unit. As a transfer unit, a transfer member such as a transfer roller that forms a transfer portion in contact with an image carrier and transfers a toner image to a recording material by applying a transfer voltage is widely used.

  As a method for determining a transfer voltage during image formation, there is ATVC control (Active Transfer Voltage Control) (Patent Document 1). The ATVC control is generally performed as follows. Prior to image formation (more specifically, transfer), a current value flowing when a voltage is applied to the transfer member is detected, and a voltage value to be applied is adjusted so that the current value approaches a target value. By repeating this operation a plurality of times, the detected current value is converged to the target current value, and the transfer voltage at the time of image formation is determined.

  In addition, it is desirable for the image forming apparatus to shorten FPOT (First Print Out Time), which is the time until the first image is output. Patent Document 2 discloses a method for shortening the following FPOT. That is, when the printer controller receives a print command together with an image from an external device, the printer controller transmits an activation instruction for instructing a preparation operation to the engine control unit simultaneously with the start of image data processing (image development or the like). Thereby, the preparatory operation is executed during the processing of the image data. Thereafter, the printer controller transmits a print instruction for instructing the print operation to the engine control unit at the timing when the processing of the image data is completed. As a result, it is possible to shorten the FPOT by reducing the extra waiting time.

  Examples of the preparation operation include the start of heating of the fixing device, the start of rotation of the scanner motor, and the above-described ATVC control.

Patent No. 5815110 Japanese Patent No. 5355174

  However, after the activation instruction (first instruction) as described above is transmitted, the preparatory operation is performed before the print instruction (second instruction) is transmitted (also referred to as “pre-start” here). In this case, there are the following problems.

  During the pre-start, the operation started by the start instruction may be interrupted or terminated due to a time-out due to, for example, a cancel instruction by the operator or a time required for processing the image data. That is, the print instruction may not be transmitted to the engine control unit until all the operations started by the start instruction are completed. For example, when performing ATVC control during a preparatory operation, a print instruction may not be transmitted after the preparatory operation, or the user may cancel during the preparatory operation, and the preparatory operation may not end normally after executing the ATVC control. . In this case, the next time the print instruction is transmitted to the engine control unit, the preparatory operation is executed again. The print instruction transmitted to the engine control unit after the interruption or termination of the operation started by the start instruction is typically image data that has been canceled or timed out among a plurality of image data transmitted together with the print command. Includes different image data. For example, when image data related to multiple documents (documents, etc.) is included in one job executed by one print command, the image data of another document when one document is canceled or timed out is there.

  For this reason, in the conventional method, when the second preparation operation is executed, the same control (ATVC control or the like) as that at the pre-start is executed. This increases the time until the second preparation operation is completed. Further, the life of the member may be unnecessarily consumed, for example, the time for applying a high voltage to the photoreceptor may be lengthened and the life of the photoreceptor may be unnecessarily consumed.

  Accordingly, an object of the present invention is to suppress the consumption of time and the life of members in an image forming apparatus that performs a preparatory operation at a pre-start even if the preparatory operation is interrupted or terminated. It is an object of the present invention to provide an image forming apparatus that can do this.

  The above object is achieved by the image forming apparatus according to the present invention. In summary, the present invention relates to an image carrier on which an image is formed with toner, a transfer unit that transfers an image formed on the image carrier to a transfer target, and a transfer unit that performs transfer for the transfer. In an image forming apparatus having a power source for applying a voltage and a control unit that executes an adjustment operation for determining the transfer voltage before image formation, the control unit receives a first instruction, and receives a predetermined instruction. A first adjustment operation for determining the transfer voltage under the image forming conditions is started, and a second instruction including information relating to an image to be formed on the image carrier is input after the first instruction. Thus, it is possible to execute the second adjustment operation for determining the transfer voltage under the image forming condition corresponding to the information regarding the image included in the second instruction, and the first instruction is input. The second instruction is input from Whether or not to execute the second adjustment operation on the basis of at least one of the events up to and including the information about the image included in the second instruction, or the contents of the second adjustment operation The image forming apparatus is characterized in that a change is made.

  According to the present invention, in an image forming apparatus that performs a preparatory operation at the time of pre-start, even when the preparatory operation is interrupted or terminated, the consumption of time and member life due to the preparatory operation being performed again is suppressed. Can do.

1 is a schematic sectional view of an image forming apparatus. 2 is a block diagram of a control system of the image forming apparatus. FIG. It is a flowchart figure of control of Example 1. FIG. FIG. 6 is a timing chart illustrating an example of an operation based on control according to the first exemplary embodiment. It is a flowchart of control of Example 2. FIG. 10 is a timing chart illustrating an example of an operation by control according to the second embodiment. It is a table | surface for demonstrating an example of the shortening conditions of ATVC control.

  The image forming apparatus according to the present invention will be described below in more detail with reference to the drawings.

[Example 1]
1. Overall Configuration and Operation of Image Forming Apparatus FIG. 1 is a schematic cross-sectional view of an image forming apparatus 100 of the present embodiment. The image forming apparatus 100 according to the present exemplary embodiment is a laser beam printer using an electrophotographic method.

  The image forming apparatus 100 includes a photosensitive drum 1 that is a rotatable drum type (cylindrical) photosensitive member (electrophotographic photosensitive member) as an image carrier that carries a toner image. The photosensitive drum 1 is composed of an organic photoreceptor or an amorphous silicon photoreceptor. The photosensitive drum 1 is rotationally driven at a predetermined peripheral speed (process speed) in the arrow direction (clockwise) in the figure. The surface of the rotating photosensitive drum 1 is uniformly charged to a predetermined potential having a predetermined polarity (negative polarity in this embodiment) by a charging roller 2 which is a roller-type charging member as a charging unit. During the charging process, a predetermined charging voltage (charging bias) including a negative DC component is applied to the charging roller 2 from the charging power source 123 (FIG. 2).

  The surface of the charged photosensitive drum 1 is scanned and exposed by an exposure device (scanner unit) 3 as an exposure unit, and an electrostatic image (electrostatic latent image) is formed on the photosensitive drum 1. In this embodiment, image data of a target image is input to the image forming apparatus 100 from an image signal generating apparatus such as an image reading apparatus or a host computer. Then, the exposure apparatus 3 outputs a laser beam modulated (on / off converted) in accordance with exposure data (time-series electrical digital pixel signal) generated based on this image data. By irradiating the laser beam, scanning exposure of the surface of the photosensitive drum 1 is performed, and an electrostatic image corresponding to the image data is formed on the surface of the photosensitive drum 1. The scanning exposure start timing in the sub-scanning direction is notified from the image forming apparatus 100 to the image signal generating apparatus by a sub-scanning direction synchronization signal. The electrostatic image formed on the photosensitive drum 1 is developed (visualized) by supplying toner as a developer by a developing device 4 as developing means, and a toner image (developer image) is formed on the photosensitive drum 1. Is done. The developing device 4 includes a developing roller 4a as a developer carrying member that carries toner and conveys the toner to a portion facing the photosensitive drum 1 (developing portion). During the developing process, a predetermined developing voltage (developing bias) including a negative DC component is applied to the developing roller 4a from a developing power source (not shown).

  A transfer roller 5, which is a roller-type transfer member serving as transfer means, is disposed facing the photosensitive drum 1. The transfer roller 5 is urged toward the photosensitive drum 1 to form a transfer portion (transfer nip) N where the photosensitive drum 1 and the transfer roller 5 are in contact with each other. As described above, the toner image formed on the photosensitive drum 1 is transported while being sandwiched between the photosensitive drum 1 and the transfer roller 5 by the action of the transfer roller 5 in the transfer portion N. The recording material (sheet, transfer material) P is transferred. During the transfer process, the transfer roller 5 receives a DC voltage from the transfer power supply 132 (FIG. 2) having a polarity (positive polarity in this embodiment) opposite to the normal charging polarity of the toner (charging polarity during the developing process). A transfer voltage (transfer bias) is applied. That is, the transfer roller 5 supplies a charge having a polarity opposite to that of the toner from the back surface of the recording material P, thereby transferring the toner image from the photosensitive drum 1 to the recording material P. The recording material P is accommodated in the feeding tray 7 and is sent out from the feeding tray 7 by the feeding roller 8. Thereafter, the recording material P is conveyed to the transfer unit N by the registration roller 9 in timing with the toner image on the photosensitive drum 1.

  The recording material P to which the toner image has been transferred is separated from the photosensitive drum 1 and conveyed to a fixing device 10 as a fixing unit. The fixing device 10 includes a fixing heater 10a, a fixing film 10b, a pressure roller 10c, a thermistor 10c, and the like. The fixing device 10 heats and pressurizes the recording material P while transporting the recording material P, and fixes (melts and adheres) the toner image to the recording material P. The recording material P on which the toner image is fixed is conveyed by the discharge roller 11 and discharged (output) to the discharge tray 12.

  In the present embodiment, a top sensor 105 that detects the recording material P is disposed downstream of the registration rollers 9 and upstream of the transfer portion N in the conveyance direction of the recording material P. A discharge sensor 109 that detects the recording material P is disposed downstream of the fixing device 10 and upstream of the discharge roller 11 in the conveyance direction of the recording material P.

2. Next, the system configuration of the image forming apparatus 100 of this embodiment will be described. FIG. 2 is a block diagram for explaining the system configuration of the image forming apparatus 100 of the present embodiment.

  The image forming apparatus 100 includes an image controller unit 203 and an engine control unit 200. The engine control unit 200 includes a video interface unit 208, an image formation control unit 201, and a conveyance control unit 205. The image controller unit 203 can communicate with the host computer 204 and the engine control unit 200 which are external devices. The image formation control unit 201 includes a high voltage control unit 202, an exposure control unit 206, and a fixing control unit 210. For convenience, FIG. 2 also illustrates a transfer roller temperature estimation unit 211 provided in the image forming control unit 210 and a temperature sensor 131 provided in the image forming apparatus 100, which are described in the second embodiment.

  The host computer 204, which is an external device, transmits an image forming command to the image controller unit 203 of the image forming apparatus 100 together with image forming conditions and target image data. The image controller unit 203 converts the received image data into exposure data necessary for the image forming apparatus 100 and creates image formation reservation information for each recording material P based on the received image forming conditions. The image formation reservation information includes, for example, an image formation mode (for example, standard paper) in which image formation conditions are set according to the supply source (such as a feeding tray) of the recording material P, the size of the recording material P, the type of the recording material P, and the like. (Plain paper), thick paper, and thin paper modes). In addition, the image controller unit 203 synchronizes with the start of image data processing and creation of image formation reservation information, and a preparation operation instruction (first instruction) that is a signal for instructing the image formation control unit 201 to perform a preparation operation. ) Is transmitted to the engine control unit 200. The first instruction (first command) transmitted to the engine control unit 200 is transmitted to the image formation control unit 201 via the video interface unit 208. The transmission in synchronization with the creation of the image formation reservation information includes transmission at the same time as the start of the creation, or before and after the start of the creation for a sufficiently short time. Upon receiving the first instruction from the image controller unit 203, the image formation control unit 201 starts a preparation operation. Thereafter, when the conversion from the image data to the exposure data is completed, the image controller unit 203 instructs the image formation control unit 201 to start an image formation start, which is a signal instructing the start of an image formation operation (printing, printing, printing) (Second instruction) is transmitted to the engine control unit 200. The image controller unit 203 may transmit the second instruction when it is expected that the conversion from the image data to the exposure data is completed. The second instruction (second command) transmitted to the engine control unit 200 is transmitted to the image formation control unit 201 via the video interface unit 208. In this embodiment, it is assumed that the second instruction includes image formation reservation information created by the image controller unit 203 and exposure data as information relating to an image. The image formation reservation information and the exposure data may be transmitted sequentially or substantially simultaneously. Upon receiving the second instruction from the image controller unit 203, the image formation control unit 201 starts an image forming operation.

  The conveyance control unit 205 rotationally drives various rotating members of the image forming apparatus 100 by the conveyance motor 150. The conveyance motor 150 rotationally drives the feeding roller 8, the registration roller 9, the photosensitive drum 1, the transfer roller 5, the pressure roller 10 c, and the discharge roller 11. The conveyance control unit 205 controls the rotational drive of each control target based on the detection results of the top sensor 105 and the discharge sensor 109. The conveyance motor 150 and the feed roller 8 are connected via a feed clutch (not shown). When the recording material P is fed from the feeding tray 7, the feeding clutch is connected for a predetermined time, and the feeding roller 8 is driven to rotate.

  A high voltage control unit 202 of the image forming control unit 201 controls a power source that applies a DC voltage or an AC voltage to various voltage application members in the image forming apparatus 100, for example, the charging roller 2, the developing roller 4 a, and the transfer roller 5. Moreover, the high voltage | pressure control part 202 performs ATVC control. The ATVC control is executed as follows. The high voltage control unit 202 sets a voltage to be initially applied from the transfer power supply 132 to the transfer roller 5. Thereafter, the high voltage control unit 202 samples the current value flowing through the transfer roller 5 when the voltage is applied by the current detection unit 126 for a certain period of time. Then, the high voltage controller 202 compares the obtained current value with the target current value, and adjusts the voltage value applied from the transfer power supply 132 to the transfer roller 5 so that the obtained current value approaches the target current value. To do. In the ATVC control, this operation is repeated a predetermined number of times. Then, the detected current value is converged to the target current value, and the transfer voltage value at the time of image formation is finally determined. At this time, the value of the current flowing through the transfer roller 5 varies depending on the temperature of the transfer roller 5 in addition to the output of the transfer power supply 132. The target current value is changed according to image forming conditions such as process speed during image formation and the type of recording material P used for image formation. The transfer voltage value at the time of image formation may be a voltage value finally adjusted in the ATVC control, or a voltage value obtained by performing a predetermined calculation based on the voltage value. May be. In this embodiment, as the target current value, a target current value at the time of image formation that is set in advance according to the image forming conditions is set, and the voltage value that is finally adjusted in the ATVC control is used as the target current value. It is determined as the transfer voltage value at the time.

  The exposure control unit 206 of the image formation control unit 201 controls the rotation of a scanner motor (not shown) of the exposure apparatus 3 and the correction of the exposure light quantity. Based on the exposure data received from the image controller unit 203, the photosensitive drum 1 is controlled.

  The fixing control unit 211 of the image formation control unit 201 detects the surface temperature of the fixing heater 10a by the thermistor 10d, and controls power supply to the fixing heater 10a based on the detection result.

3. Preparation Operation Next, the preparation operation in the present embodiment will be described. FIG. 3 is a flowchart illustrating processing in which the engine control unit 200 (more specifically, the image formation control unit 201 of the engine control unit 200) operates according to the control program. Reference numerals such as S101 in the flowcharts indicate step numbers. FIG. 4 is a timing chart in an example of an operation when the process of FIG. 3 is executed. FIG. 4A shows a case where ATVC control is executed in a preparatory operation at the time of pre-rotation described later, and FIG. 4B shows a case where ATVC control is not executed in a preparatory operation at the time of pre-rotation described later.

  The engine control unit 200 transmits an image formation command together with image formation conditions and image data from the host computer 204 to the image controller unit 203 by an operation of an operator such as a user, and the subsequent steps in S101 and thereafter in FIG. Start processing. As shown in FIG. 3A, the engine control unit 200 receives a first instruction (preparation operation instruction) from the image controller unit 203 (S101). The timing for receiving the first instruction corresponds to the timing t101 in FIGS. 4 (a) and 4 (b). When receiving the first instruction, the engine control unit 200 starts a preparatory operation at the time of pre-start (S102).

  FIG. 3B is a flowchart of the pre-start preparation operation (first preparation operation) executed in S102 of FIG. 3A. In the preparatory operation at the time of pre-start, driving of the conveyance motor 150 is started (S120), driving of the fixing heater 10a is started (S121), and ATVC control is started (S122). At this time, the engine control unit 200 cannot yet determine what image formation conditions the image formation to be performed next will be, so that each of the operations described above is a standard setting (for example, A4 size, the image formation mode is the standard paper mode) Etc.).

  As shown in FIG. 3A, the engine control unit 200 determines whether or not a second instruction (image formation start instruction) has been transmitted from the image controller 203 after starting the preparatory operation at the time of pre-start. (S103). If it is determined in S103 that the second instruction has been transmitted, the engine control unit 200 starts a preparatory operation during the previous rotation (S106).

  On the other hand, when it is determined in S103 that the second instruction has not been transmitted, the engine control unit 200 waits until the second instruction is transmitted (S104, S105). During this standby, the engine control unit 200 waits for a timeout of the operation started by the first instruction (preparation operation at the time of pre-start) or a cancel instruction from the image controller unit 203. If there is a timeout or cancel instruction, the engine control unit 200 waits until a second instruction is transmitted from the image controller 203 (S105). The timing at which this timeout or cancel instruction is given corresponds to the timing t104 in FIGS. 4 (a) and 4 (b). When the second instruction is transmitted from the image controller unit 201, the engine control unit 200 executes a preparatory operation at the time of pre-rotation (S106). The timing for starting the preparatory operation during the pre-rotation corresponds to the timing t105 in FIGS. 4 (a) and 4 (b).

  As described above, the image controller unit 203 transmits the first instruction to the engine control unit 200 after receiving the image forming command from the host computer 204 by the operation of the operator. The first instruction is a signal for notifying that the image formation has been instructed, and is a signal for instructing the start of the preparation operation. Further, the image controller unit 203 transmits a second instruction to the engine control unit 200 when the processing of the image data received from the host computer 204 together with the image formation command is completed (or when the completion is expected). The second instruction is a signal for informing that it is possible to start transmission of an image signal (exposure data) after the image controller unit 203 interprets the content of the image forming command, and the image forming operation Is a signal instructing the start of In the following case, the image controller unit 203 transmits to the engine control unit 200 an instruction (stop instruction) for stopping (interrupting or ending) the operation started by the first instruction (preparation operation at the time of pre-start). To do. That is, this is a case where an instruction for canceling an image forming command is received from the host computer 204 by a user operation before transmitting the second instruction after transmitting the first instruction. When the stop instruction is transmitted, the engine control unit 200 stops (suspends or ends) the operation started by the first instruction. The engine control unit 200 also stops (suspends or ends) the operation started by the first instruction also in the following case. That is, when the time taken to process image data by the image controller unit 203 exceeds a predetermined time (timeout) before the second instruction is transmitted after the first instruction is transmitted. It is. The second instruction transmitted to the engine control unit 200 after the interruption or termination of the operation started by the first instruction is typically a cancel or timeout among a plurality of image data transmitted together with the image formation command. This includes image data different from the image data in which the image is generated. For example, when image data related to a plurality of documents (documents, etc.) is included in one job executed by one image forming command, image data of another document when cancellation or timeout occurs for one document, etc. It is.

  FIG. 3C is a flowchart of the preparatory rotation preparation operation (second preparation operation) executed in S106 of FIG. 3A. In the preparatory operation at the time of pre-rotation, the driving of the conveyance motor 150 is started (S123), the driving of the fixing heater 10a is started (S124), and the ATVC control is skipped when the predetermined condition is satisfied, and is not satisfied In this case, ATVC control is executed (S125, S126). The difference between the pre-start preparation operation and the pre-rotation preparation operation is that the conveyance motor 150 and the fixing heater 10a are driven with settings according to the contents of the second instruction, and ATVC control skipping. This is the point of making a judgment. Note that the content of the second instruction is specifically an image forming mode (for example, each mode of standard paper (plain paper), thick paper, and thin paper) for setting image forming conditions included in the second instruction. Information. In this embodiment, roughly, when the pre-start preparation operation is interrupted or terminated (when the second instruction is not transmitted until the pre-start preparation operation is completed), the following Take control. That is, control is performed to skip the ATVC control according to the time from the end of the ATVC control in the preparatory operation at the pre-start to the time when the second instruction is transmitted and the content of the second instruction. The ATVC control is skipped when the ATVC control in the preparatory preparatory operation has been completed (when the prestart preparatory operation has been interrupted or terminated after the ATVC control in the prestart preparatory operation has been completed). be able to.

In this embodiment, the engine control unit 200 determines that the condition for skipping ATVC control in the preparatory operation during the pre-rotation is satisfied when all of the following conditions 1 to 3 are satisfied.
Condition 1: ATVC control ends during pre-start preparation operation Condition 2: Time from the end of ATVC control in pre-start preparation operation until the second instruction is transmitted is less than a predetermined time Condition 3: The content of the second instruction is the same as the content assumed in the pre-start preparation operation (specifically, the target current value is the same)

  The above conditions 1 to 3 are provided for the following reason.

  Condition 1 is because the ATVC control result cannot be used unless the ATVC control is completed at the time of S125. Note that the timing at which the ATVC control is completed can be represented by the timing (application start timing, application end timing, and the like) at which the voltage is applied at the voltage value last adjusted in one ATVC control.

  Condition 2 is that the state of the image forming apparatus 100 (environmental temperature and transfer roller 5 condition) is exceeded when the time from the end of the ATVC control in the preparatory operation at the end of the pre-start until the second instruction is transmitted elapses for a predetermined time. Temperature, etc.) may change. When the state of the image forming apparatus 100 changes, there is a high possibility that the result of ATVC control will change. Therefore, in this embodiment, in this case, the result of ATVC control in the preparatory operation at the pre-start is not used. There is a possibility that the state of the image forming apparatus 100 does not change even after a certain time has elapsed. However, in this embodiment, priority is given to obtaining the result of the ATVC control according to the state of the image forming apparatus 100 more reliably, and in this case, the ATVC control in the preparatory operation during the previous rotation is not skipped. Note that the time from the end of ATVC control in the preparatory operation at the time of the pre-start until the second instruction is transmitted is the second instruction after the first instruction is transmitted, which correlates with the time. The time until transmission can be substituted. Here, the timing at which the instruction is transmitted (or input) can be represented by the timing at which the transmission (or input) of the instruction starts or ends.

  Condition 3 is an image forming condition assumed in the preparatory operation at the time of pre-start (for example, a target current value corresponding to the type of recording material P, process speed, etc.) and an image forming condition specified by the second instruction. This is because the results of ATVC control are different when. For example, in the second instruction, a process speed different from the process speed of the standard image forming condition assumed in the preparatory operation at the time of pre-start is designated. When the ATVC control is skipped, the engine control unit 200 uses the result of the ATVC control executed in the preparatory operation at the prestart. That is, the setting of the transfer voltage at the time of image formation acquired in the preparatory operation at the time of pre-start is determined as the transfer voltage at the time of subsequent image formation.

  As shown in FIG. 3A, after starting the preparatory operation during the pre-rotation, the engine control unit 200 waits until all the preparatory operations are completed (S107). When all the preparation operations are completed, the engine control unit 200 executes an image forming operation (S108). The timing for starting this image forming operation corresponds to the timing t108 in FIGS. 4 (a) and 4 (b). Thereafter, the engine control unit 200 ends the operation of the image forming apparatus 100 when the image forming operation ends.

  As described above, according to the present embodiment, when the second instruction is transmitted after the preparatory operation at the time of pre-start is interrupted or terminated, the control for skipping the ATVC control is performed. Thereby, it is possible to reduce the time of the operation after the second instruction is transmitted by reducing the execution time of the ATVC control in the preparatory operation due to the transmission of the second instruction. . Thereby, the high voltage application time to the photosensitive drum 1 can be shortened, and unnecessary consumption of the life of the photosensitive drum 1 can be suppressed.

[Example 2]
Next, another embodiment of the present invention will be described. The basic configuration and operation of the image forming apparatus according to the present exemplary embodiment are the same as those of the image forming apparatus according to the first exemplary embodiment. Accordingly, in the image forming apparatus according to the present embodiment, elements having the same or corresponding functions or configurations as those of the image forming apparatus according to the first embodiment are denoted by the same reference numerals as those in the first embodiment, and detailed description thereof is omitted. To do.

  In the first embodiment, when the second instruction is transmitted after the pre-start preparatory operation is interrupted or terminated, the control for skipping the ATVC control is performed. In this embodiment, instead of the control for skipping the ATVC control, the ATVC control is skipped or the control for executing the shortened ATVC control having a shorter execution time than the normal (ATVC control in the preparatory operation at the pre-start) is performed. .

  FIG. 5 is a flowchart illustrating a process in which the engine control unit 200 (more specifically, the image formation control unit 201 of the engine control unit 200) operates according to the control program in the present embodiment. In FIG. 5, the same steps as those in the first embodiment shown in FIG. In this embodiment, the preparatory operation process at the pre-start is the same as the process in the first embodiment shown in FIG. 3B, and therefore the flowchart of this process is omitted in FIG. FIG. 6 is a timing chart in an example of an operation when the processing of FIG. 5 is executed. This figure shows a case where the shortened ATVC control is executed in the preparatory operation during the pre-rotation. Timing charts when normal ATVC control is executed in the preparatory operation during the pre-rotation and when ATVC control is not executed are the same as those in the first embodiment shown in FIGS. 4A and 4B, respectively. Therefore, it is omitted.

  The engine control unit 200 transmits an image formation command together with image formation conditions and image data from the host computer 204 to the image controller unit 203 by an operation of an operator such as a user, and the subsequent steps in S101 and thereafter in FIG. Start processing. Since the processing from S101 to S105 in FIG. 5A is the same as that in the first embodiment, description thereof is omitted. In the present embodiment, in S201, the engine control unit 200 executes a preparatory operation at the time of pre-rotation. The timing for starting the preparatory operation during the pre-rotation corresponds to the timing t201 in FIG.

  FIG. 5B is a flowchart of the preparatory rotation preparation operation (second preparation operation) executed in S201 of FIG. 5A. Since the processing of S123 to S126 in FIG. 5B is the same as that of the first embodiment, description thereof is omitted. In this embodiment, when it is determined in S125 that the condition for skipping the ATVC control in the preparatory operation at the time of the previous rotation is not satisfied, the engine control unit 200 sets the condition for executing the shortened ATVC control instead of the normal ATVC control. It is determined whether it is satisfied (S202). If it is determined in S202 that the conditions for executing the shortened ATVC control are satisfied, the engine control unit 200 executes the shortened ATVC control (S203). If it is determined in S202 that the conditions for executing the shortened ATVC control are not satisfied, the engine control unit 200 executes the normal ATVC control as in the first embodiment (S126).

In the present embodiment, the engine control unit 200 satisfies both the conditions 1 and 2 among the following conditions 1 to 3 and satisfies at least one of the conditions 3 and 4; It is determined that the conditions for executing the shortened ATVC control are satisfied in the preparation operation. When all of the conditions 1 to 4 are satisfied, it may be determined that the condition for executing the shortened ATVC control is satisfied in the preparatory operation during the previous rotation.
Condition 1: ATVC control ends during pre-start preparation operation Condition 2: Time from the end of ATVC control in pre-start preparation operation until the second instruction is transmitted is less than a predetermined time Condition 3: Condition in which the difference between the content of the second instruction and the content assumed in the preparatory operation at the pre-start is within a predetermined range (specifically, the difference in target current value is less than a predetermined amount) 4: The temperature change of the transfer roller 5 from the end of the ATVC control in the preparatory operation at the pre-start until the second instruction is transmitted is less than a predetermined value.

  The above conditions 1 to 4 are provided for the following reason.

  The conditions 1 and 2 are the same reason as in the case of skipping the ATVC control described in the first embodiment, and thus the description thereof is omitted.

  Condition 3 is that the ATVC control result basically changes when the target current value is different, but the difference in the result is reduced when the difference in the target current value is small.

  Condition 4 is that the ATVC control result basically changes when the electrical resistance of the transfer roller 5 fluctuates depending on the temperature of the transfer roller 5. However, when the temperature change is small, the difference in the result becomes small as in condition 3. is there. Examples of a method for estimating the temperature of the transfer roller 5 include a method using an environmental temperature and a method estimating from the number of images formed. In this embodiment, as shown in FIG. 2, the temperature of the transfer roller 5 is estimated by the transfer roller temperature estimation unit 211 provided in the image formation control 201 of the engine control unit 200. In the present exemplary embodiment, the transfer roller temperature estimation unit 211 is configured to set the environment temperature set in advance and the transfer roller 5 based on the detection result of the temperature sensor 131 (FIG. 2) provided in the apparatus main body of the image forming apparatus 100. The temperature of the transfer roller 5 is estimated with reference to the relationship with the temperature. In this embodiment, the temperature sensor 131 detects the temperature in the apparatus main body of the image forming apparatus 100 as the environmental temperature. The temperature sensor 131 is an example of an environment detection unit that detects at least one of temperature and humidity inside or outside the image forming apparatus 100. As the temperature change of the transfer roller 5 from the end of the ATVC control in the preparatory operation at the time of pre-start until the second instruction is transmitted, the first instruction correlated with the temperature change is transmitted. Until the second instruction is transmitted. Alternatively, a change in temperature from when the first instruction is transmitted to when the execution of the shortened ATVC control is determined may be substituted.

  When the conditions for executing the shortened ATVC control are satisfied, the transfer voltage value obtained when the ATVC control is executed is less different from the transfer voltage value obtained by the ATVC control in the preparatory operation at the pre-start. Become. Therefore, when executing the shortened ATVC control, the voltage value first applied to the transfer roller 5 is set to the transfer voltage value obtained at the time of the previous ATVC control (ATVC control in the preparatory operation at the pre-start). In this case, as compared with the case where the voltage value first applied to the transfer roller 5 is set to a preset standard voltage value as in normal ATVC control, the difference between the current value detected first and the target current value is different. Becomes smaller. Therefore, the number of adjustments of the voltage value necessary to reach the target current value can be reduced. In this embodiment, the number of adjustments of the voltage value is reduced in this way (for example, if the target current value change amount is within 10%, half the number of times of the conventional method), the ATVC control execution time is shortened from the normal ATVC control execution time. Reduce execution time.

  In the present embodiment, the degree to which the number of adjustments of the voltage value is reduced by one in the shortened ATVC control than in the normal ATVC control is made one. On the other hand, for example, as shown in FIG. 7, a plurality of degrees of reducing the number of adjustments of the voltage value (degrees of shortening the execution time of the ATVC control) may be provided by combining a plurality of conditions. In the example shown in FIG. 7, the adjustment is performed according to the amount of change in the target current value corresponding to the second instruction from the target current value corresponding to the preparatory operation at the pre-start and the amount of change in the temperature of the transfer roller 5. The degree to reduce the number of times has been changed. In other words, the amount of decrease in the number of adjustments is increased as the amount of change in the target current value decreases, and the amount of decrease in the number of adjustments is increased as the amount of change in the temperature of the transfer roller 5 decreases. The number of adjustments (amount of reduction in ATVC control execution time) may be changed according to any one of these conditions.

  Since the processes in S107 and S108 in FIG. 5A are the same as those in the first embodiment, description thereof is omitted.

  As described above, according to the present embodiment, when the second instruction is transmitted after the pre-start preparation operation is interrupted or completed, the ATVC control is skipped or the ATVC control execution time is shortened. Take control. As a result, it is possible to reduce or shorten the execution time of the ATVC control in the preparatory operation due to the transmission of the second instruction. Therefore, according to the present embodiment, it is possible to shorten the operation time after the second instruction is transmitted under conditions wider than those of the first embodiment. Thereby, the high voltage application time to the photosensitive drum 1 can be shortened, and unnecessary consumption of the life of the photosensitive drum 1 can be suppressed.

  As described above, the image forming apparatus 100 according to the present invention has the control unit 200 that executes the adjustment operation (ATVC control) for determining the transfer voltage before the image formation. When the first instruction is input, the control unit 200 starts a first adjustment operation for determining a transfer voltage under a predetermined image forming condition. Further, the control unit 200 receives the second instruction including the information related to the image to be formed on the image carrier 1 after the first instruction, thereby corresponding to the information regarding the image included in the second instruction. It is possible to execute the second adjustment operation for determining the transfer voltage under the image forming conditions. Then, the control unit 200 is based on at least one of an event from when the first instruction is input to when the second instruction is input, and information regarding the image included in the second instruction. Whether or not to execute the second adjustment operation or the content of the second adjustment operation is changed. More specifically, the control unit 200 can change whether or not to execute the second adjustment operation or the content of the second adjustment operation based on at least one of the following. First, it is whether or not the first adjustment operation is completed before the second instruction as the event is input. Second, it is the time from the end of the first adjustment operation as the event until the second instruction is input. Third, there is a change in the index value that correlates with the temperature of the transfer means 5 between the end of the first adjustment operation as the above event and the input of the second instruction. Fourth, there is an image forming condition corresponding to information regarding the image included in the second instruction. In the above-described embodiment, whether or not the ATVC control is executed or whether or not the shortened ATVC control is possible is determined depending on whether or not a condition obtained by combining some of the above conditions is satisfied. However, the present invention is not limited to this, and each of the above conditions may be used independently for determining whether or not the ATVC control is executed or whether or not the shortened ATVC control is possible depending on the accuracy of the desired ATVC control. Any combination may be used.

  Here, when the first adjustment operation is not completed before the second instruction is input, the control unit 200 executes the second adjustment operation and determines the transfer determined by the second adjustment operation. The voltage is a transfer voltage at the time of image formation. In addition, the control unit 200 does not execute the second adjustment operation when the time from when the first adjustment operation is completed until the second instruction is input is less than a predetermined time, The transfer voltage determined by the above is used as the transfer voltage at the time of image formation (second adjustment operation is skipped). Alternatively, in this case, the transfer voltage determined by the second adjustment operation by executing the second adjustment operation that is completed in a shorter time than the first adjustment operation can be used as the transfer voltage at the time of image formation ( Perform a shortened second adjustment operation). In addition, when the change in the index value correlated with the temperature of the transfer unit 5 between the end of the first adjustment operation and the input of the second instruction is less than a predetermined value, the control unit 200 The second adjustment operation may be skipped or a shortened second adjustment operation may be executed. In addition, the control unit 200 determines whether the second image forming condition corresponding to the information related to the image included in the second instruction is the same as the predetermined image forming condition or the difference satisfies the predetermined condition. The adjustment operation may be skipped or a shortened second adjustment operation may be performed. This is possible when the first adjustment operation is completed before the second instruction is input. The case where the difference satisfies the predetermined condition is typically a case where the difference in the target current value in the ATVC control is less than the predetermined value. In addition, when the control unit 200 executes the second adjustment operation that ends in a shorter time than the first adjustment operation, the control unit 200 can perform the following. That is, the time for shortening the time required for the second adjustment operation relative to the time required for the first adjustment operation corresponds to the index value correlated with the temperature of the transfer unit and the information related to the image included in the second instruction. It is possible to change based on at least one of the image forming conditions.

[Others]
As mentioned above, although this invention was demonstrated according to the specific Example, this invention is not limited to the above-mentioned Example.

  In the above-described embodiments, the image forming apparatus is a monochromatic image forming apparatus. However, the present invention can also be applied to a color image forming apparatus. For example, as a color image forming apparatus, a toner image formed on a first image carrier such as a plurality of photosensitive drums is first transferred onto a second image carrier such as an intermediate transfer belt, and then the second image carrier is used. An intermediate transfer system that performs secondary transfer from an image carrier to a recording material is well known. In an intermediate transfer type image forming apparatus, a primary transfer voltage is applied to a primary transfer member that forms a primary transfer portion in contact with a first image carrier through a second image carrier, and the primary transfer voltage is applied. Transcription is often performed. Further, in an intermediate transfer type image forming apparatus, secondary transfer is often performed by applying a secondary transfer voltage to a secondary transfer member that forms a secondary transfer portion in contact with a second image carrier. . In such an image forming apparatus, the transfer voltage (primary transfer voltage or secondary transfer voltage) may be determined by ATVC control in at least one of the primary transfer portion and the secondary transfer portion. Therefore, in such an image forming apparatus, the present embodiment can be applied to ATVC control in at least one of the primary transfer portion and the secondary transfer portion, and the same effect as the above-described embodiment can be obtained. .

DESCRIPTION OF SYMBOLS 1 Photosensitive drum 5 Transfer roller 100 Image forming apparatus 132 Transfer power supply 200 Engine control part 203 Image controller part

Claims (12)

An image carrier on which an image is formed with toner;
Transfer means for transferring an image formed on the image carrier to a transfer target;
A power supply for applying a transfer voltage for the transfer to the transfer means;
A control unit that executes an adjustment operation for determining the transfer voltage before image formation;
In an image forming apparatus having
When the first instruction is input, the control unit starts a first adjustment operation for determining the transfer voltage under a predetermined image forming condition. After the first instruction, the image carrier When a second instruction including information relating to the image to be formed is input, a second adjustment operation for determining the transfer voltage under an image forming condition corresponding to the information relating to the image included in the second instruction is performed. At least one of an event from when the first instruction is input to when the second instruction is input, and information regarding an image included in the second instruction. The image forming apparatus according to claim 1, wherein the second adjustment operation is executed or the content of the second adjustment operation is changed.   The control unit determines whether or not the first adjustment operation has been completed before the second instruction as the event is input, and the first adjustment operation as the event has been completed. The time from when the second instruction is input to the control unit until the second instruction is input to the control unit from the end of the first adjustment operation as the event Whether to execute the second adjustment operation based on at least one of a change in index value correlated with the temperature of the transfer unit and an image forming condition corresponding to information on the image included in the second instruction 2. The image forming apparatus according to claim 1, wherein the content of the second adjustment operation is changed.   When the first adjustment operation is not completed by the time the second instruction is input, the control unit executes the second adjustment operation and determines the second adjustment operation by the second adjustment operation. The image forming apparatus according to claim 2, wherein the transfer voltage is the transfer voltage at the time of image formation.   The control unit does not execute the second adjustment operation when the time from the end of the first adjustment operation to the input of the second instruction is less than a predetermined time. The transfer voltage determined by the adjustment operation is used as the transfer voltage at the time of image formation, or the second adjustment operation that is completed in a shorter time than the first adjustment operation is executed to execute the second adjustment operation. The image forming apparatus according to claim 2, wherein the transfer voltage determined by the step is used as the transfer voltage at the time of image formation.   When the change in the index value correlated with the temperature of the transfer unit between the end of the first adjustment operation and the input of the second instruction is less than a predetermined value, the control unit The transfer voltage determined by the first adjustment operation without executing the second adjustment operation is set as the transfer voltage at the time of image formation, or the second adjustment is completed in a shorter time than the first adjustment operation. 5. The image forming apparatus according to claim 2, wherein the transfer voltage determined by the second adjustment operation by executing the adjustment operation is used as the transfer voltage at the time of image formation. 6. .   The control unit has completed the first adjustment operation until the second instruction is input, and the image forming condition corresponding to the information relating to the image included in the second instruction and the predetermined image The second adjustment is performed when the formation conditions are the same or the difference between the image formation conditions corresponding to the information related to the image included in the second instruction and the predetermined image formation conditions satisfies a predetermined condition. The transfer voltage determined by the first adjustment operation without executing the operation is used as the transfer voltage at the time of image formation, or the second adjustment operation is completed in a shorter time than the first adjustment operation. 6. The image forming apparatus according to claim 2, wherein the transfer voltage that is executed and determined by the second adjustment operation is used as the transfer voltage at the time of image formation.   When the control unit executes the second adjustment operation that is completed in a shorter time than the first adjustment operation, the control unit sets the time required for the second adjustment operation to the time required for the first adjustment operation. The time to be shortened can be changed based on at least one of an index value correlating with the temperature of the transfer unit and an image forming condition corresponding to information on the image included in the second instruction. The image forming apparatus according to claim 2, wherein the image forming apparatus is an image forming apparatus. An image carrier on which an image is formed with toner;
Transfer means for transferring an image formed on the image carrier to a transfer target;
A power supply for applying a transfer voltage for the transfer to the transfer means;
A control unit that executes an adjustment operation for determining the transfer voltage before image formation;
In an image forming apparatus having
The controller is
When the first instruction is input, a first adjustment operation for determining the transfer voltage under a predetermined image forming condition is started, and the image formed on the image carrier after the first instruction is related to By inputting the second instruction including information, it is possible to execute the second adjustment operation for determining the transfer voltage under the image forming conditions corresponding to the information regarding the image included in the second instruction. And
The first adjustment operation is completed by the time the second instruction is input, and a time period from when the first adjustment operation is completed until the second instruction is input is predetermined. If the image forming condition corresponding to the information relating to the image included in the second instruction is less than the time and the predetermined image forming condition is the same, the second adjustment operation is not executed and the first adjustment operation is not performed. An image forming apparatus characterized in that the transfer voltage determined by the adjustment operation is used as the transfer voltage at the time of image formation. An image carrier on which an image is formed with toner;
Transfer means for transferring an image formed on the image carrier to a transfer target;
A power supply for applying a transfer voltage for the transfer to the transfer means;
A control unit that executes an adjustment operation for determining the transfer voltage before image formation;
In an image forming apparatus having
The controller is
When the first instruction is input, a first adjustment operation for determining the transfer voltage under a predetermined image forming condition is started, and the image formed on the image carrier after the first instruction is related to By inputting the second instruction including information, it is possible to execute the second adjustment operation for determining the transfer voltage under the image forming conditions corresponding to the information regarding the image included in the second instruction. And
The first adjustment operation is completed by the time the second instruction is input, and a time period from when the first adjustment operation is completed until the second instruction is input is predetermined. If the image forming condition corresponding to the information relating to the image included in the second instruction is less than the time and the predetermined image forming condition is the same, the second adjustment operation is not executed and the first adjustment The transfer voltage determined by the adjustment operation is the transfer voltage at the time of image formation,
The first adjustment operation is completed by the time the second instruction is input, and a time period from when the first adjustment operation is completed until the second instruction is input is predetermined. When the difference between the image forming condition corresponding to the information related to the image included in the second instruction and the predetermined image forming condition is less than the time and satisfies the predetermined condition, it is shorter than the first adjustment operation An image forming apparatus, wherein the transfer voltage determined by the second adjustment operation by executing the second adjustment operation that ends in time is used as the transfer voltage at the time of image formation. An image carrier on which an image is formed with toner;
Transfer means for transferring an image formed on the image carrier to a transfer target;
A power supply for applying a transfer voltage for the transfer to the transfer means;
A control unit that executes an adjustment operation for determining the transfer voltage before image formation;
In an image forming apparatus having
The controller is
When the first instruction is input, a first adjustment operation for determining the transfer voltage under a predetermined image forming condition is started, and the image formed on the image carrier after the first instruction is related to By inputting the second instruction including information, it is possible to execute the second adjustment operation for determining the transfer voltage under the image forming conditions corresponding to the information regarding the image included in the second instruction. And
The first adjustment operation is completed by the time the second instruction is input, and a time period from when the first adjustment operation is completed until the second instruction is input is predetermined. If the image forming condition corresponding to the information relating to the image included in the second instruction is less than the time and the predetermined image forming condition is the same, the second adjustment operation is not executed and the first adjustment operation is not performed. The transfer voltage determined by the adjustment operation is the transfer voltage at the time of image formation,
The first adjustment operation is completed by the time the second instruction is input, and a time period from when the first adjustment operation is completed until the second instruction is input is predetermined. When the change of the index value correlated with the temperature of the transfer means between the end of the first adjustment operation and the input of the second instruction is less than a predetermined value. An image characterized in that the transfer voltage determined by the second adjustment operation is set as the transfer voltage at the time of image formation by executing the second adjustment operation that ends in a shorter time than the first adjustment operation. Forming equipment. When the image forming command is received, the first instruction is transmitted to the control unit, the image data received together with the image forming command is processed, and the image forming command can be started. An image controller unit that transmits the second instruction, wherein the image forming instruction is canceled after the first instruction is transmitted to the control unit and before the second instruction is transmitted to the control unit. An image controller unit that transmits to the control unit a stop instruction to stop the operation started by the control unit according to the first instruction when a cancel instruction is received.
When the control unit stops the operation started by the first instruction after the stop instruction is transmitted before the operation started by the first instruction is completed, the second instruction 11. The control according to claim 1, wherein when the input is performed, control is performed to execute the second adjustment operation or to change a content of the second adjustment operation. Image forming apparatus. When the image forming command is received, the first instruction is transmitted to the control unit, the image data received together with the image forming command is processed, and the image forming command can be started. An image controller unit for transmitting the second instruction;
The control unit stops the operation started by the first instruction after the time required for the processing exceeds a predetermined time, and when the second instruction is next input, 11. The image forming apparatus according to claim 1, wherein control is performed to determine whether or not to perform the adjustment operation or to change a content of the second adjustment operation. 11.

Images