JP2009010602A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the lifetime of an image forming apparatus even though printing efficiency is improved when continuous printing is changed to intermittent printing in the image forming apparatus. <P>SOLUTION: An interval time from the end of forming an electrostatic latent image to an instruction to form the next electrostatic latent image is measured. When the interval time is equal to or more than a fixed time, the interval time is excluded from average calculation because of not being continuous printing. The average of interval times is calculated in each image reading mode. When a driving state maintaining time for continuous printing ends, waiting is performed during driving at a speed lower than usual only for a time 1. 8 times as long as an average interval time. If the next printing request comes during this period, printing is quickly performed because an initializing time is short. When a waiting time ends, a stop state being the same as the conventional manner comes. Since operation is performed at a low speed during waiting, the lifetime of the apparatus is not shortened. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an image forming apparatus, and more particularly to an image forming apparatus using an electrophotographic process such as a copying machine, a printer, or a facsimile.

  In recent years, low-cost inkjet printers have become popular in general households. Laser printers are also becoming popular in ordinary households. In an ink jet printer, since printing and conveyance are performed using a stepping motor, it is possible to pause during printing and wait for print data. Therefore, there is no particular problem even if the printing interval time is free. On the other hand, laser printers use DC motors and are difficult to pause. If the print interval time is free and the intermittent operation is performed, the printing efficiency is lowered, and the number of start / stops is increased to shorten the life of the apparatus. Even if it is driven to avoid it, the life of the apparatus is shortened.

  In a laser printer, various methods have been proposed in order to prevent the apparatus life from being shortened while quick start-up. For example, there is a method of waiting in a medium speed operation. Also, when copying multiple pages in a copy operation using a pressure plate, the document replacement time differs for each user, so all the document images are read into the large-capacity HDD or memory installed in the printer and then output to the printer. Therefore, continuous printing is performed. Below are some examples of prior art related to this.

  The “image writing device” disclosed in Patent Document 1 reduces power consumption, heat generation, and noise, extends the life of the scanner motor, and shortens the waiting time from the rest to the start of writing. During standby, the scanner motor is rotated at high speed. The scanner motor is rotated at a medium speed for a certain period of time after the standby time has elapsed. Thereafter, the scanner motor is rotated at a low speed. Change the high-speed rotation time and medium-speed rotation time according to the copy frequency.

  The “image forming apparatus” disclosed in Patent Document 2 shortens the first copy time while preventing consumption of the polygon motor in the final order. A polygon mirror is provided for each color image forming unit. When the image formation notice signal is received, the polygon mirror of each image forming unit other than the final order is activated. When the copy start signal is received, the polygon mirror of the image forming unit in the final order is activated. The consumption of the final polygon motor can be suppressed.

The “image forming apparatus” disclosed in Patent Document 3 can shorten the switching time of the color / monochrome mode while extending the life. When the monochrome mode is selected, the operations of the C, M, and Y photoconductors are stopped. The C, M, and Y laser diodes are turned off. The motor that drives the C, M, and Y polygon mirrors is rotated. When switching to the color mode, image formation can be performed quickly.
Japanese Patent Laid-Open No. 05-080642 JP 2005-225157 A Japanese Unexamined Patent Publication No. 2007-010858

  However, the conventional printing method has the following problems. Due to the relationship between the preparation time of image data and the printing time, even when the user instructs continuous printing, the printer engine may be intermittently operated repeatedly to start and stop, which may reduce printing efficiency. Further, since a low-cost multifunction peripheral cannot read all original images into a memory, even if continuous printing is desired, actual printing is intermittent.

  SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional problems and prevent an apparatus life from being shortened while improving the efficiency of continuous printing in an image forming apparatus having a small image memory.

  In order to solve the above-described problems, in the present invention, an image reading unit that reads image data of a document, an image processing unit that converts image data read by the image reading unit into print image data, and print image data A writing unit that projects light onto the photoconductor to form an electrostatic latent image, a developing unit that converts the electrostatic latent image into a visible image with toner, and a visible image of the toner directly or via an intermediate transfer member. Interval time measurement that measures the interval time from the end of electrostatic latent image formation to the next electrostatic latent image formation instruction in an image forming apparatus that has a transfer means for transferring to printing paper and that forms an image by an electrophotographic process Means, an average calculating means for calculating an average interval time of the interval time, and an extending means for setting the standby state for a predetermined time of the average interval time after the end of the normal operation state.

  The extension means includes means for controlling the drive motor to drive at a lower speed than in the normal operation state. The average calculation means includes means for excluding an interval time longer than the predetermined time from the calculation of the average interval time. The image reading means includes an original conveying means for conveying the originals one by one from the original bundle to the image reading position and reading the image data. The image forming apparatus includes a FAX receiving unit that receives image data via an external communication line, and the image processing unit includes a unit that converts image data from the FAX receiving unit into image data for printing. The average calculating means includes means for calculating an average interval time for each type and mode of image reading.

  By configuring as described above, it is possible to improve the efficiency of continuous printing while preventing the life of the image forming apparatus from being shortened.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to FIGS.

  The embodiment of the present invention measures the interval time from the end of electrostatic latent image formation to the next electrostatic latent image formation instruction, and averages every image reading mode except for the interval time longer than the predetermined time from the interval time. An image forming apparatus that calculates an interval time and drives the drive motor at a lower speed than the normal operation state and waits for a predetermined multiple of the average interval time after the end of the normal operation state.

  FIG. 1 is a side view showing the internal structure of a tandem type full-color printer as an image forming apparatus according to an embodiment of the present invention. Although the control during standby for continuous printing is different from the conventional one, the basic configuration is the same as the conventional one. This image forming apparatus employs an AIO cartridge as a process cartridge. The image forming unit of the full-color printer 100, which is an image forming apparatus, includes four AIO cartridges (AIO cartridge (K) 1, AIO cartridge (C) 2, AIO cartridge (M) 3, AIO cartridge (with built-in image forming unit)). Y) 4), an intermediate transfer belt 5 positioned below these AIO cartridges, and a secondary transfer roller 6 as a secondary transfer member. Y, M, C, and K in parentheses mean yellow, magenta, cyan, and black colors, respectively.

  The four AIO cartridges form toner images of different colors. These four AIO cartridges have the same structure. The AIO cartridge includes cylindrical photoconductors 1a, 2a, 3a, 4a that are rotatable image carriers, and charging rollers 1b, 2b, 3b arranged around these photoconductors in the order of the electrophotographic process. 4b, a developing device (not shown), and cleaning devices 1c, 2c, 3c, and 4c. The four photoconductors are arranged in parallel with each other at equal intervals. The photoreceptors 1a, 2a, 3a, 4a are rotationally driven at a peripheral speed of 120 mm / sec by a motor (not shown) during an image forming operation. The charging rollers 1b, 2b, 3b, and 4b are in pressure contact with the photoreceptors 1a, 2a, 3a, and 4a, respectively, and are driven to rotate with respect to the photoreceptors 1a, 2a, 3a, and 4a. The charging rollers 1b, 2b, 3b, and 4b uniformly charge the surfaces of the photoreceptors 1a, 2a, 3a, and 4a by applying an AC and DC bias from a high voltage power source (not shown).

  The developing device performs one-component development. These developing devices visualize the electrostatic latent images formed on the surfaces of the photoreceptors 1a, 2a, 3a, and 4a as toner images by a predetermined developing bias supplied from a high voltage power source (not shown). The cleaning devices 1c, 2c, 3c, and 4c in the AIO cartridge clean the transfer residual toner on the surfaces of the photoreceptors 1a, 2a, 3a, and 4a. The intermediate transfer belt 5 is stretched around a drive roller 5a and a support roller 5b. The intermediate transfer belt 5 is rotationally driven by a motor (not shown).

  Inside the intermediate transfer belt 5, four primary transfer bias rollers 5c, which are primary transfer members, are provided. The four primary transfer bias rollers 5c are disposed opposite to the transfer positions of the photoreceptors Y, M, C, and K via the intermediate transfer belt 5, respectively. The primary transfer bias roller 5 c is applied with a primary transfer bias by a primary transfer bias application unit that constitutes a transfer bias application unit (not shown), and transfers the toner image on the surface of the photoreceptor onto the surface of the intermediate transfer belt 5. The primary transfer bias application unit is a high voltage power source. A cleaning device 7 for cleaning the intermediate transfer belt 5 is provided in the vicinity of the support roller 5b.

  The secondary transfer roller 6 is provided at a position facing the support roller 5b with the intermediate transfer belt 5 interposed therebetween. The secondary transfer roller 6 is applied with a secondary transfer bias by a secondary transfer bias applying unit constituting a transfer bias applying unit (not shown), and the intermediate transfer belt 5 is applied to a sheet 8 that is a recording material sandwiched between the intermediate transfer belt 5. The upper toner image is secondarily transferred. The secondary transfer bias application unit is a high voltage power source.

  The optical writing unit 9 is arranged on the upper side of the four AIO cartridges, and irradiates the surface of each photoconductor with laser light corresponding to the image data for each color of YMCK. An electrostatic latent image is formed. As the optical writing unit 9, a laser scanning type using a laser light source, a polygon mirror or the like is shown, but a type combining an LED array and an imaging means may be used.

  The paper 8 is stored and held in the paper feed cassette 10, and the paper 8 is separated and fed one by one by the paper feed roller 11. The sheets 8 separated and fed one by one are conveyed to the secondary transfer position by the registration roller 12. The sub-scanning length of the paper 8 is measured by the registration sensor 13. The fixing device 14 fixes the toner image on the paper 8 by applying heat and pressure to the paper 8 on which the toner image is transferred. The secondary transfer roller 6 is in contact with the intermediate transfer belt 5, but when a contact / separation mechanism is provided, unnecessary toner on the intermediate transfer belt 5 is prevented from being transferred to the secondary transfer roller 6. The paper is separated when a paper jam occurs.

  FIG. 2 is a diagram illustrating a schematic configuration of the composite apparatus. The basic configuration is the same as the conventional one. In FIG. 2, an image forming apparatus 100 is a multifunction machine having functions such as a copying machine using an electrophotographic process, a printer, and a facsimile. The printer unit 110 is means for executing printing. The paper feeding unit 120 is a unit that supplies printing paper. The operation unit 111 is a means for displaying various types of information and inputting various types of information through user operations. The scanner 112 is an image reading device equipped with an ADF (automatic document feeder).

  FIG. 3 is a functional block diagram of the image forming apparatus. The basic configuration is the same as the conventional one. In FIG. 3, an image forming apparatus 100 is a multifunction machine having functions such as a copying machine using an electrophotographic process, a printer, and a facsimile. The CPU 101 is a central control device that controls the entire image forming apparatus 100. The writing control unit 102 is means for controlling the plotter 102a that performs the writing operation on the recording paper. A plotter 102a for writing on the recording paper is connected to the writing control unit 102. The image processing unit 103 is means for performing predetermined image processing on the image data read from the scanner 103a. The image processing unit 103 is connected to a scanner 103a that reads an image.

  The I / O control unit 104 is a unit that controls the sensor 104a and the driver 104b, selects a sheet feeding unit (not shown), and the like. The I / O control unit 104 is connected to a sensor 104a as various electrical components and a driver 104b as a driving means. The modem 105 is means for connecting to the public network via the NCU 105a. Connected to the modem 105 is an NCU (Network Control Unit) 105a that transmits a dial signal to call a communication partner when connected to the public network. The interface unit 106 is means for performing communication with the PC 200. The interface unit 106 is connected to a PC (personal computer) 200 which is an external device. The operation unit 107 is a unit for inputting various information to the apparatus and a display unit for displaying various information by a user operation. The storage unit 108 is a memory that stores image data and the like.

  FIG. 4 is a timing chart of image formation preparation (initialization) at the time of color printing in the image forming apparatus. FIG. 5 is a flowchart of time measurement in the image forming apparatus. FIG. 6 is a timing chart of the black motor of the image forming apparatus.

  The function and operation of the image forming apparatus in the embodiment of the present invention configured as described above will be described. First, an overview of the functions of the image forming apparatus regarding the standby operation in continuous printing will be described. The image reading unit reads the image data of the document. The image reading unit includes a document conveying unit that conveys originals one by one from a bundle of documents to an image reading position and reads image data, and a FAX receiving unit that receives image data via an external communication line. The image data read by the image reading means is converted into image data for printing by the image processing means. The writing means projects light onto the photoconductor based on the printing image data to form an electrostatic latent image. The developing unit converts the electrostatic latent image into a visible image with toner. The visible image of the toner is transferred to the printing paper directly or via an intermediate transfer member by the transfer means. In the image forming apparatus, an image is formed by an electrophotographic process in this way.

  The interval time measuring means measures an interval time from the end of electrostatic latent image formation to the next electrostatic latent image formation instruction. An average calculation unit calculates an average interval time of the interval times. An interval time longer than the predetermined time is determined not to be continuous printing, and is excluded from the calculation of the average interval time. In order not to make the extension time longer than necessary, the average interval time is calculated for each type and mode of image reading. After the end of the normal operation state, the extension means sets the standby state for a predetermined multiple of the average interval time. The extension means controls the drive motor to be driven at a lower speed than the normal operation state.

  Next, an image forming operation of the full-color printer 100 will be described with reference to FIG. The image forming operation is performed in a state where a photosensitive member having a color corresponding to the image forming mode is in contact with the intermediate transfer belt 5. Laser light corresponding to image data is emitted from a semiconductor laser (not shown) of the optical writing unit 9, and the surface of each photoconductor is electrostatically charged by irradiating the surface of each photoconductor. A latent image is formed. Toner supplied from each developing device adheres to the electrostatic latent image, and is visualized as a toner image. The toner images are sequentially primary-transferred sequentially by the transfer action of each primary transfer bias roller 5c to which a primary transfer bias is applied to the surface of the intermediate transfer belt 5 that moves in synchronization with the photosensitive member. As described above, the toner images of different colors formed on the surfaces of the respective photoreceptors are sequentially superimposed on the intermediate transfer belt 5 and primarily transferred, whereby a color toner image is formed on the intermediate transfer belt 5. The In the single color mode, there is one color and there is no superposition of toner images.

  The toner image on the intermediate transfer belt 5 is secondarily transferred to the paper 8 fed from the paper feed cassette 10 and sent to the transfer position between the secondary transfer roller 6 and the intermediate transfer belt 5. This secondary transfer is executed by the transfer action of the secondary transfer roller 6 to which a secondary transfer bias is applied. The sheet 8 on which the color toner image has been transferred is fixed by the fixing device 14 and discharged from a discharge port 15 provided in the main body of the full-color printer 100 after the fixing processing.

  Next, the operation of the composite apparatus will be described with reference to FIG. When scanning using the ADF, set the document bundle in the ADF and instruct the start of scanning. When scanning is started, the document is transported one by one from the document bundle to the reading position, and scanning is automatically performed until the final document. Repeat. Documents that cannot be loaded into the ADF are read from the platen. In this case, the user exchanges the originals one by one and issues a reading start instruction.

  The copying operation is realized by converting the image data read from the scanner into printer output data and outputting it to the printer. The paper feeding unit 120 is divided into a first paper feeding unit 121, a second paper feeding unit 122, and a third paper feeding unit 123. The image forming apparatus 100 can be connected to an external PC 200 via an interface unit (not shown). In addition, connection to a public network is possible via a modem (not shown). Here, at the time of FAX transmission, the image data read from the scanner is converted into FAX image data, and then transmitted to the external line via the modem / NCU. Conversely, when receiving a fax, the fax image data is converted into image data for printer printing and output to a printer.

  Next, the control operation of the image forming apparatus will be described with reference to FIG. The user inputs various information from the operation unit 107 on which various information is displayed. The image data read from the scanner 103a is accumulated in the storage unit 108 and processed by the image processing unit 103. The writing control unit 102 controls the plotter 102a to write on the recording paper. The CPU 101 controls the entire image forming apparatus 100, and the I / O control unit 104 controls the sensor 104a and the driver 104b. The interface unit 106 communicates with the PC 200, and the modem 105 connects to the public network via the NCU 105a.

  Next, image formation preparation (initialization) timing during color printing will be described with reference to FIG. K AIO and the intermediate transfer belt are driven by the same black motor. Y, M, C color AIO is driven by a color motor. The intermediate transfer belt is brought into and out of contact with the Y, M, and C color AIOs by a contact and separation motor. During standby, the intermediate transfer belt is separated from the Y, M, and C color AIOs. A motor that drives the paper transport and the secondary transfer bias roller is a main motor.

The operation steps are as follows.
[1] A color print request comes from the controller.
[2] Start the main motor. It takes 500ms for the rotation to stabilize. Start the polygon motor. It takes up to 4 seconds for the rotation to stabilize.
[3] Wait for the rotation of the main motor to stabilize, and then apply a black developing bias. Startup time is 50ms.
[4] When the black development bias rises, start the black motor. It takes 500ms for the rotation to stabilize.
[5] Wait for the rotation of the black motor to stabilize, and then apply a color developing bias. Startup time is 50ms. A secondary transfer bias is applied. Startup time is 50ms.
[6] When the color development bias rises, start the color motor. It takes 500ms for the rotation to stabilize.
[7] Wait until the rotation of the color motor is stabilized and press the intermediate transfer belt. It takes 2 seconds to complete.
[8] Wait for the rotation of the polygon motor to stabilize, and then apply a charging bias. Startup time is 50ms.
[9] Wait until the charged potential on the photoreceptor is stabilized. Wait for two rotations of the photoreceptor.

  After the above startup process, writing becomes possible. In this way, since it starts while taking the timing of bias application with each motor, it takes time before printing is possible (exposure to the photoconductor), but at the same time when the motor drive speed is changed after startup. To do. The stabilization time is also shortened. Although the time required for stabilization varies depending on each motor, the maximum is 1 second for the polygon motor and 100 ms for the other motors. The operation of this part is the same as the conventional one.

  Next, the procedure of time measurement will be described with reference to FIG. At the end of writing, it is determined from which function the print request is issued, and for each function, time measurement is performed for each mode that affects the print image preparation time for each function. In this example, the reading mode from the scanner is the pressure plate mode or the ADF mode. There are several modes that affect the print image preparation time depending on the model, such as single-side mode / double-side mode, resolution, and image size. The time over is checked during time measurement, and the average time is not updated when the time over occurs. This is because when the time is over, it is determined that the printing is not continuous printing. The measurement is terminated when the next print request is received. At this time, if the drive extension operation is in progress, the drive speed is changed to the normal operation speed.

  In step 1, wait until the black writing is completed. In step 2, it is checked whether the print request is received from the printer. If it is a print request from the printer, the extension time is set to 0 in step 3 and the process ends. If it is not a print request from the printer, it is checked in step 4 if it is a print request from the FAX function unit. If it is a print request from the FAX function unit, the time is measured in step 5. In step 6, it is checked whether the time is over. If time is over, the process ends. If the time is not over, it is checked in step 7 whether there is a next print request. If there is no next print request, the time measurement is continued. If there is a next print request, it is checked in step 8 if it is a print request in the same mode from the same function unit. If so, in step 9, the average time is updated and the extended time is calculated. In step 10, set the extension time and finish.

  If it is not a print request from the FAX function unit, it is checked in step 11 if it is a print request from the scanner function unit. Otherwise it ends. If it is a print request from the scanner function unit, it is checked in step 12 whether it is read from the second scanner. If not, it is checked in step 13 whether or not it is read from the first scanner. Otherwise it ends. If it is read from the first scanner, the time is measured in step 14. In step 15, it is checked whether the time is over. If time is over, the process ends. If the time is not over, it is checked in step 16 whether there is a next print request. If there is no next print request, the time measurement is continued. If there is a next print request, it is checked in step 17 whether it is a print request in the same mode from the same function unit. If so, in step 18, the average time is updated to calculate the extension time. In step 19, the extension time is set and the process ends.

  If it is read from the second scanner, the time is measured in step 20. In step 21, it is checked whether the time is over. If time is over, the process ends. If the time is not over, it is checked in step 22 whether there is a next print request. If there is no next print request, the time measurement is continued. If there is a next print request, it is checked in step 23 if it is a print request in the same mode from the same function unit. If so, in step 24, the average time is updated to calculate the extended time. In step 25, the extension time is set and the process ends.

  If the print request source function is the same as the time-measured function and the mode is the same, the average time is updated and the drive extension time is set. In the case of a request from the printer function, the continuous printing cannot normally be delayed, so the drive extension time is set to zero. Here, when the average time Ta0 of the first reading device is 8.5 seconds, the average time Ta1 of the second reading device is 5.2 seconds, and the average time Ta2 of FAX is 3.2 seconds, the predetermined magnification is uniformly 1.8 times. The extension time is Tb0 = 15.3 seconds, Tb1 = 9.4 seconds, and Tb2 = 5.8 seconds. The prescribed time Tc0 = Tc1 = Tc2 = 20 seconds, but different prescribed times may be provided. Further, in an apparatus having a plurality of drive sources, the individual drive extension time may be calculated so that each timing is matched from the calculation time.

  Next, the timing of the black motor will be described with reference to FIG. In the stop state, the black motor is stopped. When a print request is received from the controller, the black motor starts to rotate. It takes 500ms for the rotation to stabilize. After that, it waits about 5 seconds until the initialization is completed, and writing is performed. When writing is finished, the device waits for a certain period of time in the driving state. When the next print request is received during the driving state, writing is started. Up to this point, the operation is the same as the conventional operation. If the image preparation time is long and the next print request does not come even after a certain period of time, the rotation speed of the black motor is reduced and the apparatus enters a standby state. The standby state is continued for the extended drive time. If the next print request does not come by the end of the drive extension time, the black motor is stopped and brought to a stop state.

  When the next print request is received during the standby state, the rotation of the black motor is returned to the operation state, and writing is performed after a short initialization time. When writing is finished, the device waits for a certain period of time in the driving state. After a certain period of time, the rotation speed of the black motor is reduced and a standby state is entered. The standby state is continued for the extended drive time. When the drive extension time is over, stop the black motor and put it in a stopped state. In response to a print request from the controller, the write timing is the same as before when the first print is started. For the second and subsequent prints, the standby time is set for an extended time, so the initialization time is shortened and writing is accelerated. Image printing efficiency can also be improved in printing for devices and modes with different image preparation times for each sheet.

  As described above, in the embodiment of the present invention, the image forming apparatus measures the interval time from the end of electrostatic latent image formation to the next electrostatic latent image formation instruction, and the interval time is longer than the predetermined time from the interval time. Except for, the average interval time is calculated for each image reading mode, the drive time is extended by a predetermined multiple of the average interval time, and it is configured to wait at a lower speed than the normal speed. Printing efficiency can be improved.

  The image forming apparatus of the present invention is optimal as a high-speed and long-life composite apparatus that can realize the functions of copying, printers, scanners, and facsimiles with a small image memory.

1 is a side view showing an internal structure of an image forming apparatus in an embodiment of the present invention. 1 is a diagram illustrating a schematic configuration of an image forming apparatus according to an embodiment of the present invention. 1 is a functional block diagram of an image forming apparatus in an embodiment of the present invention. FIG. 5 is a timing diagram of initialization at the time of color printing in the image forming apparatus according to the exemplary embodiment of the present invention. It is a flowchart of time measurement in the image forming apparatus in the embodiment of the present invention. FIG. 4 is a timing diagram of a black motor in the image forming apparatus according to the embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... AIO cartridge (K), 1a ... Photoconductor, 1b ... Charging roller, 1c ... Cleaning device, 2 ... AIO cartridge (C), 2a ... Photoconductor, 2b ..Charging roller, 2c ... cleaning device, 3 ... AIO cartridge (M), 3a ... photoconductor, 3b ... charging roller, 3c ... cleaning device, 4 ... AIO cartridge ( Y), 4a ... photoconductor, 4b ... charge roller, 4c ... cleaning device, 5 ... intermediate transfer belt, 5a ... drive roller, 5b ... support roller, 5c ... Primary transfer bias roller, 6 ... secondary transfer roller, 7 ... cleaning device, 8 ... paper, 9 ... optical writing unit, 10 ... feed cassette, 11 ... feed Paper roller, 12 ... Registration roller, 13 ... Registration sensor, 14 ... Fixing device, 15 ... Discharge port, 100 Image forming apparatus 101 ... CPU 102 ... Write control unit 102a ... Plotter 103 ... Image processing unit 103a ... Scanner 104 ... Control unit 104a Sensor 104b Driver 105 Modem 106 Interface unit 107 Operation unit 108 Storage unit 110 Printer 111 111 Operation unit 112... Scanner, 120... Paper feed unit, 121... Paper feed unit, 122.

Claims (7)

  An image reading unit that reads image data of an original, an image processing unit that converts image data read by the image reading unit into image data for printing, and a static light by projecting light on the photoconductor based on the image data for printing. A writing unit that forms an electrostatic latent image, a developing unit that converts the electrostatic latent image into a visible image with toner, and a transfer unit that transfers the visible image of the toner directly or via an intermediate transfer member, In an image forming apparatus that forms an image by an electrophotographic process, an interval time measuring unit that measures an interval time from the end of electrostatic latent image formation to the next electrostatic latent image formation instruction, and an average interval time of the interval times are calculated. An image forming apparatus comprising: an average calculating unit configured to perform a standby state for a predetermined time that is a predetermined multiple of an average interval time after completion of the normal operation state.   2. The image forming apparatus according to claim 1, wherein the extension means includes means for controlling the drive motor to drive at a lower speed than in a normal operation state.   The image forming apparatus according to claim 1, wherein the average calculating unit includes a unit that excludes an interval time longer than a predetermined time from the calculation of the average interval time.   2. The image forming apparatus according to claim 1, wherein the image reading unit includes a document conveying unit that conveys one document at a time from the document bundle to an image reading position and reads image data.   2. The fax receiving means for receiving image data via an external communication line, wherein the image processing means comprises means for converting image data from the fax receiving means into image data for printing. The image forming apparatus described.   The image forming apparatus according to claim 1, wherein the average calculating unit includes a unit that calculates an average interval time for each type and mode of image reading.   In an image formation control method for forming an image by an electrophotographic process, an interval time from the end of electrostatic latent image formation to the next electrostatic latent image formation instruction is measured, and an interval time longer than a predetermined time is excluded from the interval time. The average interval time is calculated for each type and mode of image reading, and after completion of the normal operation state, the drive motor is set in a standby state in which the drive motor is driven at a lower speed than the normal operation state for a predetermined time. An image formation control method.

Images