JP2010113237A - Image forming apparatus and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an image forming apparatus and a program capable of suppressing power consumption for heating while securing required heating time when heating a recording medium. <P>SOLUTION: When a predetermined state in which performance of image forming operation on paper is predicted is detected, a CPU 40 controls a power supply 58 to delay start of power supply to a heating roller according as the power suppliable to a heating roller provided in an image forming engine part 15 by the power supply 58 gets larger. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image forming apparatus and a program.

Patent Document 1 includes a fixing device that performs fixing processing, a control panel for setting operation details, and a timer that measures time, and the fixing device is in a standby state in which a first fixing temperature is set. When the control panel does not operate until the time measured by the timer reaches a predetermined time, a second fixing temperature lower than the first fixing temperature is set, and then A technique for setting a third fixing temperature higher than the first fixing temperature when an operation is performed on the control panel is disclosed.
JP 2005-37488 A

  SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming apparatus and a program capable of suppressing power consumption for heating while securing a heating time required for heating a recording medium.

  In order to achieve the above object, an image forming apparatus according to claim 1, a heating unit that heats a recording medium on which an image is formed, a supply unit that supplies heating power to the heating unit, and the recording When a predetermined state in which execution of an image forming operation on the medium is predicted is detected, the start of power supply to the heating unit is delayed as the power that can be supplied to the heating unit by the supply unit increases. And a control means for controlling the supply means.

  According to a second aspect of the present invention, in the first aspect of the present invention, when the control unit detects the predetermined state, the power that can be supplied to the heating unit by the supply unit is provided. When it is equal to or higher than the predetermined power, the supply means is controlled so as to delay the start of power supply to the heating means as compared with the case where the power is lower than the predetermined power.

  The invention according to claim 3 is the invention according to claim 1 or 2, wherein the control means supplies the power that can be supplied by the supply means. Judgment is based on the temperature rise rate of the heating means or the configuration state of other drive parts that are driven by power supplied from the supply means.

  The invention according to claim 4 is the invention according to any one of claims 1 to 3, wherein the temperature of the heating means when power is supplied to the heating means by the supply means. An acquisition means for acquiring an increase rate; and a measurement means for measuring the temperature of the heating means or a temperature in the vicinity of the heating means, and when the control means detects the predetermined state, Based on the temperature increase rate acquired by the acquisition unit and the temperature measured by the measurement unit, it is predicted that the image formation will actually start after the supply of power from the supply unit to the heating unit is started. A period from the present time to the start of power supply from the supply means to the heating means so that the temperature of the heating means reaches a target temperature for heating the recording medium in the period until Deriving a certain feed start time, and performs the control by controlling the supply means so as to start the power supply after the lapse of the derived power supply start period.

According to a fifth aspect of the present invention, in the invention according to the fourth aspect, the control means sets the temperature increase rate to α, sets the temperature measured by the measuring means to β, and sets the target temperature to γ. The power supply start period t is calculated by the following arithmetic expression, where t _x is a period from when the predetermined state is detected to when the actual image formation is predicted to start. It is.

また、請求項６に記載の発明は、請求項４または請求項５に記載の発明において、前記記録媒体の種類、及び画像形成モードの種類の少なくとも一方を取得する種類取得手段をさらに備え、前記制御手段が、前記目標温度を、前記種類取得手段によって取得された種類に基づいて決定するものである。

The invention described in claim 6 is the invention described in claim 4 or 5, further comprising type acquisition means for acquiring at least one of the type of the recording medium and the type of image forming mode, The control means determines the target temperature based on the type acquired by the type acquisition means.

  The invention according to claim 7 further comprises a detection means for detecting the magnitude of electric power supplied to the heating means by the supply means in the invention according to claim 1 or claim 2, wherein The control means performs the control based on the magnitude of the electric power detected by the detection means.

  The invention according to claim 8 is the invention according to any one of claims 1 to 7, wherein the control means detects the predetermined state and the recording. The control is performed while waiting for an image forming operation on the medium.

  The invention according to claim 9 is the invention according to any one of claims 1 to 8, wherein the predetermined state is performed as a stage before an instruction to execute image formation by a user. In this state, at least one of a state where a predetermined operation is performed and a state where image information indicating an image to be formed from an external device is received is received.

  The invention according to claim 10 is the invention according to claim 9, wherein the predetermined operation reads the image recorded on the original and forms the image on the recording medium. An operation for placing a document at a predetermined reading position, an operation for opening and closing the cover when a cover for covering the region where the document is placed is placed with the document placed, and a plurality of documents automatically This is at least one of the operations for placing the original on the automatic original feeder when the automatic original feeder is readable.

  Furthermore, an invention according to claim 11 is the invention according to any one of claims 1 to 10, wherein an image holding body on which an electrostatic latent image is formed and held, and the image holding body A developing unit that develops the formed electrostatic latent image into a visible image with a developer; and a transfer unit that transfers the visible image on the image carrier to the recording medium. The heating unit includes the recording unit. The fixing means fixes the visible image transferred to the recording medium by heating the medium.

  On the other hand, in order to achieve the above object, a program according to claim 12 includes a heating unit that heats a recording medium on which an image is formed, and a supply unit that supplies heating power to the heating unit. A program executed in the image forming apparatus, wherein the computer can be supplied to the heating unit by the supply unit when a predetermined state in which the execution of the image forming operation on the recording medium is predicted is detected. The purpose of this is to function as control means for controlling the supply means so that the start of power supply to the heating means is delayed as the power increases.

  In order to achieve the above object, a program according to a thirteenth aspect causes a computer to function as a control unit in the image forming apparatus according to any one of the first to eleventh aspects. is there.

  According to the invention of Claim 1, Claim 12, and Claim 13, the effect that the power consumption for a heating can be suppressed, ensuring the heating time required is acquired.

  Further, according to the invention described in claim 2, it is possible to more easily suppress the power consumption for heating while securing the required heating time as compared with the case where the present invention is not applied. The effect of being able to be obtained is obtained.

  In addition, according to the invention described in claim 3, the present invention can be realized at a lower cost compared to a case where a detection unit for detecting the magnitude of electric power that can be supplied to the heating unit is provided. can get.

  Further, according to the invention described in claim 4, it is possible to suppress the power consumption for heating while ensuring the required heating time more reliably than in the case where the present invention is not applied. The effect of being able to be obtained is obtained.

  Further, according to the invention described in claim 5, it is possible to more easily suppress the power consumption for heating while securing the required heating time as compared with the case where the present invention is not applied. The effect of being able to be obtained is obtained.

  Further, according to the invention described in claim 6, compared with the case where the present invention is not applied, the power consumption for heating is suppressed while ensuring the required heating time with higher accuracy. The effect of being able to be obtained.

  In addition, according to the invention described in claim 7, the required heating time is more accurately compared with the case where the magnitude of the electric power that can be supplied to the heating means is indirectly determined by other physical quantities. The effect that the power consumption for heating can be suppressed is obtained while ensuring the above.

  In addition, according to the invention described in claim 8, compared with the case where the present invention is not applied, the power consumption for heating can be suppressed more effectively while securing the required heating time. The effect of being able to be obtained.

  Further, according to the invention described in claim 9, when the applied state is detected, it is possible to suppress the power consumption for heating while securing the required heating time. The effect is obtained.

  In addition, according to the invention of claim 10, the power consumption for heating can be suppressed while ensuring the required heating time, specially when the applied operation is detected. The effect is obtained.

  According to the eleventh aspect of the present invention, the power consumption for heating is suppressed while securing the heating time required for fixing the visible image in the fixing means in the electrophotographic image forming apparatus. The effect that it can do is acquired.

  The best mode for carrying out the present invention will be described below in detail with reference to the drawings.

[First Embodiment]
FIG. 1 shows a front view of an image forming apparatus 10 according to the present embodiment.

  As shown in FIG. 1, the image forming apparatus 10 reads an image from a document placed at a predetermined image reading position, acquires image data indicating the image, and the scanner 11 acquires the image data. An apparatus main body 12 that performs image forming processing using various image data such as image data and image data acquired from an external apparatus, and a paper feed that supplies paper 31 (see also FIG. 2) as a recording medium to the apparatus main body 12. An image is formed by the device 13, a touch panel display (hereinafter referred to as “display”) 14 that displays various information such as operation menus and messages, and is integrally provided with a transparent touch panel on the display surface. And a discharge tray 39 for holding the paper 31 (see also FIG. 2) discharged from the apparatus main body 12.

  Note that in the image forming apparatus 10 according to the present embodiment, a pressure-sensitive touch panel is used as the touch panel, and image formation is performed when the user touches the display surface of the display 14 with a fingertip (touch operation). Various operations can be instructed to the apparatus 10.

  The scanner 11 according to the present embodiment also has a function of detecting the size of the original document in addition to a function of reading an image of the placed original document.

  The sheet feeding device 13 according to the present embodiment includes four sheet feeding trays 30A, 30B, 30C, and 30D. The paper feed trays 30A to 30D can change the size of the paper 31 to be stored by adjusting the position of an internal partition member or the like, and each of the paper feed trays 30A to 30D has a different size. The sheets 31 are stored in a stacked state.

  The sheet feeding device 13 conveys the sheets 31 stored from any one of the sheet feeding trays 30 </ b> A to 30 </ b> D one by one and supplies them to the apparatus main body 12. In the following description, when the paper feed trays 30A to 30D are not particularly distinguished, the alphabet at the end of the reference numerals is omitted.

  Next, the internal configuration of the apparatus main body 12 will be described in detail with reference to FIG.

  As shown in the figure, the apparatus main body 12 according to the present embodiment includes an image forming engine unit 15 that performs an image forming process on a sheet 31 by an electrophotographic method.

  The image forming engine unit 15 according to the present embodiment is of a full color type and includes four image forming units 20Y, 20M, 20C, and 20K. These image forming units 20Y, 20M, 20C, and 20K are arranged at predetermined intervals along the longitudinal direction of the intermediate transfer belt 18. The intermediate transfer belt 18 is stretched around a plurality of winding rollers 19 and has an endless belt shape that is conveyed at a predetermined speed in the direction of arrow E in FIG.

  The image forming unit 20Y corresponds to yellow (Y), the image forming unit 20M corresponds to magenta (M), the image forming unit 20C corresponds to cyan (C), and the image forming unit 20K corresponds to black (K). An image of each corresponding color is formed. In FIG. 2, an alphabet (Y / M / C / K) indicating a color corresponding to the end of the code is given, but in the following, this alphabet at the end of the code is omitted unless the color is particularly distinguished. I will explain.

  The image forming unit 20 is provided with a cylindrical photosensitive drum 22 that is rotationally driven at a predetermined rotational speed in the direction of arrow F in FIG. Further, a charger 24 for uniformly charging the surface of the photosensitive drum 22 is disposed around each photosensitive drum 22. Charging of the photosensitive drum 22 by the charger 24 is the first stage of a series of image forming processes. Further, a light beam based on a desired image is irradiated in the axial direction of the photosensitive drum 22 uniformly charged by the charger 24 on the downstream side of the charger 24 along the rotation direction of each photosensitive drum 22. A ROS (Raster Output Scanner) 26 for forming an electrostatic latent image is disposed on the photosensitive drum 22.

  Further, around each photosensitive drum 22, a color (yellow / yellow) formed on the photosensitive drum 22 on the downstream side of the ROS 26 along the rotation direction of the photosensitive drum 22. A developing device 28 is provided for developing with toner of any one of magenta / cyan / black) to form a toner image. A contact point with the intermediate transfer belt 18 is located downstream of the developing device 28, and a first transfer device 29 is disposed so as to sandwich the intermediate transfer belt 18 with the photosensitive drum 22. Yes. The first transfer unit 29 applies a predetermined voltage to transfer the toner image on the photosensitive drum 22 to the intermediate transfer belt 18.

  The toner images of different colors formed on the respective photosensitive drums 22 are respectively transferred to the intermediate transfer belt 18 so as to overlap (in the same area) on the belt surface of the intermediate transfer belt 18. As a result, a full-color toner image is formed on the intermediate transfer belt 18. In this embodiment, the toner image in which the four color toner images are transferred in a superimposed manner is referred to as a “final toner image”.

  A second transfer unit 34 including a pair of rollers 34A and 34B is disposed on the downstream side in the transport direction (in the direction of arrow E in FIG. 2) from the toner image transfer position from the photosensitive drum 22 of the intermediate transfer belt 18. Has been. Between the rollers 34 </ b> A and 34 </ b> B in the second transfer unit 34, the paper 31 taken out from the paper feed tray 30 by the pickup roll 32 and conveyed by the plurality of conveyance rollers 33 is sandwiched. The final toner image is transferred from the intermediate transfer belt 18 to the paper 31 by this nipping and conveying. Further, a photo sensor 35 is disposed upstream of the second transfer unit 34 in the transport path along which the paper 31 is transported, and the photo sensor 35 detects that the paper 31 has passed.

  The paper 31 to which the final toner image has been transferred is conveyed to a nip portion between the rollers 36A and 36B of the fixing device 36 composed of a pressure roller 36A and a heating roller 36B that are arranged to face each other, and is subjected to heat fixing. As a result, the final toner image is fixed on the paper 31 and a desired image (color image) is formed on the paper 31. The sheet 31 on which the image is formed is discharged to a discharge tray 39 by a pair of discharge rollers 38 disposed on the downstream side of the fixing device 36 in the sheet conveyance direction.

  Next, with reference to FIG. 3, the main configuration of the electrical system of the image forming apparatus 10 will be described.

  The image forming apparatus 10 includes a CPU (central processing unit) 40 that controls the operation of the entire apparatus, a RAM (Random Access Memory) 41 that is used as a work area when various programs are executed, and a power supply control processing program described later. A ROM (Read Only Memory) 42 in which various programs and various parameters are stored in advance, a flash memory 43 in which various information such as target temperature information to be described later is stored, and control for displaying various information on the display 14 are performed. A display driver 44 and an operation input detection unit 46 that detects a touch operation on the display 14 are provided.

  In addition, the image forming apparatus 10 includes a scanner driver 50 that controls an optical image reading operation by the scanner 11, an image forming engine control unit 54 that controls each part of the image forming engine unit 15, and the paper feeding described above. A sheet feeding device control unit 56 that controls the conveyance operation of the sheet 31 by the apparatus 13 and a power source 58 that supplies electric power of a corresponding voltage to each unit driven by electric power are provided.

  The scanner 11 according to the present embodiment includes a document detection sensor 11A that detects that a document is placed at the image reading position. As the document detection sensor 11A, various conventionally known sensors such as a sensor that optically detects a placed document using a photo sensor or the like, or a sensor that mechanically detects a document using a mechanical switch or the like. Is applicable.

  In addition, the image forming engine unit 15 according to the present exemplary embodiment is provided with a temperature sensor 15A for detecting the temperature of the heating roller 36B in the fixing device 36. In the image forming apparatus 10 according to the present embodiment, the temperature sensor 15A is embedded in the peripheral surface of the heating roller 36B. However, the present invention is not limited thereto, and the sensing unit is in contact with the outer surface of the heating roller 36B. Alternatively, the sensing unit may be fixedly provided on the apparatus housing or the like with the sensing unit positioned in the vicinity of the heating roller 36B. Moreover, as this temperature sensor 15A, various sensors which detect temperature, such as a thermistor, are applicable.

  The CPU 40, RAM 41, ROM 42, flash memory 43, display driver 44, operation input detection unit 46, scanner driver 50, image forming engine control unit 54, paper feed device control unit 56, and power source 58 are mutually connected via the system bus BUS. It is connected. Therefore, the CPU 40 accesses the RAM 41, the ROM 42, and the flash memory 43, displays various information on the display 14 via the display driver 44, controls the operation of the scanner 11 via the scanner driver 50, and the image forming engine. Control of the operation of each part of the image forming engine unit 15 via the control unit 54, and control of the conveying operation of the paper 31 stored in each paper feed tray 30 of the paper feed device 13 via the paper feed device control unit 56 The power supply 58 can control the power supply to each unit. Further, the CPU 40 displays an operation instruction by a user's touch operation on the display 14, a document size read by the scanner 11 via the scanner driver 50, a document detection result by the document detection sensor 11 </ b> A, and an image forming engine control unit 54. And the temperature of the heating roller 36B detected by the temperature sensor 15A.

  In the image forming apparatus 10 according to the present embodiment, the types of paper used for image formation via the display 14 (in this embodiment, three types of “plain paper”, “thick paper”, and “OHP sheet”). The type of image forming mode (in this embodiment, three types of “monochrome mode”, “two-color mode”, and “full-color mode”) can be designated.

  By the way, in order to reduce power consumption without causing deterioration in operability, productivity, and image quality, as described above, in the technique disclosed in Patent Document 1, the fixing device has a first fixing temperature. In the set standby state, if there is no operation from the user until the measured time reaches a predetermined time, the second fixing temperature lower than the first fixing temperature is set, and then the user When the operation is performed, the third fixing temperature higher than the first fixing temperature is set.

  However, in this case, when sufficient power can be secured from the power source to the heating roller of the fixing device, as shown in FIG. 4A as an example, a short time is required until image formation is actually started. Therefore, if a power supply to the heating roller is started earlier than necessary, the power consumption is wasted.

  On the other hand, when sufficient power that can be supplied from the power source to the heating roller of the fixing device cannot be secured, as shown in FIG. 4B as an example, the timing of starting the power supply to the heating roller is advanced. In some cases, a sufficient amount of heat cannot be obtained until image formation is started. In this case, it is difficult to ensure the required heating time.

  In view of this, in the image forming apparatus 10 according to the present embodiment, the function of optimizing the start timing of power supply to the heating roller 36B of the fixing device 36 based on the magnitude of the voltage that can be supplied to the heating roller 36B by the power source 58. (Hereinafter referred to as “power supply start optimization function”).

  FIG. 5 is a graph showing an example of the relationship between the elapsed time from the start of power feeding and the temperature of the heating roller 36B at a plurality of different supplyable voltages from the power source 58 to the heating roller 36B.

  As shown in the figure, the relationship between the elapsed time and the temperature is proportional, and the gradient is proportional to the voltage that can be supplied from the power source 58.

  Therefore, in the power supply start optimization function according to the present embodiment, the power supply 58 supplies the heating roller 36 </ b> B of the fixing device 36 when a predetermined state in which the execution of the image forming operation on the paper 31 is predicted is detected. The power source 58 is controlled so that the start of power supply to the heating roller 36B is delayed as the available power increases.

  In particular, in the power supply start optimization function according to the present embodiment, the magnitude of the power that can be supplied is determined based on the temperature increase rate of the heating roller 36 </ b> B when power is supplied from the power supply 58. Specifically, when the predetermined state is detected, the power supply from the power source 58 to the heating roller 36B is actually started based on the temperature increase rate and the temperature of the heating roller 36B. From the present time, the electric power from the power source 58 to the heating roller 36B is set so that the temperature of the heating roller 36B reaches the target temperature for heating the paper 31 during the period until the image formation is predicted to be started. A power supply start period, which is a period until the supply is started, is derived, and the power supply 58 is controlled so that power supply is started after the derived power supply start period has elapsed.

  As schematically illustrated in FIG. 6 as an example, the image forming apparatus 10 according to the present embodiment is applicable to the type of paper 31 that is the target of use in the image forming apparatus 10 and the image forming apparatus 10. Information indicating the target temperature γ to be applied for each combination with the operation mode of the image forming operation being performed (hereinafter referred to as “target temperature information”) is stored in advance in a predetermined area of the flash memory 43, and this embodiment In the power supply start optimization function according to the embodiment, the target temperature γ is set based on the target temperature information.

  In the target temperature information shown in FIG. 6, the target temperature γ increases in the order of the set operation mode of the monochrome mode, the two-color mode, and the full-color mode, and the type of the paper 31 to be used is plain paper, cardboard, It is assumed that the target temperature γ increases in the order of the OHP sheets.

  In the image forming apparatus 10 according to the present embodiment, a temperature increase rate deriving process for deriving a temperature increase rate of the heating roller 36B of the fixing unit 36, and an image forming operation for the paper 31 in order to realize the power supply start optimization function. Operation average time derivation for deriving an average time (hereinafter referred to as “operation average time”) from when a predetermined state predicted to be executed is detected until an input operation of an actual image formation execution instruction is performed. Three processes of a process and a power supply control process for controlling the power supply to the heating roller 36B of the fixing device 36 are executed.

  In the image forming apparatus 10 according to the present embodiment, the default value of the operation average time t0 is stored in advance in a predetermined area of the flash memory 43, and the operation average time t0 is appropriately updated by the operation average time derivation process. The value is updated. In the image forming apparatus 10 according to the present embodiment, an actual image forming execution instruction is input after a predetermined state in which execution of the image forming operation is predicted is detected as the default value of the operation average time t0. Although the statistical average value of the time until the operation is performed is applied, the present invention is not limited to this, and may be set by the user.

  Next, as the operation of the image forming apparatus 10 according to the present embodiment, first, the operation of the image forming apparatus 10 when executing the temperature increase rate deriving process will be described in detail with reference to FIG. Note that FIG. 7 shows a case where the CPU 40 executes the temperature increase rate deriving process at a predetermined timing (in this embodiment, a timing when an instruction to execute the temperature increase rate deriving process is input via the display 14). 4 is a flowchart showing a flow of processing of a temperature increase rate derivation processing program to be executed, and the program is stored in advance in a predetermined area of the ROM.

  In step 100 in the figure, the temperature of the heating roller 36B of the fixing device 36 is acquired by acquiring the detected temperature from the temperature sensor 15A via the image forming engine control unit 54, and the temperature derives the temperature increase rate. It is determined whether or not the temperature is equal to or lower than a first threshold value (50 ° C. in the present embodiment) set in advance as the lower limit value of the temperature of the heating roller 36B. On the other hand, when the increase rate derivation processing program is terminated, when the determination is affirmative, the routine proceeds to step 102.

  In step 102, the power source 58 is controlled so as to start the power supply to the heating roller 36B of the fixing device 36, and in the next step 103, the process waits until the temperature of the heating roller 36B reaches the first threshold value. In step 104, time measurement using a built-in timer (not shown) is started, and in the next step 106, the upper limit value of the temperature of the heating roller 36B when the temperature of the heating roller 36B derives the rate of temperature increase. And waits until a predetermined second threshold value (100 ° C. in the present embodiment) is reached.

  In the next step 108, the power source 58 is controlled so as to stop the power supply to the heating roller 36B of the fixing device 36, and in the next step 110, the time measured by the timer at this time is determined by the temperature of the heating roller 36B. The time difference Δt from the first threshold value to the second threshold value is obtained as an indication, and the derived time difference Δt is stored in a predetermined area of the flash memory 43 in the next step 112.

  In the next step 114, it is determined whether or not the time difference Δt is stored in the flash memory 43 by a predetermined number (here, 10) or more by the processing in step 112. If the determination is negative, the temperature increase rate is derived. On the other hand, if the processing program is finished and the determination is affirmative, the routine proceeds to step 116.

In Step 116, the predetermined number of time differences Δt (that is, the predetermined number of time differences Δt retroactively from the time difference Δt stored in the immediately preceding processing of Step 112) from the time point stored closest to this time point is calculated. After reading from the flash memory 43, in the next step 118, an average value Δt _ave of the read time difference Δt is calculated.

In the next step 120, it calculates the temperature rise rate α by substituting the average value Delta] t _ave and the first threshold value T1 and the second threshold value T2 obtained by the above process the following equation (2), In the next step 122, the calculated temperature increase rate α is stored in a predetermined area of the flash memory 43, and then the temperature increase rate deriving process program is terminated.

次に、図８を参照して、上記給電制御処理を実行する際の画像形成装置１０の作用を詳細に説明する。なお、図８は、用紙３１に対する画像形成動作の実行が予測される予め定められた状態が検出された場合にＣＰＵ４０によって実行される給電制御処理プログラムの処理の流れを示すフローチャートであり、当該プログラムもＲＯＭ４２の所定領域に予め記憶されている。また、ここでは、錯綜を回避するために、上記温度上昇率導出処理プログラムによって温度上昇率αがフラッシュメモリ４３に記憶されている場合について説明する。また、本実施の形態に係る給電制御処理プログラムでは、上記予め定められた状態として、原稿が上記画像読み取り位置に載置された状態、及び外部装置からの画像形成すべき画像を示す画像情報（所謂プリント・ジョブ）が受信された状態を適用しているが、これに限らず、複数の原稿を自動的に読み取ることが可能な自動原稿送り装置（所謂ＡＤＦ（Auto Document Feeder））を有する場合の当該自動原稿送り装置へ前記原稿が載置された状態、前記原稿を載置する領域を、当該原稿を載置した状態で覆うカバーを有する場合の当該カバーが開閉された状態等の、他の用紙３１に対する画像形成動作の実行が予測される状態の少なくとも１つを適用してもよい。

Next, the operation of the image forming apparatus 10 when executing the power supply control process will be described in detail with reference to FIG. FIG. 8 is a flowchart showing the flow of processing of the power supply control processing program executed by the CPU 40 when a predetermined state in which execution of the image forming operation on the paper 31 is predicted is detected. Is also stored in a predetermined area of the ROM 42 in advance. Here, a case will be described in which the temperature increase rate α is stored in the flash memory 43 by the temperature increase rate deriving processing program in order to avoid complications. Further, in the power supply control processing program according to the present embodiment, as the predetermined state, the state in which the document is placed at the image reading position and the image information indicating the image to be formed from the external device ( Although a state in which a so-called print job is received is applied, the present invention is not limited to this, and an automatic document feeder (so-called ADF (Auto Document Feeder)) capable of automatically reading a plurality of documents is provided. Others, such as a state where the original is placed on the automatic document feeder, a state where the cover is covered when the original is placed on the area where the original is placed, etc. At least one of the states in which the image forming operation is predicted to be performed on the paper 31 may be applied.

  In step 200 of the figure, timing using a built-in timer (not shown) is started, and in the next step 202, a state of waiting for an image forming operation at this time (a so-called sleep state or energy saving state, Hereinafter, it is referred to as “standby state”), and if negative determination is made, the process proceeds to step 204 and normal power feeding determined in advance corresponding to a state other than the standby state. After executing the control process, the power supply control process program is terminated.

  On the other hand, if the determination in step 202 is affirmative, the process proceeds to step 206 where the operation average time t0, the temperature increase rate α, and the target temperature information (see FIG. 6) described above are read from the flash memory 43. In step 208, the type of paper to be used and the image forming mode (in this embodiment, any one of the monochrome mode, the two-color mode, and the full-color mode) set at this point are detected.

  In the next step 210, the target temperature γ corresponding to the detected paper type and image forming mode is acquired from the target temperature information read out by the processing in step 206, and in the next step 212, the image forming engine control unit 54 is obtained. The temperature of the heating roller 36B at this time is acquired as the initial temperature β by acquiring the detected temperature from the temperature sensor 15A.

  In the next step 214, the power supply control processing program determines whether or not the power supply control processing program is started upon reception of image information. If the determination is affirmative, the process proceeds to step 216, and the processing in step 206 is performed. By substituting the operation average time t0 and the temperature increase rate α read out by the above, the target temperature γ acquired by the process of step 210 and the initial temperature β acquired by the process of step 212 into the following equation (3): After calculating the power supply start time t to the heating roller 36B of the fixing device 36, the routine proceeds to step 222.

なお、（３）式によって得られた給電開始時間ｔが負の値となる場合があるが、この場合は給電開始時間ｔを０（零）とする。

Note that the power supply start time t obtained by the expression (3) may be a negative value. In this case, the power supply start time t is set to 0 (zero).

  On the other hand, if a negative determination is made in step 214, the process proceeds to step 218, which is necessary to convert the image information into bitmap format data based on the amount of image to be formed based on the received image information. Decomposing time t1 is derived, and in the next step 220, the derived decomposing time t1, the temperature increase rate α, the target temperature γ, and the initial temperature β are substituted into the following equation (4): After calculating the power supply start time t to the heating roller 36B of the fixing device 36, the routine proceeds to step 222.

なお、（４）式によって得られた給電開始時間ｔが負の値となる場合があるが、この場合も給電開始時間ｔを０（零）とする。

Note that the power supply start time t obtained by the equation (4) may be a negative value. In this case, the power supply start time t is set to 0 (zero).

  In step 222, using a built-in timer (not shown) that is different from the timer that started timing in the process of step 200, the process waits until the calculated power supply start time t elapses, and the next step 224 is performed. Thus, the power source 58 is controlled so as to start power supply to the heating roller 36B of the fixing device 36.

  In the next step 226, after the power supply to the heating roller 36B is continued until the temperature of the heating roller 36B reaches the target temperature γ, feedback control is performed so that the temperature of the heating roller 36B becomes constant at the target temperature γ. The temperature of the heating roller 36B is set to a predetermined fixing temperature from the time when an execution instruction for image formation is input through the display 14 by the user of the image forming apparatus 10 or when the received image information is decomposed. A fixing temperature control process for controlling the power source 58 is executed.

  In the next step 228, the process waits until the timing for ending the fixing process arrives. In the next step 230, the power supply 58 is controlled so as to stop the power supply to the heating roller 36B, and then the main power supply is performed. The control processing program is terminated. Note that the timing for ending the fixing process applied in the process of step 228 is a timing when a predetermined time (one minute, for example) has passed since the last image formation is completed, and the power switch is turned off. One or a plurality of combinations such as a timing, a timing at which an abnormality in which the image forming operation cannot be continued in the image forming apparatus 10 occurs, and a timing at which the image forming operation is forcibly stopped by the user can be applied.

  By the way, the user of the image forming apparatus 10 places the document at the image reading position, and then performs various settings such as the number of copies of the document and the density setting via the display 14, and then inputs an instruction to execute image formation. To do. The operation average time deriving process is an interrupt process that is executed at the timing when this image formation execution instruction is input.

  Next, with reference to FIG. 9, the operation of the image forming apparatus 10 when executing the operation average time deriving process will be described in detail. FIG. 9 is a flowchart showing a process flow of an operation average time derivation process program executed by the CPU 40 at this time, and the program is also stored in a predetermined area of the ROM 42 in advance.

  In step 300 of FIG. 8, the time measured by the timer at this time is set in a predetermined state in which the execution of the image forming operation described above is predicted (in this embodiment, the document is placed at the image reading position. Is acquired as an indication of the elapsed time t from the point in time when the state or the state in which image information is received from the external device) is detected, and the acquired elapsed time t is stored in a predetermined area of the flash memory 43 in the next step 302. To do.

  In the next step 304, it is determined whether or not the elapsed time t is stored in the flash memory 43 by a predetermined number (here, 10) or more by the processing in the above step 302. On the other hand, when the derivation processing program is finished and the determination is affirmative, the routine proceeds to step 306.

  In step 306, the predetermined number of elapsed times t (that is, the predetermined number of elapsed times t retrospectively from the elapsed time t stored by the processing of step 302 immediately before the stored time point is closest to this time point). t) is read from the flash memory 43, and in the next step 308, the average value of the read elapsed time t is calculated as the operation average time t0.

  In the next step 310, the calculated operation average time t0 is overwritten and stored (updated) in a predetermined area of the flash memory 43, and then this operation average time derivation processing program is terminated.

[Second Embodiment]
In the second embodiment, the power supply 58 detects the magnitude of the power supplied to the heating roller 36B, and controls the power supply state of the power supply 58 to the heating roller 36B based on the detected power magnitude. An example of the case will be described.

  The appearance of the image forming apparatus according to the second embodiment and the internal configuration of the apparatus main body are the same as those of the image forming apparatus 10 according to the first embodiment (see FIGS. 1 and 2). First, the configuration of the main part of the electrical system of the image forming apparatus 10 ′ according to the second embodiment will be described with reference to FIG. 10 that are the same as in FIG. 3 are assigned the same reference numerals as in FIG. 3, and descriptions thereof are omitted.

  As shown in FIG. 10, the image forming apparatus 10 ′ according to the second embodiment detects the magnitude of the voltage supplied to the heating roller 36 </ b> B by the power source 58 and outputs it to the CPU 40. Is different from the image forming apparatus 10 according to the first embodiment only in that it is newly provided.

  In the image forming apparatus 10 ′ according to the second exemplary embodiment, as schematically illustrated in FIG. 11 as an example, a combination of a detection voltage by the voltage detection unit 60 and a power supply start time t corresponding thereto is used. Information (hereinafter referred to as “power supply start time information”) is stored in advance in a predetermined area of the flash memory 43. In the power supply start optimization function according to the second embodiment, detection by the voltage detection unit 60 is performed. A power supply start time t is set based on the result.

  In the image forming apparatus 10 ′ according to the present embodiment, in order to realize the power supply start optimization function, the temperature increase rate derivation process and the operation average time executed in the image forming apparatus 10 according to the first embodiment. The derivation process is not executed, and only the power supply control process is executed.

  Therefore, as an operation of the image forming apparatus 10 ′ according to the present embodiment, the operation of the image forming apparatus 10 ′ when executing the power supply control process will be described in detail with reference to FIG. 12. FIG. 12 shows the flow of processing of the power supply control processing program executed by the CPU 40 of the image forming apparatus 10 ′ when a predetermined state in which execution of the image forming operation on the paper 31 is predicted is detected. This is a flowchart, and the program is stored in a predetermined area of the ROM 42 in advance. Also in the power supply control processing program according to the present embodiment, as the predetermined state, image information (a state where an original is placed at the image reading position and an image to be imaged from an external device ( The state in which a so-called print job is received is applied, but the present invention is not limited to this, and the automatic document feeding in the case of having an automatic document feeding device (so-called ADF) capable of automatically reading a plurality of documents. An image on another sheet 31 such as a state where the document is placed on the apparatus, a state where the cover is covered when the document is placed on a region where the document is placed. At least one of the states in which the formation operation is predicted to be performed may be applied.

  In step 400 of the figure, it is determined whether or not it is in a standby state at this time, and if a negative determination is made, the process proceeds to step 402 and is determined in advance corresponding to a state other than the standby state. After executing the normal power supply control process, the power supply control process program is terminated.

  On the other hand, if the determination in step 400 is affirmative, the process proceeds to step 404 where the above-described energization start time information (see FIG. 11) and the above-described target temperature information (see FIG. 6) are read from the flash memory 43. In the next step 406, the type of paper to be used and the image forming mode (in this embodiment, either the monochrome mode, the two-color mode, or the full-color mode) detected at this point are detected. .

  In the next step 408, the target temperature γ corresponding to the detected paper type and image forming mode is acquired from the target temperature information read out by the processing in step 404, and detected in the next step 410 from the voltage detection unit 60. By acquiring the voltage value that has been set, the voltage V supplied from the power source 58 to the heating roller 36B at this time is detected.

  In the next step 412, the power supply start time t corresponding to the voltage V detected by the process of step 410 is acquired from the energization start time information read by the process of step 404.

  In the next step 414, a built-in timer (not shown) is used to wait until the acquired power supply start time t elapses, and in the next step 416, power supply to the heating roller 36B of the fixing device 36 is started. Thus, the power supply 58 is controlled.

  In the next step 418, after the power supply to the heating roller 36B is continued until the temperature of the heating roller 36B reaches the target temperature γ, feedback control is performed so that the temperature of the heating roller 36B becomes constant at the target temperature γ. The temperature of the heating roller 36B is set to a predetermined fixing temperature from the time when an execution instruction for image formation is input through the display 14 by the user of the image forming apparatus 10 or when the received image information is decomposed. A fixing temperature control process for controlling the power source 58 is executed.

  In the next step 420, the process waits until the timing for ending the fixing process arrives. In the next step 422, the power supply 58 is controlled so as to stop the power supply to the heating roller 36B of the fixing device 36, and then the main power supply is performed. The control processing program is terminated. Note that the timing for ending the fixing process applied in the process of step 420 is the same as the power supply control process program according to the first embodiment (see also FIG. 8). The timing when a predetermined time (for example, 1 minute) or more has elapsed, the timing when the power switch is turned off, the timing when an abnormality that prevents the image forming operation from continuing in the image forming apparatus 10 occurs, and the image forming operation is forced by the user One or a plurality of combinations such as the timing at which the operation is stopped can be applied.

  As described above in detail, in each of the above-described embodiments, when a predetermined state in which the execution of the image forming operation on the recording medium (here, the paper 31) is predicted is detected, the supply unit (here, The power supply 58) controls the supply means so that the power supply to the heating means (here, the heating roller 36B) becomes larger as the power supply to the heating means is delayed.

  In each of the above embodiments, when the predetermined state is detected, if the power that can be supplied to the heating unit by the supply unit is equal to or higher than the predetermined power, the power to the heating unit The supply means is controlled so as to delay the start of supply compared to the case where the supply is less than the predetermined power.

  Moreover, in the said 1st Embodiment, the magnitude | size of the said electric power which can be supplied is judged based on the temperature rise rate of the said heating means when electric power is supplied by the said supply means.

  In the first embodiment, when the predetermined state is detected, the temperature increase rate acquired by the acquisition unit (here, the CPU 40) and the measurement unit (here, the temperature sensor 15A) are used. Based on the measured temperature, the temperature of the heating unit is recorded during the period from when the supply of power from the supply unit to the heating unit is started until it is predicted that the image formation is actually started. A power supply start period (here, power supply start time t) that is a period from the present time to the start of power supply from the supply means to the heating means so as to reach the target temperature for heating the medium. The supply means is controlled to start power supply after the derived power supply start period elapses.

In the first embodiment, the temperature increase rate is α, the temperature measured by the measuring unit is β, the target temperature is γ, and the predetermined state is detected before the temperature is detected. The power supply start period t is calculated by the above equation (1), where t _x is the period until the time when the image formation is actually expected to start.

  In each of the above embodiments, the type of the recording medium and the type of image forming mode are acquired, and the target temperature is determined based on the acquired type.

  In the second embodiment, the detection unit (here, the voltage detection unit 60) that detects the magnitude of the power supplied to the heating unit by the supply unit is detected and detected by the detection unit. The control is performed based on the magnitude of the power.

  In each of the above embodiments, the control is performed when the predetermined state is detected and when an image forming operation for the recording medium is awaited.

  In each of the above embodiments, as the predetermined state, a state in which a predetermined operation performed as a pre-stage of an instruction to execute image formation is performed by the user, and an image is formed from an external device. Both of the states in which image information (in this case, a print job) indicating a power image is received are applied.

  In each of the above embodiments, an operation for placing a document at a predetermined reading position is applied as the predetermined operation.

  Further, in each of the above-described embodiments, an image carrier (here, the photosensitive drum 22) on which an electrostatic latent image is formed and held, and the electrostatic latent image formed on the image carrier using a developer. A developing unit (here, developing unit 28) that develops a visible image; and a transferring unit (here, transfer unit 34) that transfers the visible image on the image holding member to the recording medium. However, fixing means (here, a heating roller 36B) is used to fix the visible image transferred to the recording medium by heating the recording medium.

  As mentioned above, although this invention was demonstrated using the said embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. Various changes or improvements can be added to the above-described embodiment without departing from the gist of the invention, and embodiments to which the changes or improvements are added are also included in the technical scope of the present invention.

  The above embodiments do not limit the invention described in the claims, and all combinations of features described in the above embodiments are indispensable for the solution means of the invention. Not always. The above-described embodiments include inventions at various stages, and various inventions are extracted by combinations according to situations in a plurality of disclosed constituent requirements. Even if some constituent features are deleted from all the constituent features shown in the above embodiment, the configuration from which these constituent features are deleted is extracted as an invention as long as the effect is obtained.

  For example, in the first embodiment, the magnitude of power that can be supplied to the heating roller 36B by the power source 58 is determined based on the temperature increase rate α of the heating roller 36B when power is supplied by the power source 58. However, the present invention is not limited to this. For example, the present invention is based on the configuration state of other driving parts such as a finisher, a tray module, and an ADF that are driven by power supplied from the power source 58. It is also possible to make a judgment form.

  In each of the above embodiments, as the predetermined state, a state in which a predetermined operation performed as a pre-stage of an instruction to execute image formation is performed by the user, and an image is formed from an external device. Although the case where both of the image information (here, the print job) indicating the power image is received has been described, the present invention is not limited to this and any one of these is applied. It is good also as a form.

  In each of the above embodiments, the case where the present invention is applied to a fixing unit of an image forming apparatus that forms an image by an electrophotographic method has been described. However, the present invention is not limited to this, and the present invention is not limited thereto. For example, the present invention may be applied to a drying unit that dries a recording medium on which an image is formed by droplets of a droplet discharge device (so-called inkjet printer).

  In each of the above-described embodiments, the case where various programs are stored in advance in the ROM 42 has been described. However, the present invention is not limited to this, and these programs are stored in a CD-ROM, a DVD-ROM, or a USB. A form provided in a state of being stored in a computer-readable recording medium such as a memory may be applied, or a form distributed via wired or wireless communication means may be applied.

  In each of the above embodiments, the case where the power supply start optimization function is activated when the image forming apparatus is in the standby state has been described. However, the present invention is not limited to this, and the power switch is turned on. Needless to say, the power supply start optimization function may be used when the image forming apparatus is not in a standby state, such as when the image forming operation ends immediately before or when the image forming apparatus is in a standby state.

  In each of the above embodiments, the case where the target temperature γ is determined based on both the type of the paper 31 and the type of the image forming mode has been described. However, the present invention is not limited to this, and these The target temperature γ may be determined based on only one of them.

  In addition, the configuration of the image forming apparatus described in the above embodiments (see FIGS. 1 to 3 and 10) is merely an example, and unnecessary portions may be deleted without departing from the gist of the present invention. A new part may be added, or the arrangement position of each part may be changed.

  The processing flow of various programs described in the above embodiments (see FIGS. 7 to 9 and 12) is also an example, and unnecessary steps can be deleted without departing from the scope of the present invention. A new step may be added or the processing order may be changed.

  Furthermore, the configuration of the target temperature information and the power supply start time information (see FIGS. 6 and 11) shown in the above embodiments is also an example, and can be changed as appropriate without departing from the gist of the present invention. Needless to say, it is good.

1 is a front view of an image forming apparatus according to an embodiment. 1 is a schematic cutaway side view showing a configuration of main parts inside an image forming apparatus according to an embodiment. 1 is a block diagram showing a main configuration of an electric system of an image forming apparatus according to a first embodiment. 6 is a graph for explaining power supply control for a heating roller in a conventional image forming apparatus. 6 is a graph showing an example of the relationship between the elapsed time from the start of power feeding and the temperature of the heating roller at different supplyable voltages from the power source to the heating roller in the image forming apparatus according to the embodiment. It is a schematic diagram which shows the structure of the target temperature information which concerns on embodiment. It is a flowchart which shows the flow of a process of the temperature increase rate derivation | leading-out processing program which concerns on 1st Embodiment. It is a flowchart which shows the flow of a process of the electric power feeding control processing program which concerns on 1st Embodiment. It is a flowchart which shows the flow of a process of the operation average time derivation | leading-out processing program which concerns on 1st Embodiment. FIG. 5 is a block diagram illustrating a main configuration of an electrical system of an image forming apparatus according to a second embodiment. It is a schematic diagram which shows the structure of the electric power feeding start time information which concerns on 2nd Embodiment. It is a flowchart which shows the flow of a process of the electric power feeding control processing program which concerns on 2nd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10,10 'Image forming apparatus 11 Scanner 11A Document detection sensor 12 Main body 13 Paper feeder 14 Touch panel display 15 Image forming engine part 15A Temperature sensor (measuring means)
22 Photosensitive drum (image carrier)
28 Developer (Developer)
30A to 30D Paper feed tray 31 Paper (recording medium)
34 Second transfer device (transfer means)
36 Fixing device 36B Heating roller (heating means, fixing means)
39 discharge tray 40 CPU (control means, acquisition means, type acquisition means)
41 RAM
42 ROM
43 Flash memory 58 Power supply (supply means)
60 Voltage detector (detection means)

Claims (13)

Heating means for heating the recording medium on which the image is formed;
Supply means for supplying heating power to the heating means;
When a predetermined state in which execution of an image forming operation on the recording medium is predicted is detected, the start of power supply to the heating unit is delayed as the power that can be supplied to the heating unit by the supply unit increases. Control means for controlling the supply means to:
An image forming apparatus. When the predetermined state is detected, the control unit starts power supply to the heating unit when the power that can be supplied to the heating unit by the supply unit is equal to or higher than the predetermined power. The image forming apparatus according to claim 1, wherein the supply unit is controlled to be slower than when the power is less than the predetermined power. The control means determines the magnitude of the power that can be supplied, the temperature increase rate of the heating means when power is supplied by the supply means, or another drive that is driven by power supplied from the supply means The image forming apparatus according to claim 1, wherein the determination is based on a configuration state of the part. An acquisition means for acquiring a temperature increase rate of the heating means when power is supplied to the heating means by the supply means;
Measuring means for measuring the temperature of the heating means or the temperature in the vicinity of the heating means;
Further comprising
When the predetermined state is detected, the control unit is configured to supply power from the supply unit to the heating unit based on the temperature increase rate acquired by the acquisition unit and the temperature measured by the measurement unit. From the present time so that the temperature of the heating means reaches the target temperature for heating the recording medium in a period from when the supply of the recording medium is started until it is predicted that the image formation is actually started. The control is performed by deriving a power supply start period that is a period until the start of power supply from the means to the heating means, and controlling the supply means to start power supply after the derived power supply start period has elapsed. The image forming apparatus according to any one of claims 1 to 3. The control means sets the temperature rise rate as α, the temperature measured by the measuring means as β, the target temperature as γ, and the actual image formation after the predetermined state is detected. The power supply start period t is calculated by the following arithmetic expression, where t _x is the period until the time when the start is predicted.

The image forming apparatus according to claim 4. A type acquisition means for acquiring at least one of the type of the recording medium and the type of image forming mode;
The image forming apparatus according to claim 4, wherein the control unit determines the target temperature based on a type acquired by the type acquisition unit. Further comprising a detecting means for detecting the magnitude of the power supplied to the heating means by the supplying means,
The image forming apparatus according to claim 1, wherein the control unit performs the control based on a magnitude of electric power detected by the detection unit. 8. The control unit according to claim 1, wherein the control unit performs the control when the predetermined state is detected and when waiting for an image forming operation on the recording medium. Image forming apparatus. The predetermined state includes a state in which a predetermined operation performed as a pre-stage of an image formation execution instruction is performed by the user, and image information indicating an image to be formed from an external device is received. The image forming apparatus according to claim 1, wherein the image forming apparatus is at least one of the two states. The predetermined operation is an operation of placing the document at a predetermined reading position when reading an image recorded on the document and forming the image on the recording medium, and placing the document. The operation of opening and closing the cover in the case of having a cover that covers the area with the document placed thereon, and the automatic document feeder in the case of having an automatic document feeder capable of automatically reading a plurality of documents The image forming apparatus according to claim 9, wherein the image forming apparatus is at least one of an operation of placing the document on a document. An image carrier on which an electrostatic latent image is formed and held;
Developing means for developing the electrostatic latent image formed on the image carrier into a visible image with a developer;
Transfer means for transferring a visible image on the image carrier to the recording medium;
Further comprising
The image forming apparatus according to claim 1, wherein the heating unit is a fixing unit that fixes a visible image transferred to the recording medium by heating the recording medium. . A program executed in an image forming apparatus comprising: a heating unit that heats a recording medium on which an image is formed; and a supply unit that supplies heating power to the heating unit.
Computer
When a predetermined state in which execution of an image forming operation on the recording medium is predicted is detected, the start of power supply to the heating unit is delayed as the power that can be supplied to the heating unit by the supply unit increases. A program for causing the supply means to function as control means.   The program for functioning a computer as a control means in the image forming apparatus of any one of Claims 1-11.

Images