Image forming apparatus and image forming method

Abstract

To quickly shift to image formation processing even when a roller of an image formation unit is rotated at a speed different from the full speed in the image formation processing executed according to image formation data.SOLUTION: An image formation apparatus (1) comprises: an image formation unit (10) which forms an image on a sheet according to image formation data; and a CPU (111) which executes reception processing (S110) of receiving a preceding command transmitted from an external terminal (2) prior to the image formation data, rotational speed determination processing (S120) of determining the rotational speed of a heating roller (105a) of the image formation unit (10) from option information included in the preceding command and preparation processing (S130) of rotating the heating roller (105a) before the image formation unit (10) starts the image formation. The CPU (111) controls a motor (M) that drives the heating roller (105a) in the preparation processing (S130) such that the heating roller (105a) is rotated at the rotational speed determined in the rotational speed determination processing (S120).SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an image forming apparatus and an image forming method for forming an image on a sheet. [Background technology]

[0002] In an image forming apparatus, a technique has been proposed for shortening the time from when an image formation command is issued until the trailing edge of the first sheet is discharged, that is, the so-called first print time. For example, an image forming apparatus has been proposed that starts preparation processing when triggered by a preceding command received prior to image formation data. Examples of the preparation processing include rotating a heating roller of a fixing unit and increasing the temperature of a heater of the fixing unit.

[0003] In the printer device described in Patent Document 1, the first print time is shortened by spooling print data and warming up the printer device in parallel. The warming up process in the printer device described in Patent Document 1 is started with the start-up data received prior to the print data as a trigger. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2001-150761 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the preparatory process executed according to the preceding command, the rollers for conveying the sheet were conventionally rotated at full speed at all times. Therefore, when the rollers are rotated at a speed different from full speed, for example at half speed, in the image forming process executed according to the image forming data, it is necessary to switch the rotation speed of the motor driving the rollers when shifting from the preparatory process to the image forming process. Therefore, there is a problem that it takes extra time to shift from the preparatory process to the image forming process.

[0006] One aspect of the present invention aims to provide an image forming apparatus and an image forming method that are capable of quickly transitioning to image formation processing even when the roller is rotated at a speed other than full speed in image formation processing performed in accordance with image formation data. [Means for solving the problem]

[0007] An image forming apparatus according to one embodiment of the present invention comprises an image forming unit that forms an image on a sheet in accordance with image formation data transmitted from an external terminal, the image forming unit having a roller that transports a sheet and a drive unit that rotates the roller at a predetermined speed by applying a driving force to the roller, and a control unit, wherein the control unit executes an acquisition process that acquires a preceding command transmitted from the external terminal prior to the image formation data, a determination process that determines the rotation speed of the roller from optional information included in the preceding command, and a preparatory process that controls the drive unit to rotate the roller at the rotation speed determined in the determination process before the image forming unit starts image formation.

[0008] According to the above configuration, the rotation speed of the roller in the preparatory process can be made to coincide with the rotation speed of the roller in the image forming process, so that there is no need to change the rotation speed of the roller when transitioning from the preparatory process to the image forming process, and therefore transition from the preparatory process to the image forming process can be made quickly.

[0009] In an image forming apparatus according to one embodiment of the present invention, the control unit executes the preparatory process when the rotation speed determined in the determination process is a first speed, and does not execute the preparatory process when the rotation speed determined in the determination process is a second speed different from the first speed.

[0010] According to the above configuration, when the rotation speed of the roller in the image forming process is the second speed, the preparatory process is omitted, so there is no need to change the rotation speed of the roller from the first speed to the second speed when transitioning to the image forming process. Therefore, the transition to the image forming process can be performed quickly. In addition, it is possible to avoid the generation of noise caused by rotating the roller at the first speed in the preparatory process.

[0011] In an image forming apparatus according to one embodiment of the present invention, the control unit controls the drive unit in the preparation process so that the roller rotates at a first speed when the rotation speed determined in the determination process is a first speed, and controls the drive unit in the preparation process so that the roller rotates at the second speed when the rotation speed determined in the determination process is a second speed different from the first speed.

[0012] According to the above configuration, when the rotation speed of the roller in the image forming process is the second speed, the rotation speed of the roller in the preparation process is also controlled to the second speed, so that there is no need to change the rotation speed of the roller from the first speed to the second speed when transitioning to the image forming process. Therefore, the transition to the image forming process can be performed quickly. In addition, the noise generated by rotating the roller at the first speed in the preparation process can be reduced.

[0013] In an image forming apparatus according to one embodiment of the present invention, the option information includes designation information that designates at least one of a sheet size, a sheet type, and an image forming mode, and in the determination process, the control unit determines the rotation speed of the roller based on the designation information.

[0014] According to the above configuration, the rotation speed of the rollers in the preparation process can be appropriately set according to the sheet size, the sheet type, and the image forming mode.

[0015] In an image forming device according to one embodiment of the present invention, in the determination process, the control unit determines the rotation speed of the roller based on internal designation information stored in the image forming device, which designates the image forming mode, in addition to the designation information contained in the option information.

[0016] According to the above configuration, the rotation speed of the roller in the preparation process can be appropriately set in accordance with the image forming mode designated by the internal designation information stored in the image forming apparatus.

[0017] In an image forming device according to one embodiment of the present invention, when the option information does not include designation information specifying the image formation mode during the determination process, the control unit determines the rotation speed of the roller based on the designation information stored in the image forming device that specifies the image formation mode, in addition to the designation information included in the option information.

[0018] According to the above configuration, even if the preceding command does not include specification information specifying an image formation mode, the rotation speed of the roller in the preparatory process can be appropriately set in accordance with the image formation mode specified by the internal specification information stored in the image forming device.

[0019] In an image forming apparatus according to one embodiment of the present invention, the option information includes designation information that specifies whether the rotation speed of the roller should be a first speed or a second speed different from the first speed, and in the decision process, the control unit decides whether the rotation speed of the roller should be the first speed or the second speed in accordance with the designation information.

[0020] According to the above configuration, when the external terminal has the function of determining the rotation speed of the roller in the preparatory processing, an image forming device can be realized that can quickly transition from the preparatory processing to the image forming processing.

[0021] In the image forming apparatus according to one aspect of the present invention, the image forming section includes a heater and a heating roller heated by the heater, and the roller is the heating roller.

[0022] An image forming method according to one embodiment of the present invention includes an acquisition process that acquires a preceding command transmitted from an external terminal prior to image formation data, a determination process that determines the rotation speed of a roller in an image forming unit from optional information included in the preceding command, a preparation process that rotates the roller before the image forming unit starts image formation, and an image formation process that uses the image forming unit to form an image on a sheet in accordance with the image formation data, and controls a drive unit that drives the roller in the preparation process so that the roller rotates at the rotation speed determined in the determination process.

[0023] According to the above method, the rotation speed of the roller in the preparatory process can be made to coincide with the rotation speed of the roller in the image forming process, so that there is no need to change the rotation speed of the roller when transitioning from the preparatory process to the image forming process, and therefore the transition from the preparatory process to the image forming process can be made quickly. Effect of the Invention

[0024] According to one aspect of the present invention, even when the rollers of the image forming unit are rotated at a speed other than full speed during image formation processing performed in accordance with image formation data, it is possible to quickly transition to image formation processing. [Brief description of the drawings]

[0025] [Figure 1] 1 is a block diagram showing a configuration of an image forming system according to an embodiment of the present invention; [Diagram 2] 2 is a diagram showing an internal configuration of an image forming apparatus included in the image forming system of FIG. 1. [Diagram 3] 3 is a block diagram showing an internal configuration of the image forming apparatus of FIG. 2. [Figure 4]4 is a flowchart showing the flow of operations of an external terminal included in the image forming system of FIG. [Diagram 5] 4 is a flowchart showing the flow of operations of the image forming apparatus in FIG. 3. [Figure 6] 6 is a flowchart showing a specific example of a rotation speed determination process included in the flowchart of FIG. 5. [Figure 7] 6 is a flowchart showing a specific example of the preparation process included in the flowchart of FIG. 5. [Figure 8] 6 is a flowchart showing a specific example of the image forming process included in the flowchart of FIG. 5. [Figure 9] 6 is a flowchart showing a specific example of an image formation ending process included in the flowchart of FIG. 5. [Figure 10] 4 is a timing chart showing an example of the operation of the image forming apparatus in FIG. 3. [Figure 11] 7 is a flowchart showing a modified example of the operation of the image forming apparatus in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] Hereinafter, this embodiment will be described with reference to the drawings.

[0027] (Configuration of Image Forming System) An image forming system 3 according to an embodiment of the present invention will be described with reference to Fig. 1. Fig. 1 is a block diagram showing the configuration of the image forming system 3.

[0028] The image forming system 3 includes an image forming apparatus 1 and an external terminal 2 communicably connected to the image forming apparatus 1. The image forming apparatus 1 is an apparatus for forming an image on a sheet. The external terminal 2 is an apparatus for instructing the image forming apparatus 1 to form an image on a sheet. In this embodiment, an MFP (Multi-Function Peripheral) is used as the image forming apparatus 1. Also, a PC (Personal Computer) is used as the external terminal 2.

[0029] 1 illustrates an example of the image forming system 3 including one external terminal 2, but is not limited to this. That is, the image forming system 3 may include two or more external terminals 2. The image forming system 3 may also include an external terminal 2 other than a PC, such as a smartphone or a tablet.

[0030] (Configuration of Image Forming Apparatus) The configuration of the image forming apparatus 1 will be described with reference to Fig. 2 and Fig. 3. Fig. 2 is a diagram showing the internal physical configuration of the image forming apparatus 1. Fig. 3 is a block diagram showing the configuration of the image forming apparatus 1.

[0031] 2, the image forming apparatus 1 further includes a main body housing 16, a sheet supply unit 17, a discharge roller 18, and a discharge tray 19. The main body housing 16 accommodates the above-mentioned components.

[0032] The sheet supply unit 17 feeds out the sheet S. The sheet supply unit 17 includes a tray 171, a feed roller 172, a sheet pressing plate 173, a transport roller 174, and a registration roller 175. The tray 171 is a sheet tray that stores the sheet S. The feed roller 172 is a feed roller that feeds out the sheet S stored in the tray 171.

[0033] When the sheet S is sent out, the sheet S on the tray 171 is brought to the feed roller 172 by the sheet pressing plate 173, and is fed to the conveying roller 174 as the feed roller 172 rotates. The conveying roller 174 conveys the sheet S toward the registration roller 175. The registration roller 175 aligns the position of the leading edge of the sheet S, and then conveys the sheet S toward the image forming unit 10. The image forming unit 10 forms an image on the sheet S sent out by the sheet supply unit 17. The sheet S with the image formed is discharged onto the discharge tray 19 by the discharge roller 18.

[0034] 2 and 3, the configuration and operation of the image forming unit 10 will be further described. The image forming unit 10 includes an exposure unit 102, a transfer unit 104, a charging unit 101, a developing unit 103, a fixing unit 105, and a photoconductor 100. The exposure unit 102 includes a laser light source (not shown), a polygon mirror 102G, a scanning lens 102L, a polygon motor 102M, and a reflecting mirror 102R.

[0035] The polygon mirror 102G is a rotating polygonal mirror having six reflecting surfaces on the side surfaces of a regular hexagonal prism. The polygon mirror 102G is for deflecting the light beam L1 emitted from the laser light source in a direction toward the photoconductor 100. The polygon motor 102M drives the polygon mirror 102G to rotate. A motor driver (not shown) provided in the exposure unit 102 drives the polygon motor 102M.

[0036] The exposure unit 102 deflects the light beam L1 by a polygon mirror 102G, and emits the light beam L1 from the polygon mirror 102G to the surface of the photoconductor 100 via a scanning lens 102L and a reflecting mirror 102R. The exposure unit 102 scans and exposes the surface of the photoconductor 100 with the light beam L1. As a result, an electrostatic latent image is formed on the photoconductor 100. The polygon motor 102M is a brushless DC motor.

[0037] The transfer unit 104 is a transfer roller that sandwiches the sheet S between itself and the photoconductor 100. The charging unit 101 is a scorotron type charger having a charging wire and a grid unit (not shown). A charging voltage is applied to the charging wire by a high voltage generating circuit (not shown), and a grid voltage is applied to the grid unit, generating a corona discharge, and the surface of the photoconductor 100 is uniformly charged. The developing unit 103 includes a developing roller 103R and a developer container 103A.

[0038] In the image forming unit 10, the surface of the photoconductor 100 is uniformly charged by the charging unit 101, and then an electrostatic latent image based on image data is formed on the photoconductor 100 by a light beam L1 from an exposure unit 102. In addition, the developing roller 103R supplies the developer in the developer container 103A to the photoconductor 100 on which the electrostatic latent image has been formed. This makes the electrostatic latent image visible, and a developer image is formed on the photoconductor 100. Thereafter, the sheet S supplied from the sheet supply unit 17 is transported to a transfer position between the photoconductor 100 and the transfer unit 104, and the developer image formed on the photoconductor 100 is transferred onto the sheet S.

[0039] The sheet S onto which the developer image has been transferred is transported to a fixing unit 105 by the photoconductor 100 and the transfer unit 104. The fixing unit 105 thermally fixes the developer image on the sheet S transported from the photoconductor 100 and the transfer unit 104. The fixing unit 105 includes a heating roller 105a, a pressure roller 105c, and a heater H. The fixing unit 105 uses the heater H to heat the sheet S on which the image has been formed.

[0040] The heating roller 105a heats the sheet S. The pressure roller 105c sandwiches the sheet S between the heating roller 105a and the pressure roller 105c. A heater H is disposed inside the heating roller 105a to raise the temperature of the heating roller 105a. The heater H is, for example, a halogen lamp. In the fixing section 105, the sheet S on which the developer image has been transferred is sandwiched between the heating roller 105a and the pressure roller 105c and conveyed, whereby the developer image is thermally fixed onto the sheet S. The sheet S on which the developer image has been thermally fixed is discharged onto a discharge tray 19 by discharge rollers 18. The heating roller 105a is an example of a "roller" in the claims.

[0041] 3, the image forming apparatus 1 includes an image forming unit 10, an ASIC (Application Specification Integrated Circuit) 11, a ROM (Read Only Memory) 12, a RAM (Random Access Memory) 13, a LAN (Local Area Network) interface 14, and an operation panel 15. The image forming unit 10, the ASIC 11, the ROM 12, the RAM 13, the LAN interface 14, and the operation panel 15 are connected to each other via a bus.

[0042] The image forming unit 10 is configured to form an image on a sheet S. In this embodiment, the image forming unit 10 includes a charging unit 101, an exposure unit 102, a developing unit 103, a transfer unit 104, and a fixing unit 105, as shown in FIGS.

[0043] The charging unit 101 is configured to uniformly charge the surface of the photoconductor 100. The exposure unit 102 is configured to form an electrostatic latent image on the uniformly charged surface of the photoconductor using a light beam. The developing unit 103 is configured to visualize the electrostatic latent image formed on the surface of the photoconductor 100 using a developer. The transfer unit 104 is configured to transfer the developer image formed on the surface of the photoconductor 100 to the surface of the sheet S using a transfer roller. The fixing unit 105 is configured to thermally fix the developer image transferred to the surface of the sheet S using a heating roller 105a as described above.

[0044] The temperature of the heating roller 105a is increased by passing electricity through the heater H. The heating roller 105a is provided with a driving force by the rotation of a motor M. The rotation speed of the motor M, i.e., the rotation speed of the heating roller 105a, is controlled by a motor driver 105b that drives the motor M. The motor driver 105b is an example of a "drive unit" in the claims.

[0045] A CPU (Central Processing Unit) 111 is built into the ASIC 11. The CPU 111 is configured to control each part of the image forming apparatus 1, for example, the image forming unit 10 described above and the operation panel 15 described below. The ROM 12 stores various programs and various parameters for controlling each part of the image forming apparatus 1. The CPU 111 controls each part of the image forming apparatus 1 according to the programs stored in the ROM 12 while referring to the parameters stored in the ROM 12. The CPU 111 functions as a control unit of the image forming apparatus 1, and the ROM 12 functions as a storage unit of the image forming apparatus 1.

[0046] The LAN interface 14 is configured to receive various commands and various data from the external terminal 2. Examples of the commands and data that the LAN interface 14 receives from the external terminal 2 include a preceding command and image formation data, which will be described later. The RAM 13 is provided with a buffer 131 and a page memory 132. The buffer 131 is configured to temporarily store various commands and various data received by the LAN interface 14. For example, the preceding command and image formation data received by the LAN interface 14 from the external terminal 2 are temporarily stored in the buffer 131. The page memory 132 is configured to temporarily store data generated by the CPU 111. For example, raster data generated by the CPU 111 from the image formation data is temporarily stored in the page memory 132. The RAM 13 functions as a storage unit of the image forming apparatus 1, and the LAN interface 14 functions as a communication unit of the image forming apparatus 1.

[0047] Operation panel 15 is configured to receive user operations. Operation panel 15 is configured, for example, with touch panel unit 151 and push button unit 152. Touch panel unit 151 is configured with a display and a touch pad, and displays an operation screen acquired from CPU 111 on the display, and supplies a signal representing a touch operation detected by the touch pad to CPU 111. Push button unit 152 is configured with a plurality of push buttons, and supplies a signal representing a push operation detected by each push button to CPU 111.

[0048] (External terminal operation) The operation of the external terminal 2 will be described with reference to Fig. 4. Fig. 4 is a flowchart showing the flow of the operation of the external terminal 2.

[0049] When the image formation button is pressed (S201: YES), the external terminal 2 executes an option information creation process S202. The option information creation process S202 is a process for creating option information that indicates a method for forming an image in the image formation process. In this embodiment, the option information used includes sheet size designation information that designates a sheet size, sheet type designation information that designates a sheet type, and image formation mode designation information that designates an image formation mode.

[0050] The external terminal 2 then executes a preceding command transmission process S203. The preceding command transmission process S203 is a process for transmitting a preceding command including the option information created in the option information creation process S202 to the image forming apparatus 1 via a LAN. In this embodiment, a preceding command in which the option information is written in a printer job language (PJL) is used. The preceding command may be a command in a USB control transfer format.

[0051] The external terminal 2 then executes image formation data generation processing S204. The image formation data generation processing S204 is processing for generating image formation data that indicates a method for forming an image in the image formation processing and the contents of the image to be formed. In this embodiment, the method for forming an image is described in a printer job language, and image formation data in which the contents of the image to be formed are described in a page description language (PDL) is used. Note that the contents of the image to be formed may be described in accordance with PDF (Portable Document Format).

[0052] The external terminal 2 then executes an image formation data transmission process S205. The image formation data transmission process S205 is a process for transmitting the image formation data generated in the image formation data generation process S204 to the image forming apparatus 1 via a LAN. The image formation data generation process S204 and the image formation data transmission process S205 are executed for each page, and are repeated until the processes for all pages are completed (S206: YES).

[0053] In this embodiment, the configuration is adopted in which the external terminal 2 transmits the preceding command and image formation data to the image forming apparatus 1 via a LAN, but the present invention is not limited to this. For example, a configuration may be adopted in which the external terminal 2 transmits the preceding command and image formation data to the image forming apparatus 1 via a USB (Universal Serial Bus) cable. In this case, the preceding command and image formation data are transmitted to the image forming apparatus 1 as, for example, a USB command. Also, in this case, the image forming apparatus 1 is provided with a USB interface instead of the LAN interface 14, and receives the preceding command and image formation data by utilizing this USB interface.

[0054] (Operation of image forming device) The operation of the image forming apparatus 1 will be described with reference to Fig. 5. Fig. 5 is a flowchart showing the flow of the operation of the image forming apparatus 1. Note that, unless otherwise specified, the processing subject of each step described below is the image forming apparatus 1, more specifically, the CPU 111 of the image forming apparatus 1.

[0055] When the image forming apparatus 1 receives a preceding command transmitted from the external terminal 2 prior to the image formation data (S110: YES), it executes a rotation speed determination process S120. The rotation speed determination process S120 is a process for determining the rotation speed of the heating roller 105a in the preparation process S130 and the image formation process S140 described later, i.e., the rotation speed of the motor M, from option information included in the received preceding command. A specific example of the rotation speed determination process S120 will be described later with reference to different drawings.

[0056] In this embodiment, the rotation speed determined in the rotation speed determination process S120 is either a first speed or a second speed slower than the first speed. In the following, the first speed is assumed to be full speed and the second speed is assumed to be half speed, i.e., 50% of the full speed, but the present invention is not limited to this. For example, when the first speed is full speed, the second speed may be 75% of the full speed or 25% of the full speed.

[0057] The image forming apparatus 1 then executes a preparation process S130. The preparation process S130 is a process for increasing the temperature of the fixing unit 105 by rotating the heating roller 105a using the motor M and heating the heating roller 105a using the heater H. In the preparation process S130, the CPU 111 and the motor driver 105b of the image forming apparatus 1 control the motor M so that the heating roller 105a rotates at the rotation speed determined in the rotation speed determination process S120. For example, when the rotation speed determined in the rotation speed determination process S120 is half speed, the CPU 111 and the motor driver 105b of the image forming apparatus 1 control the motor M so that the heating roller 105a rotates at half speed. Also, when the rotation speed determined in the rotation speed determination process S120 is full speed, the CPU 111 and the motor driver 105b of the image forming apparatus 1 control the motor M so that the heating roller 105a rotates at full speed. A specific example of the preparation process S130 will be described later with reference to a different drawing.

[0058] The image forming apparatus 1 then executes an image forming process S140. The image forming process S140 is a process for forming an image on the sheet S in accordance with image formation data transmitted from the external terminal 2. As will be described later, the rotation speed of the heating roller 105a in the image forming process S140 matches the rotation speed of the heating roller 105a in the preparation process S130. Therefore, it is not necessary to change the rotation speed of the motor M when moving from the preparation process S130 to the image forming process S140. A specific example of the image forming process S140 will be described later with reference to different drawings.

[0059] The image forming apparatus 1 then executes an image formation end process S150. The image formation end process S150 is a process for stopping the rotation of the heating roller 105a using the motor M and stopping the heating of the heating roller 105a using the heater H. A specific example of the image formation end process S150 will be described later with reference to different drawings.

[0060] (Specific example of rotation speed determination process) A specific example of the rotation speed determination process S120 will be described with reference to Fig. 6. Fig. 6 is a flowchart showing a specific example of the rotation speed determination process S120. Note that, unless otherwise specified, the subject of processing in each step described below is the image forming apparatus 1, more specifically, the CPU 111 of the image forming apparatus 1.

[0061] In the rotation speed determination process S120, the image forming device 1 acquires option information included in the received preceding command (S121). As described above, this option information includes sheet size designation information, sheet type designation information, and image formation mode designation information. The image forming device 1 interprets the option information described in the printer job language to identify the sheet size designated by the sheet size designation information, the sheet type designated by the sheet type designation information, and the image formation mode designated by the image formation mode designation information.

[0062] The image forming apparatus 1 then determines whether the sheet size specified by the sheet size specification information included in the option information is small (S122). If the sheet size is small (S122: YES), the image forming apparatus 1 sets the rotation speed to half speed (S127). Note that the sheet size being small means, for example, that the sheet size is 1 cm or more smaller than the letter size.

[0063] If the sheet size is not small (S122: NO), the image forming apparatus 1 then determines whether the sheet type specified by the sheet type specification information included in the option information is thick paper (S123). If the sheet type is thick paper (S123: YES), the image forming apparatus 1 sets the rotation speed to half speed (S127).

[0064] If the sheet type is not cardboard (S123: NO), the image forming device 1 then determines whether the image forming mode specified by the image forming mode specification information included in the option information is the silent mode (S124). If the image forming mode is the silent mode (S124: YES), the image forming device 1 sets the rotation speed to half speed (S127).

[0065] If the image formation mode is not the silent mode (S124: NO), the image forming device 1 then determines whether the image formation mode specified by the image formation mode specification information included in the option information is the fixing improvement mode (S125). If the image formation mode is the fixing improvement mode (S125: YES), the image forming device 1 sets the rotation speed to half speed (S127).

[0066] If the determination is NO in all of the above steps S122 to S125, image forming apparatus 1 sets the rotation speed to full speed (S126).

[0067] When the sheet S is small size paper, it is necessary to drive the heating roller 105a at half speed in the image forming process S140. When the sheet S is small size paper, the sheet S does not pass the end of the heating roller 105a, so it is necessary to keep the temperature of the heating roller 105a low and to keep the rotation speed of the heating roller 105a low. As described above, if the rotation speed of the heating roller 105a in the preparation process S130 is set to half speed when the sheet S is small size paper, it is possible to match the rotation speed of the heating roller 105a in the preparation process S130 and the image forming process S140.

[0068] Furthermore, if the sheet S is thick paper, it is necessary to drive the heating roller 105a at half speed in the image forming process S140. This is because if the sheet S is thick paper, heat is not easily transferred to the sheet S, and it is therefore necessary to take time to heat the sheet S. As described above, if the rotation speed of the heating roller 105a in the preparation process S130 is set to half speed when the sheet S is thick paper, it is possible to match the rotation speed of the heating roller 105a in the preparation process S130 and the image forming process S140.

[0069] Furthermore, when the image formation mode is the silent mode, the heating roller 105a needs to be driven at half speed in the image formation process S140. This is because when the image formation mode is the silent mode, it is necessary to reduce the motor conveyance noise. As described above, if the rotation speed of the heating roller 105a in the preparation process S130 is set to half speed when the image formation mode is the silent mode, the rotation speed of the heating roller 105a in the preparation process S130 and the image formation process S140 will be the same.

[0070] Furthermore, when the image forming mode is the fixing improvement mode, it is necessary to drive the heating roller 105a at half speed in the image forming process S140. This is because, when the image forming mode is the fixing improvement mode, it is necessary to take time to ensure that the heating roller 105a heats the sheet S. As described above, if the rotation speed of the heating roller 105a in the preparation process S130 is set to half speed when the image forming mode is the fixing improvement mode, it is possible to match the rotation speed of the heating roller 105a in the preparation process S130 and the image forming process S140.

[0071] In the present embodiment, the configuration has been described in which the rotation speed of the heating roller 105a is determined by referring to the image formation mode designation information included in the preceding command as optional information, but the present invention is not limited to this. For example, a configuration may be adopted in which the rotation speed of the heating roller 105a is determined by referring to the image formation mode designation information set using the operation panel 15 and stored in the ROM 12 or RAM 13. In this case, the CPU 111 of the image forming apparatus 1 determines the rotation speed of the heating roller 105a in the rotation speed determination process S120 based on the image formation mode designation information stored in the ROM 12 or RAM 13 of the image forming apparatus 1 in addition to the sheet size designation information and sheet type designation information included in the preceding command as optional information. The CPU 111 of the image forming apparatus 1 may determine the rotation speed of the heating roller 105a based on the image formation mode designation information stored in the ROM 12 or RAM 13 of the image forming apparatus 1 in addition to the sheet size designation information and sheet type designation information included in the preceding command as optional information only when the preceding command does not include the image formation mode designation information as optional information.

[0072] (Example of preparation process) A specific example of the preparation process S130 will be described with reference to Fig. 7. Fig. 7 is a flowchart showing a specific example of the preparation process S130. Note that, unless otherwise specified, the subject of processing in each step described below is the image forming apparatus 1, more specifically, the CPU 111 of the image forming apparatus 1.

[0073] In the preparation process S130, the image forming apparatus 1 starts rotating the heating roller 105a by driving the motor M (S131). At this time, the motor driver 105b that drives the motor M controls the motor M so that the rotation speed of the motor M, i.e., the rotation speed of the heating roller 105a, coincides with the rotation speed determined in the rotation speed determination process S120.

[0074] The image forming apparatus 1 then starts increasing the temperature of the heating roller 105a (S132) using the heater H. The increase in temperature of the heating roller 105a continues, for example, until the temperature of the heating roller 105a reaches a predetermined temperature (S133: YES).

[0075] (PJL analysis and RIP processing) The PJL analysis and RIP processing will now be described. The CPU 111 executes the PJL analysis and RIP processing in parallel with the processing of the flowchart in FIG.

[0076] When the image forming apparatus 1 receives image formation data from the external terminal 2, it executes PJL analysis and RIP processing. Here, PJL analysis refers to processing in which the CPU 111 of the image forming apparatus 1 analyzes the printer job description language included in the image formation data to identify a method for forming an image on a sheet S. Also, RIP processing refers to processing in which the CPU 111 interprets the page description language included in the image formation data to generate raster data representing an image to be formed on a sheet S. The CPU 111 stores the raster data in the page memory 132 of the RAM 13. The raster data is data for each page, and when multiple pages' worth of raster data are included in the image formation data, the CPU 111 ends the processing at the stage where it has completed the PJL analysis and RIP processing for all of the image formation data for the multiple pages.

[0077] (Specific example of image formation process) A specific example of the image forming process S140 will be described with reference to Fig. 8. Fig. 8 is a flowchart showing a specific example of the image forming process S140. Note that, unless otherwise specified, the subject of processing in each step described below is the image forming apparatus 1, more specifically, the CPU 111 of the image forming apparatus 1.

[0078] CPU 111 determines whether there is an image formation queue, that is, whether raster data is stored in page memory 132 (S141). If raster data is stored in page memory 132 (S141: YES), CPU 111 proceeds to S142. If raster data is not stored in page memory 132 (S141: NO), CPU 111 proceeds to S144.

[0079] Image forming apparatus 1 then determines whether or not sheet S can be supplied (S142). If it is determined that sheet S can be supplied (S142: YES), image forming apparatus 1 forms an image represented by the raster data on sheet S (S143). When image formation of an image represented by one page of raster data on sheet S is completed, CPU 111 deletes the raster data for which image formation has been completed from page memory 132. CPU 111 then returns to S141. CPU 111 checks whether raster data is stored in page memory 132 in S141.

[0080] If no raster data is stored in the page memory 132 from the external terminal 2 (S141: NO) and a predetermined time has elapsed (S144: YES), the image forming apparatus 1 ends the image forming process S140 without forming an image on the sheet S. If it is not possible to supply the sheet S (S142: NO) and an error state is detected (S145: YES), the image forming apparatus 1 ends the image forming process S140 without forming an image on the sheet S.

[0081] (Specific example of image formation end process) A specific example of the image formation ending process S150 will be described with reference to Fig. 9. Fig. 9 is a flowchart showing the flow of the image formation ending process S150. Note that, unless otherwise specified, the subject of processing in each step described below is the image forming apparatus 1, more specifically, the CPU 111 of the image forming apparatus 1.

[0082] In the image formation end process S150, the image forming apparatus 1 ends the heating of the heating roller 105a by the heater H that was started in the preparation process S130 (S151). Then, the image forming apparatus 1 stops the rotation of the motor M that drives the heating roller 105a (S152).

[0083] (Example of operation of image forming device) An example of the operation of the image forming apparatus 1 will be described with reference to Fig. 10. Fig. 10 is a timing chart showing an example of the operation of the image forming apparatus 1. Fig. 10 illustrates the process executed by each of the image forming apparatus 1, which is divided into the LAN interface 14, the PJL analysis unit, the RIP processing unit, the engine control unit, the motor driver 105b, and the fixing unit 105. The PJL analysis unit, the RIP processing unit, and the engine control unit are each a functional block realized by the CPU 111.

[0084] In the operation example shown in FIG. 10, the rotation speed of the heating roller 105a in the preparation process S130 is set to half speed according to the preceding command acquired from the external terminal 2. Therefore, when moving from the preparation process S130 to the image formation process S140, it is not necessary to change the rotation speed of the motor M that drives the heating roller 105a. Therefore, it is possible to quickly move from the preparation process S130 to the image formation process S140. In addition, if the rotation speed of the heating roller 105a in the image formation process S140 is half speed, the rotation speed of the heating roller 105a in the preparation process S130 is also half speed, so that it is possible to keep the level of noise generated by the image forming apparatus 1 low before starting the image formation process S140.

[0085] (Variation 1) In the present embodiment, the preceding command transmitted from the external terminal 2 includes sheet size designation information, sheet type designation information, and image formation mode designation information as optional information, and the image forming apparatus 1 determines the rotation speed of the heating roller 105a based on this information. However, the present invention is not limited to this. That is, the external terminal 2 may determine the rotation speed of the heating roller 105a based on the sheet size, sheet type, and image formation mode, and transmit a preceding command to the image forming apparatus 1 including rotation speed designation information for designating the determined rotation speed as optional information. In this case, the external terminal 2 executes a process similar to the rotation speed determination process S120. The image forming apparatus 1 determines the rotation speed of the heating roller 105a based on the rotation speed designation information included as optional information in the preceding command.

[0086] (Variation 2) In the present embodiment, a configuration has been described in which the image forming apparatus 1 always executes the preparation process S130, but the present invention is not limited to this. That is, a configuration may be adopted in which the preparation process S130 is executed when the rotation speed determined in the rotation speed determination process S120 is full speed, and the preparation process S130 is omitted when the rotation speed determined in the rotation speed determination process S120 is half speed.

[0087] FIG. 11 is a flowchart showing the flow of operations of the image forming apparatus 1 in this case. The flowchart shown in FIG. 11 is the flowchart shown in FIG. 5 to which step S160 for determining whether the rotation speed is half speed or not has been added. The preparation process S130 is executed only when the rotation speed determined in the rotation speed determination process S120 is not half speed, for example, when it is full speed (S160: NO). This is because do not have In this case, the preparation process S130 is executed immediately after the rotation speed determination process S120 is completed, whereas the rotation speed determined in the rotation speed determination process S120 is half speed. beIn this case, it means that the preparation process S130 is not executed immediately after the completion of the rotation speed determination process S120. When the rotation speed determined in the rotation speed determination process S120 is half speed, for example, after receiving image formation data, a process equivalent to the preparation process S130 is executed, and then a process equivalent to the image formation process S140 is executed.

[0088] If the preparation process S130 is not performed when the rotation speed is half speed, the preparation process is performed after receiving image formation data, and the image formation process is then executed, so that the motor rotation speed is not switched. Therefore, no time is lost for switching the motor rotation speed. This makes it possible to quickly transition to the image formation process. In addition, when the rotation speed of the heating roller 105a in the image formation process is half speed, the preparation process S130 is omitted, so that it is possible to prevent the image forming apparatus 1 from making noise before starting the image formation process.

[0089] (Example of software implementation) The control block of the image forming apparatus 1 may be realized by a logic circuit (hardware) formed in an integrated circuit (IC chip) or the like, or may be realized by software.

[0090] In the latter case, the image forming apparatus 1 includes a computer that executes instructions of a program, which is software that realizes each function. The computer includes, for example, one or more processors, and a computer-readable storage medium that stores the program. The processor in the computer reads the program from the storage medium and executes it, thereby achieving the object of the present invention. The processor may be, for example, a CPU. The storage medium may be a "non-transient tangible medium," such as a ROM, tape, disk, card, semiconductor memory, programmable logic circuit, or the like. The image forming apparatus 1 may further include a RAM for expanding the program. The program may be supplied to the computer via any transmission medium (such as a communication network or broadcast waves) that can transmit the program. Note that one aspect of the present invention may also be realized in the form of a data signal embedded in a carrier wave, in which the program is embodied by electronic transmission.

[0091] (Additional Notes) The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention. [Explanation of symbols]

[0092] 1. Image forming device 10 Image forming section 11 ASIC 12 ROM 13 RAM 14 LAN Interface 15 Operation Panel

Claims

1. an image forming unit that forms an image on a sheet in accordance with image formation data transmitted from an external terminal, the image forming unit having a roller that conveys a sheet and a drive unit that applies a driving force to the roller to rotate the roller at a predetermined speed; A control unit, The control unit is an acquisition process for acquiring a preceding command transmitted from the external terminal prior to the image formation data; a determination process for determining a rotation speed of the roller to be a first speed or a second speed based on option information included in the preceding command; a preparation process for controlling the driving unit to rotate the roller at the rotation speed determined in the determination process before the image forming unit starts image formation; Run the image forming unit has a fixing unit that thermally fixes the toner image onto a sheet; The control unit is when the rotation speed determined in the determination process is the first speed, the preparation process is executed before the image formation data is received, and when the rotation speed determined in the determination process is the second speed which is slower than the first speed, the preparation process is not executed until the image formation data is received.

1. An image forming apparatus comprising:

2. The control unit is When the rotation speed determined in the determination process is a first speed, the driving unit is controlled in the preparation process so that the roller rotates at the first speed, and when the rotation speed determined in the determination process is a second speed different from the first speed, the driving unit is controlled in the preparation process so that the roller rotates at the second speed.

2. The image forming apparatus according to claim 1,

3. the option information includes designation information for designating at least one of a sheet size, a sheet type, and an image forming mode; In the determination process, the control unit determines the rotation speed of the roller based on the designation information.

3. The image forming apparatus according to claim 1, wherein the first and second electrodes are arranged in a first direction.

4. In the determination process, the control unit determines the rotation speed of the roller based on internal designation information that is stored in the image forming apparatus and that designates the image forming mode, in addition to the designation information included in the option information.

4. The image forming apparatus according to claim 3.

5. An image forming unit that forms an image on a sheet in accordance with image formation data transmitted from an external terminal, the image forming unit having a roller that transports the sheet and a drive unit that applies a driving force to the roller to rotate the roller at a predetermined speed; A control unit, The control unit is an acquisition process for acquiring a preceding command transmitted from the external terminal prior to the image formation data; a determination process for determining a rotation speed of the roller to be a first speed or a second speed based on option information included in the preceding command; a preparation process for controlling the driving unit to rotate the roller at the rotation speed determined in the determination process before the image forming unit starts image formation; Run the option information includes designation information for designating at least one of a sheet size, a sheet type, and an image forming mode; In the determination process, the control unit determines the rotation speed of the roller based on the designation information, and determines the rotation speed of the roller based on internal designation information that is stored in the image forming apparatus and that designates the image formation mode in addition to the designation information included in the option information.

1. An image forming apparatus comprising:

6. In the determination process, when the option information does not include designation information for designating the image formation mode, the control unit determines the rotation speed of the roller based on the designation information stored in the image forming device, which designates the image formation mode, in addition to the designation information included in the option information.

6. The image forming apparatus according to claim 5,

7. An image forming unit that forms an image on a sheet in accordance with image formation data transmitted from an external terminal, the image forming unit having a roller that transports the sheet and a drive unit that applies a driving force to the roller to rotate the roller at a predetermined speed; A control unit, The control unit is an acquisition process for acquiring a preceding command transmitted from the external terminal prior to the image formation data; a determination process for determining a rotation speed of the roller to be a first speed or a second speed based on option information included in the preceding command; a preparation process for controlling the driving unit to rotate the roller at the rotation speed determined in the determination process before the image forming unit starts image formation; Run the option information includes designation information for designating whether the rotation speed of the roller is to be the first speed or the second speed different from the first speed, In the determination process, the control unit determines whether the rotation speed of the roller is to be the first speed or the second speed in accordance with the designation information.

1. An image forming apparatus comprising:

8. the image forming unit includes a heater and a heating roller heated by the heater, The roller is a heating roller.

8. The image forming apparatus according to claim 7, wherein the image forming apparatus comprises:

9. An acquisition process for acquiring a preceding command transmitted from an external terminal prior to the image formation data; a determination process for determining a rotation speed of a roller of an image forming unit to be a first speed or a second speed based on option information included in the preceding command; a preparation process for rotating the roller before the image forming unit starts image formation; an image forming process of forming an image on a sheet according to the image forming data by using the image forming unit, controlling a drive unit that drives the roller in the preparation process so that the roller rotates at the rotation speed determined in the determination process; the image forming unit has a fixing unit that thermally fixes the toner image onto a sheet; when the rotation speed determined in the determination process is the first speed, the preparation process is executed before the image formation data is received, and when the rotation speed determined in the determination process is the second speed which is slower than the first speed, the preparation process is not executed until the image formation data is received.

1. An image forming method comprising:

Images