JP4577347B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus, and more particularly to an image forming apparatus that thermally fixes a toner image on a print medium.

  An image forming apparatus such as an MFP (Multi Function Peripheral) that is a printer, a copier, a facsimile machine, or a device that combines these functions, and prints by fixing a toner image on a sheet of printing medium by heating. In an image forming apparatus, from the viewpoint of energy saving or the like, normally, after the printing operation is finished, the heating of the fixing unit with the heater is released for a predetermined time, and the temperature of the fixing unit is changed from a high temperature state that is the printing temperature to a low temperature that is the standby temperature. The temperature control is performed so as to wait for the next print request to be made. When a print request is made after the standby temperature has been shifted, the image forming apparatus further heats the fixing unit with a heater, and starts the printing operation so that the fixing unit reaches the printing temperature before the paper reaches the fixing unit. Is controlled to adjust.

  When the temperature of the image forming apparatus is controlled as described above, the fixing unit may not be an appropriate temperature for printing when a printing request is made near the switching timing from the printing temperature to the standby temperature. There was a problem that may cause. In order to solve this problem, for example, Japanese Patent Application Laid-Open No. 11-344892 (hereinafter referred to as Patent Document 1) freezes a print command once when a print command is received in the vicinity of the temperature switching timing, and enters a stable control mode. A technique of waiting for a print command until the entry timing is disclosed.

Further, since the start of the printing operation is adjusted as described above, there is also a problem that the start of the printing operation is delayed when a printing request is made after the printing is completed. For this reason, a method has been proposed in which a printing operation is started as soon as possible when a printing request is made after printing. The method includes, for example, a method in which the polygon motor is continuously rotated for a predetermined time after the printing is completed, and a third temperature control between the printing temperature and the standby temperature. The method of controlling to become temperature etc. are mentioned.
Japanese Patent Laid-Open No. 11-344892

  However, the technique of waiting for a print command until the timing of entering a stable control mode as disclosed in Patent Document 1 still has a problem that the start of a print operation is delayed when a print request is made after the end of printing. .

  In order to solve this problem, there has been proposed a method in which the polygon motor is continuously rotated for a predetermined time after the printing is completed, but even when this method is employed, the printing operation is not started until the printing operation is started. When the time is determined by the temperature of the fixing unit as in the prior art, there is still a problem that the start of the printing operation is delayed until the fixing unit reaches the printing temperature.

  Further, when the method of controlling the temperature to be the third temperature for a predetermined time after the printing is completed, there is a problem that the temperature control of the fixing unit is complicated. There is also a problem of increased energy consumption.

  The present invention has been made in view of these problems, and is an image forming apparatus that thermally fixes a toner image on a printing medium, and does not complicate temperature control and saves energy while printing. It is an object of the present invention to provide an image forming apparatus capable of shortening the time from a printing request after completion to the start of the next printing operation.

In order to achieve the above object, according to one aspect of the present invention, an image forming apparatus is suitable for heat fixing a toner image on a print medium and a fixing means for fixing the toner image on the print medium. Temperature control means for adjusting the temperature to a first temperature that is lower than the first temperature and a second temperature that is lower than the first temperature and lower than the heat-fixable temperature, and a print request that accepts the print request Means, a print control means for controlling a print operation executed in response to the print request, a delay control means for performing a process for delaying the start of the print operation, and immediately before the current print request received by the print request means timing means for switching control to switch the temperature of the fixing means from the first temperature in the temperature control means with the termination of the printing operation in accordance with the print request to a second temperature to measure an elapsed time from being made, just before Included in the print request Compares the first setting means for setting a first reference time based on the attributes of the medium, the elapsed time and the first reference time from the switching control which is measured by the time measuring means to the current print request is made, When the current print request is made after the first reference time has elapsed from the switching control, the delay control means performs delay processing, and when the print request is made before the first reference time has elapsed from the switching control. Includes a control unit that causes the print control unit to start a printing operation without performing delay processing in the delay control unit, and the attribute of the print medium is an attribute related to the heat absorption of the fixing unit, and is a first setting. means to set the first reference time shorter than when the attribute of the print medium contained in the immediately preceding print request small when a large amount of heat absorbed from the fixing means.

More preferably, the first setting means includes a storage means for storing a correspondence relationship between the print medium attribute and the first reference time, an acquisition means for obtaining the print medium attribute from the print request, and at least a previous print request. Storage means for storing the acquired attribute of the print medium, and reading means for reading out the first reference time from the correspondence relationship based on the attribute of the print medium acquired from the immediately preceding print request .

More preferably, the attribute of the print medium includes at least one of a length conveyed in contact with the fixing unit of the print medium and a thickness of the print medium, and the first reference set by the first setting unit. The time is shorter when the length of the print medium conveyed in contact with the fixing means is longer than when the print medium is long, and shorter when the length of the print medium is thick than when it is thin.

Preferably, the first setting means further sets a first reference time based on the conveying speed of the print medium in the print operation is executed according to this print request, the first setting means, slow transport speed sometimes length rather than to set the first reference time than when fast.

Preferably, the first setting means includes a storage means for storing a correspondence relationship between the attribute of the print medium that affects the conveyance speed and the first reference time, an acquisition means for acquiring the attribute of the print medium from the print request, and a print Reading means for reading the first reference time from the correspondence based on the attribute of the medium.

More preferably, the attribute of the print medium includes the thickness of the print medium, and the first reference time set by the first setting unit is longer when the print medium is thin than when the print medium is thin.

Preferably, the image forming apparatus compares the elapsed time from when the first reference time elapses until the current print request is made with the second reference time, which is measured by the timing unit, to the current reference time . A delay time for delaying the start of the current printing operation by the delay control means is set as the second reference time when the print request is made after the first reference time has elapsed from the switching control and after the second reference time has elapsed; If the current print request is made before the second reference time elapses after the first reference time elapses from the switching control, the current print request is made after the first reference time elapses from the switch control. And a second setting means for setting the elapsed time until the first time.

  Preferably, the image forming apparatus further includes a temperature measuring unit that measures the temperature of the fixing unit in a non-contact manner.

  In the image forming apparatus according to the present invention, compared to the conventional method of starting the printing operation after heating the fixing unit from the standby temperature to the printing temperature after receiving the printing request when the printing request is made after the printing is finished, If the elapsed time from the end of printing to the next print request is within the specified time, complicated control is not required, and the time from the print request to the start of printing operation is shortened while saving energy can do.

  Embodiments of the present invention will be described below with reference to the drawings. In the following description, the same parts and components are denoted by the same reference numerals. Their names and functions are also the same.

  The image forming apparatus according to the present invention is an image forming apparatus that thermally fixes a toner image on a print medium, and includes a printer, a copying machine, a facsimile, and a multifunction device (MFP) that is a combination of these functions. To do. In this embodiment, it is assumed that the image forming apparatus is a tandem color printer (hereinafter abbreviated as a printer).

  FIG. 1 is a schematic diagram illustrating a specific example of a cross section of a central portion of a printer 1 according to the present embodiment.

  Referring to FIG. 1, a printer 1 according to the present embodiment is mainly configured to include an image forming unit and a paper conveyance unit that is a printing medium.

  The image forming unit includes an annular intermediate transfer belt 2 that is an intermediate transfer member and is suspended from the inside by a plurality of rollers, which is disposed at a substantially central portion inside the printer 1. The intermediate transfer belt 2 is connected to the main motor 18 and is rotated by the rotation of the main motor 18. Along the intermediate transfer belt 2, cartridges 28a, 28b, 28c, and 28d corresponding to the respective colors of yellow (Y), magenta (M), cyan (C), and black (K) are arranged. In each of the cartridges 28a, 28b, 28c, and 28d, photoconductors 3a, 3b, 3c, and 3d that transfer the toner image onto the intermediate transfer belt 2 are provided as toner image forming means for forming a toner image by electrostatic recording. Charging portions 5a, 5b, 5c, and 5d for uniformly charging the surface of the photoconductor, and exposure portions 6a, 6b, 6c, and 6d for sequentially forming image patterns of respective colors on the photoconductor by exposure. And developing units 4a, 4b, 4c, and 4d for supplying toner to the photoconductor and developing the toner image on the photoconductor. Of the cartridges 28a, 28b, 28c, and 28d, the developing mechanism for the color cartridge is connected to the color developing motor 20, and the developing mechanism for the monochrome cartridge is connected to the developing motor 21, and each is rotationally driven.

  Further, the image forming unit accommodates the intermediate transfer belt cleaner 7 disposed around the intermediate transfer belt 2 and separating the residual toner remaining on the intermediate transfer belt 2 from the intermediate transfer belt 2 and the separated residual toner. Waste toner box 15 and toner bottles 25a, 25b, 25c, and 25d for supplying toner to cartridges 28a, 28b, 28c, and 28d by operating by incorporating stirring blades 26a, 26b, 26c, and 26d, respectively. included. The toner bottles 25a and 25b are connected to the toner supply motor 23, and the toner bottles 25c and 25d are connected to the toner supply motor 24, and the stirring blades 26a, 26b, 26c and 26d are operated by the rotation of the motor.

  Further, in the image forming unit, a toner image transferred onto the intermediate transfer belt 2 that forms a pair with the intermediate transfer belt 2 sandwiched between the roller that suspends the intermediate transfer belt 2 from the inside is transferred onto the conveyed paper. The secondary transfer roller 11 is included.

  The transport unit includes a paper feed roller 8 that feeds paper from a storage unit 16 that is a cassette for storing paper, and a timing roller 10 that temporarily stops the fed paper. The secondary transfer roller 11 described above, the neutralizing cloth 30 for neutralizing the paper, and a fixing unit that is arranged with the conveyed paper sandwiched between and heats and fixes the toner image transferred onto the paper. There is a timing via a pair of fixing rollers 12a and 12b (representing them as the fixing roller 12), a discharge roller 13 for discharging the fixed sheet or conveying it to the duplex conveying path 29, and the duplex conveying path 29. Double-sided path conveying rollers 14 a and 14 b that convey the sheet to the roller 10 are included. The paper feed roller 8, the timing roller 10, and the secondary transfer roller 11 are connected to the main motor 18 and are rotated by the rotational drive of the main motor 18. The fixing roller 12 is connected to the fixing motor 19 and is rotated by the rotation driving of the fixing motor 19. The double-side path transport rollers 14 a and 14 b are connected to the double-side path transport motor 22 and are rotated by the rotational drive of the double-side path transport motor 22.

  In addition, a paper detection sensor 32 is disposed immediately before the paper reaches the timing roller 10 in the conveyance path, and detects that the leading edge of the paper has passed and / or the trailing edge of the paper has passed.

  A thermistor 31 is disposed in the vicinity of the fixing roller 12 as means for measuring the temperature of the fixing roller 12 as fixing means. The thermistor 31 is a non-contact type temperature measuring means, and is disposed at a position away from the fixing roller 12 by a predetermined distance and measures the temperature of the surface. It is assumed that the positional relationship between the fixing roller 12 and the thermistor 31 is a positional relationship as shown in FIG. 2A as a specific example. Specifically, the thermistor 31 is arranged at a position away from the fixing roller 12 by a predetermined distance and measures the surface temperature. The structure of the thermistor 31 is not limited in this invention, A commercially available thing can be used. FIG. 2B shows a specific example of a simple circuit configuration of the thermistor 31. For example, as a specific example of a commercially available thermistor, a non-contact thermistor (9 type element) manufactured by Shibaura Electronics Co., Ltd. is used, and the distance from the fixing roller 12 is 2.3 ± 0.3 mm, and the detection resistance at that time Can be 33 kΩ ± 1%.

  Further, the printer 1 includes an engine unit 100 that includes a CPU (Central Processing Unit) and controls the whole, and a controller unit 200 that performs image processing in accordance with a control signal from the engine unit 100. The engine unit 100 receives a print request input from an operation panel (not shown), a signal designating a paper size and type, and the like. The engine unit 100 is connected to the paper detection sensor 32 and receives a detection signal from the paper detection sensor 32. Based on these, engine unit 100 generates a control signal for controlling each unit.

  The motors 18 to 24 are connected to the engine unit 100 and stop rotating or rotating according to a control signal from the engine unit 100. The engine unit 100 determines the sheet conveyance timing based on the detection signal, and outputs a control signal for rotating or stopping the rotation of the motor to which each roller included in the conveyance unit is coupled. Accordingly, the operation of each unit of the printer 1 is controlled by the engine unit 100.

  The engine unit 100 and the controller unit 200 are connected to each other, and the controller unit 200 is supplied with a print request and information specifying the paper size and type, and outputs a control signal for performing image processing. The engine unit 100 acquires a digital image signal as an image processing result from the controller unit 200, and outputs a control signal to the exposure units 6a, 6b, 6c, and 6d based on the digital image signal. The exposure units 6a, 6b, 6c and 6d irradiate laser light according to the control signal. As a result, an electrostatic latent image is formed for each color on the surface of the photoreceptors 3a, 3b, 3c, and 3d.

  FIG. 3 is a block diagram illustrating a specific example of the configuration of the engine unit 100 and the controller unit 200.

  Referring to FIG. 3, the engine unit 100 includes a control unit 101 for controlling the entire printer 1, a unit-attached nonvolatile memory 102 that is a storage device mounted on the engine unit 100, and a printer (not shown). 1 includes a non-volatile memory 103 attached to the main body for accessing a storage device mounted on 1 and an output unit 104 for outputting a control signal to various loads such as the motor connected to the engine unit 100. It is. The controller unit 200 includes an image processing unit 201 that performs image processing in accordance with a control signal from the engine unit 100.

  The configuration included in the engine unit 100 may be formed in the CPU by reading and executing a program stored in the nonvolatile memory 102 or the nonvolatile memory 103 by a CPU (not shown). Further, in this specific example, as shown in FIG. 3, the engine unit 100 and the controller unit 200 each include the above-described configuration. However, the engine unit 100 and the controller unit 200 have one A configuration may be used, and a combination of configurations included in each of the engine unit 100 and the controller unit 200 is not necessarily the combination shown in FIG. 3.

[First Embodiment]
FIG. 4 is a block diagram illustrating a specific example of a functional configuration of the printer 1 for controlling the start of the printing operation according to the first embodiment. The functions shown in FIG. 4 are mainly performed by a CPU mounted on the control unit 101 included in the engine unit 100 by reading and executing a program stored in the nonvolatile memory 102 or the nonvolatile memory 103. It may be formed.

  Referring to FIG. 4, the above function of printer 1 is a temperature adjustment control unit 301 that performs control for adjusting the temperature of fixing roller 12 as a fixing unit from a printing temperature to a standby temperature or from a standby temperature to a printing temperature. A print request unit 303 that receives a print request input from an operation panel (not shown), and a time measuring unit 307 that measures an elapsed time from the timing when the temperature control unit 301 switches the temperature from the print temperature to the standby temperature. A response time setting unit 309 that sets a response time T1, which is a time that can correspond to the start of the printing operation without performing delay control, a response time storage unit 311 that stores the above response time, and a print request are made. A determination unit 313 for determining whether to perform a delay control or a delay control to start a printing operation, a delay control unit 315 to perform a delay control, and a printing operation Configured to include a print control unit 317 for controlling.

  As described above, the temperature control unit 301 performs the printing operation in response to the print request based on the detection signal from the paper detection sensor 32 from the viewpoint of energy saving, and the last paper is the fixing roller. When it is detected that the toner has passed through 12, the output unit 104 outputs a control signal for turning off a heater (not shown) for heating the fixing roller 12 for a predetermined time, and switches the temperature of the fixing unit from the printing temperature to the standby temperature. For temperature control. Specifically, the temperature at which the surface temperature of the fixing roller 12 is 200 ° C. corresponds to the printing temperature. Further, the standby temperature specifically corresponds to a temperature at which the surface temperature of the fixing roller 12 is 180 ° C. Further, the temperature control unit 301 is connected to the print request unit 303, and when the print request unit 303 detects that the print request has been received, the output unit 104 increases the heating amount of the heater (not shown). The control signal is output to control the temperature of the fixing roller 12 from the standby temperature to the printing temperature.

  The timer unit 307 is connected to the temperature control unit 301, and when the temperature control unit 301 detects that the temperature control for switching the fixing unit from the printing temperature to the standby temperature is performed, the elapsed time from the timing is detected. measure.

  The print request unit 303 is connected to an operation panel (not shown) and receives a print request that is an operation signal input by operating the operation panel. Alternatively, when the printer 1 includes a communication unit and communicates with another apparatus such as a personal computer, the print request may be transmitted from another apparatus.

  The corresponding time storage unit 311 is constituted by, for example, the nonvolatile memory 102 and stores a corresponding time T1 set in advance. The response time T1 is from when the temperature control for switching the fixing unit from the printing temperature to the standby temperature is performed by the temperature control unit 301 until the temperature of the fixing unit gradually decreases from the printing temperature and reaches the standby temperature. It shall be determined based on time. The response time setting unit 309 is connected to the response time storage unit 311 and reads and sets the response time T1 from the response time storage unit 311.

  The determination unit 313 is connected to the print request unit 303, the time measuring unit 307, and the corresponding time setting unit 309, and is measured by the time measuring unit 307. The temperature control is switched from the print temperature in the temperature control unit 301 to the standby temperature. The elapsed time T2 from the timing when the print request is made to the time when the print request is made is compared with the corresponding time T1 set by the corresponding time setting unit 309, and delay control is performed on the delay control unit 315 according to the result. An instruction signal for performing the printing operation or an instruction signal for starting the printing operation to the printing control unit 317 is output.

  The delay control unit 315 is connected to the print control unit 317 and controls to delay the start of the printing operation by the print control unit 317 for a predetermined time. In the present invention, the specific contents of the delay processing are not limited to specific processing, and may be processing generally performed in the image forming apparatus. The delay time T3, which is the predetermined time, is determined based on the time required for the temperature of the fixing unit to rise to the printing temperature. For example, a time of 5 s is stored in advance. In order to increase the temperature of the fixing unit to a temperature at which printing can be performed before the paper reaches the fixing unit after the printing request is made, the delay control unit 315 controls to delay the start of the printing operation by the delay time T3. To do. The print control unit 317 outputs a control signal to the image processing unit 201 at a timing when an instruction signal is input from the determination unit 313 or according to a control signal from the delay control unit 315. Is started, and control for causing the printing process to be performed is performed. Here, the “printable temperature” of the fixing unit indicates a temperature higher than the above-described “standby temperature”. That is, the temperature from the “printing temperature” to the “standby temperature” described above corresponds to the “printable temperature”.

  FIG. 5 is a flowchart illustrating a specific example of processing according to the first embodiment executed by the printer 1. The CPU shown in the control unit 101 included in the engine unit 100 reads and executes the program stored in the non-volatile memory 102 or the non-volatile memory 103 in the process shown in the flowchart of FIG. This is realized by controlling each unit shown in FIG.

  Referring to FIG. 5, first, when temperature control for switching the temperature of fixing roller 12 from the printing temperature to the standby temperature is performed in temperature control unit 301 (YES in step S101), time measuring unit 307 Measurement of the elapsed time is started (step S103). When the print request unit 303 receives a print request from an operation panel (not shown) or the like (YES in step S105), the corresponding time setting unit 309 reads and sets the corresponding time T1 stored in the corresponding time storage unit 311 ( Step S107). Further, an elapsed time T2 measured by the time measuring unit 307 from the start of the measurement in step S103 until the time when the print request is made in step S105 is acquired (step S109). In the process according to the first embodiment, the timing at which the process of step S107 is executed is not limited to this timing, and may be any time before this timing.

  The determination unit 313 compares these times T1 and T2 (step S111), and if the elapsed time T2 is greater than the corresponding time T1, in other words, the print request in step S105 is subjected to temperature control in step S101. If the processing is not performed after the response time T1 set in step S107 has elapsed but after that (YES in step S111), a delay process is executed in the delay control unit 315 (step S111). After that, that is, after a predetermined delay time T3, the print control unit 317 performs a printing operation (step S115).

  On the other hand, if the elapsed time T2 is shorter than the corresponding time T1, in other words, the printing request in step S105 is performed until the corresponding time T1 set in step S107 elapses after the temperature control in step S101 is performed. If this is done (NO in step S111), the delay process in the delay control unit 315 is not executed, step S113 is skipped, and the printing operation is performed in the print control unit 317 (step S115). That is, in this case, when a printing request is made in step S105, the printing operation in step S115 is immediately started without passing through the delay time T3.

  The operation timing in the printer 1 in which the processing according to the first embodiment shown in FIG. 5 is performed will be described with reference to FIGS. FIG. 6A shows the operation timing in the case where the print request is not made within the corresponding time T1 after the temperature adjustment control for switching to the standby temperature is performed, and thereafter. FIG. 6B shows the operation timing when a print request is made within the corresponding time T1 after the temperature control is performed. Here, it is assumed that 20 s is set as the corresponding time T1 in step S107. In addition, the delay time T3 in the delay control unit 315 is set to 5 s in advance. In the example of FIGS. 6A and 6B, for the sake of convenience, it is assumed that the same print request is made, and the time T4 from when the printing operation starts until the paper reaches the fixing unit is 10 s. .

  Referring to FIG. 6A, it is assumed that the set corresponding time T1 has elapsed from the time Ta at which the temperature control is performed (time (Ta + T1)), and a printing request is made at time Tb thereafter. . In this case, the temperature of the fixing unit gradually decreases from the printing temperature from the Ta point, and reaches the standby temperature when the corresponding time T1 has elapsed (Ta + T1). Therefore, when a print request is made at time Tb, first, the temperature adjustment control unit 301 performs control for raising the temperature of the fixing unit from the standby temperature to the print temperature. Then, the delay process in step S113 is performed in order to delay the time for the sheet conveyed according to the print request to reach the fixing unit by a delay time T3 corresponding to the time required for the temperature rise of the fixing unit. At time (Tb + T3) after the lapse of time T3, the printing operation in step S115 is started.

  Referring to FIG. 6B, it is assumed that a print request is made at a time Tc before the set corresponding time T1 elapses from a time Ta at which the temperature control is performed. In this case, although the temperature of the fixing unit gradually decreases from the printing temperature from the Ta point, it does not reach the standby temperature at the Tc point before the (Ta + T1) point, and is a printable temperature. For this reason, when a print request is made at time Tc, the temperature adjustment control unit 301 performs control for raising the temperature of the fixing unit from the standby temperature to the print temperature. The printing operation in step S115 is started immediately without performing the delay process in S113.

  The timing of the printing operation shown in FIG. 6A is the same as the timing of the printing operation with delay processing in the conventional image forming apparatus. In the specific example shown in FIG. 6A, it takes a delay time T3 (= 5 s) and a time T4 (= 10 s) from when the printing request in step S105 is made until the sheet reaches the fixing unit. It will be. On the other hand, when the printer 1 executes the process according to the first embodiment and a print request is made within the set corresponding time, in the specific example shown in FIG. The time required from the time when the printing request is made in step S105 until the paper reaches the fixing means is only the time T4 (= 10 s) required for the printing operation.

  As is apparent from a comparison between FIG. 6A and FIG. 6B, the processing according to the first embodiment described above is executed in the printer 1, so that the temperature of the fixing unit is set to the standby temperature. When a print request is made within a predetermined time from when the temperature control to be switched to is performed until the standby temperature control is reached, the print operation is started as soon as the print request is made. Therefore, it is possible to shorten the time from the printing request to the start of the printing operation while saving energy and without requiring complicated control.

[Second Embodiment]
In the first embodiment, the temperature of the fixing unit gradually decreases from the printing temperature after the temperature control for switching the fixing unit from the printing temperature to the standby temperature is performed by the temperature control unit 301 in the first embodiment. Thus, it is set in advance based on the time until the standby temperature is reached. Here, the sheet is transported while being thermally fixed by the fixing rollers 12a and 12b between the pair of fixing rollers 12a and 12b, and the sheet absorbs the amount of heat, and the temperature of the fixing unit is transported. Decreases depending on paper. The amount of heat absorbed by the paper increases as the contact time with the fixing roller 12 increases and as the heat capacity of the paper increases. That is, the longer the paper size (length) in the transport direction, the lower the temperature of the fixing unit. Also, the thicker the paper, the lower the temperature of the fixing means. Therefore, the temperature of the fixing unit is influenced by the attribute of the paper according to the previous printing request, and as a result, the time until the temperature of the fixing unit gradually decreases from the printing temperature and reaches the standby temperature by the temperature control. Also, it is affected by the paper attributes according to the previous print request. Therefore, in the second embodiment, it is assumed that processing is performed in consideration of the attribute of the paper according to the previous print request.

  FIG. 7 is a block diagram illustrating a specific example of a functional configuration of the printer 1 for controlling the start of the printing operation according to the second embodiment. The function shown in FIG. 7 further includes an attribute acquisition unit 305 that acquires the attribute of the paper to be printed included in the print request and an attribute storage unit 306 that stores the attribute in addition to the function shown in FIG. Composed.

  The print request includes information for specifying image data to be printed, information for specifying attributes such as the size and thickness of paper to be printed, and information for specifying the number of prints. The attribute acquisition unit 305 acquires attributes such as the paper size and thickness from the print request, and passes the information to the corresponding time setting unit 309. Further, the information indicating the acquired attribute is stored in the attribute storage unit 306 together with information for specifying the printing time (for example, the printing time, the time when the print request is received, etc.). Alternatively, the attribute storage unit 306 may store only information indicating the attribute of the paper included in the previous print request. In this case, the information indicating the attribute acquired from the print request by the attribute acquisition unit 305 is the attribute. It is assumed that the storage unit 306 is overwritten and stored.

  In the second embodiment, the corresponding time storage unit 311 stores the correspondence between the attribute of the paper and the corresponding time according to the previous print request, as shown in FIG. Here, specifically, it is assumed that the correspondence between the paper size and paper thickness and the corresponding time is stored as the paper attribute. As described above, the temperature decrease of the fixing unit increases as the paper size increases. Also, the thicker the paper, the greater the temperature drop of the fixing means. Therefore, when the above temperature control is performed by the temperature control unit 301, the fixing means is larger as the paper size is larger and the paper is thicker than when the paper size is small and when the paper is thin. The temperature is lower. Therefore, in the second embodiment, as shown in FIG. 8, the corresponding time is set shorter as the paper size is larger and shorter as the paper is thicker.

  The processing according to the second embodiment executed by the printer 1 is the same as the processing shown in the flowchart of FIG. However, in the processing according to the second embodiment, the corresponding time T1 corresponding to the attribute of the paper included in the previous print request stored in the attribute storage unit 306 is obtained from the corresponding time storage unit 311 in step S107. Read and set.

  The operation timing in the printer 1 in which the processing according to the second embodiment is performed will be described with reference to FIGS. 9 (A), (B) and FIGS. 10 (A), (B). FIGS. 9A and 9B show the operation timing when the paper according to the previous print request is A4 size and thick paper. 10A and 10B show operation timings when the paper according to the previous print request is legal size and plain paper. Specifically, FIG. 9A and FIG. 10A show operation timings when the print request is not made within the corresponding time T1 after the temperature adjustment control to switch to the standby temperature is performed, and thereafter. . FIGS. 9B and 10B show operation timings when a print request is made within the corresponding time T1 after the temperature control is performed.

  Referring to FIGS. 9A and 9B, when the paper according to the previous print request is A4 size and thick paper, in step S107, the correspondence time T1 is set to 15 seconds from the correspondence shown in FIG. Is set. Thereafter, the printing operation is started at the same timing as that described with reference to FIGS. 6A and 6B (except for the specific corresponding time T1). Similarly, referring to FIGS. 10A and 10B, when the paper according to the previous print request is legal size and plain paper, in step S107, the correspondence is shown in FIG. 18s is set as the time T1. Thereafter, the printing operation is started at the same timing as that described with reference to FIGS. 6A and 6B (except for the specific corresponding time T1). Therefore, by comparing FIG. 9A and FIG. 9B, and by comparing FIG. 10A and FIG. 10B, FIG. 6A and FIG. As described above, when a print request is made within the set corresponding time T1, the print operation is started immediately after the print request is made, and the time from the print request to the start of the print operation is shortened. be able to.

  Further, by comparing FIG. 6 (A), (B) with FIG. 9 (A), (B), FIG. 6 (A), (B) and FIG. 10 (A), (B) are also compared. As is apparent from the comparison, in the second embodiment, the corresponding time T1 is set in the printer 1 according to the attribute of the paper according to the previous print request. That is, as shown in FIGS. 6A and 6B, when the attribute of the paper according to the previous print request is an attribute with small heat absorption (small size paper, thin paper), The corresponding time T1 is set longer than in the case of the large heat absorption attribute (large size paper, thick paper) shown in FIGS. 9 (A), (B) and FIGS. 10 (A), (B). The Therefore, in many cases, delay processing can be made unnecessary as compared with the case where the corresponding time T1 is set regardless of the attribute of the paper according to the previous print request as in the first embodiment. . Thereby, the time from the printing request to the start of the printing operation can be shortened.

  In the second embodiment, the corresponding time T1 is determined according to the size and thickness of the paper as the paper attribute according to the previous print request, but the temperature of the fixing means is the same as that of the fixing roller 12. Since the longer the contact time with the sheet to be printed, the longer the contact time, more precisely, the corresponding time may be determined according to the sheet length in the transport direction. When the storage unit 16 includes a plurality of cassettes and the print request includes information specifying the cassette to be fed, the attribute acquisition unit 305 specifies information specifying the cassette in addition to the paper size from the print request. It is also preferable to obtain the sheet length in the sheet conveyance direction. In this way, even when the paper size is the same, the corresponding time can be set according to the paper length in the transport direction, and in many cases, the delay processing can be made unnecessary.

[Third Embodiment]
As described above, if a print request is made when the temperature of the fixing unit is the standby temperature, the temperature of the fixing unit is printed at least within the time from when the print request is made until the paper reaches the fixing unit. It needs to be raised to a possible temperature. Since the temperature of the fixing unit may not reach the printable temperature when the paper reaches the fixing unit, a delay process is performed to ensure the time until the temperature of the fixing unit reaches the printable temperature. The printing operation is started after the delay time has elapsed since the printing request was made.

  When the time from the start of the printing operation until the sheet reaches the fixing unit is long, naturally, the temperature rise of the fixing unit is larger than when the time is short. That is, when the time is long, the temperature of the fixing unit at the timing when the paper reaches the fixing unit is lowered even when the temperature of the fixing unit at the start of the printing operation is lower than when the time is short. The printable temperature can be set. Therefore, in the third embodiment, the processing is performed in consideration of the time from the start of the printing operation until the paper reaches the fixing unit.

  Here, the time from the start of the printing operation to the arrival of the paper at the fixing unit depends on the transport speed, and the time becomes longer as the transport speed is slower. In general, in an image forming apparatus such as a printer, the conveyance speed is set to be slow when the paper is thick. Specifically, the conveyance speed in the case of thick paper can be set to half the normal conveyance speed.

  The functional configuration of the printer 1 for controlling the start of the printing operation according to the third embodiment is the same as the configuration shown in the block diagram of FIG. However, in the third embodiment, as shown in FIG. 11, the corresponding time storage unit 311 stores a correspondence relationship between the attribute of the paper and the corresponding time according to the current print request. Here, it is assumed that the correspondence between the paper thickness and the corresponding time is stored as a specific paper attribute. In the example of FIG. 11, it is assumed that the correspondence relation considering the attribute of the sheet described in the second embodiment is stored. As described above, the thicker the paper, the longer the time from the start of the printing operation until the paper reaches the fixing means, and the fixing between the start of the printing operation and the arrival of the paper at the fixing means. The temperature rise of the means is large. Therefore, the thicker the sheet, the higher the temperature of the fixing unit can be increased to the printable temperature in the time from the start of the printing operation until the sheet reaches the fixing unit even if the temperature of the fixing unit decreases. It becomes possible. Therefore, in the third embodiment, the corresponding time is set longer as the paper is thicker, as shown in the first and fourth stages in FIG.

  The processing according to the third embodiment executed by the printer 1 is the same as the processing shown in the flowchart of FIG. However, in the processing according to the third embodiment, in step S107, the corresponding time T1 corresponding to the thickness that is the attribute of the paper included in the print request received in step S105 is read from the corresponding time storage unit 311. Is set.

  The operation timing in the printer 1 in which the processing according to the third embodiment is performed will be described with reference to FIGS. FIGS. 12A and 12B show the operation timing when a print request is made within the corresponding time T1 after the temperature control for switching to the standby temperature is performed. Specifically, FIG. 12A shows the operation timing when the paper according to the print request is plain paper, and shows the same timing as FIG. 6B. FIG. 12B shows the operation timing when the paper according to the print request is a thick paper.

  Referring to FIG. 12A, when the paper according to the print request is plain paper, in step S107, 20s is set as the corresponding time T1 from the correspondence shown in FIG. Referring to FIG. 12B, when the paper according to the print request is a thick paper, in step S107, 25s is set as the corresponding time T1 from the correspondence shown in FIG. Thereafter, in any case, the printing operation is started at the same timing as the timing described in FIG. 6B (except for the specific corresponding time T1).

  As described above, according to the third embodiment, the response time depends on the thickness of the sheet according to the print request, that is, when the sheet is thick and the conveyance speed is low, compared with the case where the conveyance speed is the normal speed. T1 is set. Therefore, as is apparent from comparing FIG. 12B and FIG. 6A, compared to the case where the corresponding time T1 is set regardless of the conveyance speed as in the first embodiment, In many cases, delay processing can be made unnecessary. Thereby, the time from the printing request to the start of the printing operation can be shortened.

[Fourth Embodiment]
As described above, the temperature of the fixing unit reaches the standby temperature when the above-described corresponding time has elapsed after the temperature control for switching the fixing unit from the printing temperature to the standby temperature is performed by the temperature control unit 301. As time further elapses, the temperature of the fixing means gradually decreases. Therefore, in the first to third embodiments, as in the conventional image forming apparatus, when a print request is received after the corresponding time when the temperature of the fixing unit is the standby temperature, the printing operation is performed after the delay time has elapsed. Was supposed to start. Furthermore, in the first to third embodiments, the delay time is determined in advance based on the time required for the temperature of the fixing unit to rise to the printing temperature.

  Incidentally, as described above, the temperature from “printing temperature” to “standby temperature” corresponds to “printable temperature”. Accordingly, the temperature of the fixing unit does not necessarily rise completely to the “printing temperature”, and printing can be performed when the “standby temperature” is reached and the “printable temperature” is reached. In other words, the elapsed time after the corresponding time has passed and the temperature of the fixing unit reaches the “standby temperature” is increased to a “printable temperature” by increasing the lowered temperature to the extent that the “standby temperature” is removed. Become. Therefore, in the fourth embodiment, in the delay process when a print request is made after the lapse of the corresponding time, a process for setting a delay time considering the lapse of time from the corresponding time to the print request is performed.

  FIG. 13 is a block diagram illustrating a specific example of a functional configuration of the printer 1 for controlling the start of the printing operation according to the fourth embodiment. The functions shown in FIG. 13 include a delay time setting unit 319 for setting a delay time, which is a time for delaying the printing operation by delay control, in addition to the functions shown in FIG. 7, and a reference for setting the delay time. It further includes a reference time storage unit 321 for storing the reference time. In the following specific example, in the process according to the second embodiment, the process for setting the delay time is further performed in the delay process when a print request is made after the corresponding time has elapsed. A specific example of the functional configuration according to the embodiment is further provided with the above configuration in addition to the functional configuration according to the second embodiment shown in FIG. However, in the delay process of the process according to the first embodiment, a process for further setting a delay time may be performed. In this case, the functional configuration according to the first embodiment shown in FIG. The above configuration is further provided.

  In the fourth embodiment, the determination unit 313 sets the elapsed time from the timing when the temperature is switched from the printing temperature to the standby temperature by the temperature control unit 301 acquired from the time measuring unit 307 and the corresponding time setting unit 309. The elapsed time T5 from when the set response time has elapsed until the print request is made is calculated based on the response time thus set and the timing when the print request unit 303 receives the print request.

  The reference time storage unit 321 stores a preset delay time such as 5s described above as the reference time T6. The delay time setting unit 319 is connected to the reference time storage unit 321 and reads the reference time T6 from the reference time storage unit 321. The delay time setting unit 319 is further connected to the determination unit 313, and acquires the elapsed time T5 calculated by the time measuring unit 307 from the determination unit 313. The delay time setting unit 319 is connected to the time measuring unit 307, the corresponding time setting unit 309, and the print request unit 303, and calculates an elapsed time T5 from when the set corresponding time has elapsed until a print request is made. May be. The delay time setting unit 319 compares the read reference time T6 and the elapsed time T5, and sets the delay time T3 based on the result. The delay processing unit 315 is connected to the delay time setting unit 319, and executes a delay process so as to delay the start of the printing operation by the set delay time T3.

  FIG. 14 is a flowchart illustrating a specific example of processing according to the fourth embodiment, which is executed by the printer 1. In the process according to the fourth embodiment shown in FIG. 14, the processes of steps S101 to S111 according to the first to third embodiments shown in the flowchart of FIG. 5 are performed. If it is determined that T2 is greater than the corresponding time T1, in other words, the print request in step S105 is made between the temperature adjustment control in step S101 and the corresponding time T1 set in step S107. If it is determined that the process has been performed thereafter (YES in step S111), the delay time setting unit 319 performs steps S201 to S209 to set the delay time T3.

  Specifically, referring to FIG. 14, when it is determined in step S111 as described above (YES in step S111), delay time setting unit 319 determines the elapsed time from when the corresponding time has elapsed until a print request is made. T5 is acquired (step S201). Further, a reference time T6 that is a preset delay time stored in the reference time storage unit 321 is read (step S203).

  The delay time setting unit 319 compares the elapsed time T5 with the reference time T6 (step S205), and if the elapsed time T5 is smaller than the reference time T6, in other words, the print request in step S105 has passed the corresponding time. If it is made before the reference time T6 that is a preset delay time elapses from the timing (YES in step S205), the delay time setting unit 319 sets the elapsed time T5 as the delay time T3 ( Step S207). On the other hand, if the elapsed time T5 is greater than the reference time T6, in other words, the print request in step S105 is made after the reference time T6 has not elapsed until the reference time T6 has elapsed since the timing at which the corresponding time has elapsed. In the case where it is determined (NO in step S205), the delay time setting unit 319 sets the reference time T6 as the delay time T3 (step S209).

  The operation timing in the printer 1 in which the processing according to the fourth embodiment shown in FIG. 14 is performed will be described with reference to FIG. FIG. 15 shows the operation timing when the print request is not made within the corresponding time T1 after the temperature adjustment control for switching to the standby temperature is performed, and thereafter, until the reference time T6. Here, it is assumed that 20 s is set as the corresponding time T1 in step S107. It is assumed that the time T4 from when the printing operation starts until the sheet reaches the fixing unit is 10 s. Further, it is assumed that the reference time T6 for setting a delay time as a preset delay time is set to 5 s.

  Referring to FIG. 15, it is assumed that the set corresponding time T1 has elapsed from time Ta when the temperature control is performed (time (Ta + T1)), and a print request is made at time Tb thereafter. At this time, the elapsed time T5 is calculated by T5 = Tb− (Ta + T1). The temperature of the fixing unit reaches the standby temperature when the corresponding time T1 elapses (Ta + T1), and thereafter decreases at the time Tb by the elapsed time T5. Therefore, when a print request is made at time Tb, first, the temperature adjustment control unit 301 performs control for raising the temperature of the fixing unit from the standby temperature to the print temperature. At that time, when the temperature of the fixing unit is increased by the elapsed time T5, the temperature of the fixing unit deviates from the standby temperature and becomes a printable temperature. Therefore, in step S207, the delay time T3 is set as the elapsed time T5. The delay process is performed, and the printing operation in step S115 is started at the time (Tb + T5) after the delay time T3, which is the elapsed time T5, has elapsed.

  FIG. 15 is compared with FIG. 6A which is the same as the timing of the printing operation with delay processing in the conventional image forming apparatus. As described above, in the specific example shown in FIG. 6A, the delay time T3 (= 5 s) and the time T4 (= 10 s) from when the printing request in step S105 is made until the paper reaches the fixing unit. It will take time. On the other hand, in the specific example shown in FIG. 15, since the delay time T3 is shortened to the elapsed time T5, the elapsed time T5 (= 1 s) from when the print request in step S105 is made until the sheet reaches the fixing means. And time T4 (= 10 s) are required. That is, even when the delay process is performed, the delay time T3 is shortened to the elapsed time T5. Therefore, the time from when the print request is made until the print operation is started can be shortened.

  The processes according to the first to fourth embodiments described above may be performed by the printer 1 or may be performed by combining two or more processes. Furthermore, it is possible to provide a program that causes a computer to execute these processes. Such a program is stored in a computer-readable recording medium such as a flexible disk attached to the computer, a CD-ROM (Compact Disk-Read Only Memory), a ROM (Read Only Memory), a RAM (Random Access Memory), and a memory card. And can be provided as a program product. Alternatively, the program can be provided by being recorded on a recording medium such as a hard disk built in the computer. A program can also be provided by downloading via a network.

  The program according to the present invention is a program module that is provided as a part of a computer operating system (OS) and calls necessary modules in a predetermined arrangement at a predetermined timing to execute processing. Also good. In that case, the program itself does not include the module, and the process is executed in cooperation with the OS. A program that does not include such a module can also be included in the program according to the present invention.

  The program according to the present invention may be provided by being incorporated in a part of another program. Even in this case, the program itself does not include the module included in the other program, and the process is executed in cooperation with the other program. Such a program incorporated in another program can also be included in the program according to the present invention.

  The provided program product is installed in a program storage unit such as a hard disk and executed. The program product includes the program itself and a recording medium on which the program is recorded.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is the schematic which shows the specific example of the cross section of the center part of the printer concerning this Embodiment. It is a figure for demonstrating a thermistor. It is a block diagram which shows the specific example of a structure of the engine part and controller part of the printer concerning this Embodiment. FIG. 3 is a block diagram illustrating a specific example of a functional configuration of a printer for controlling the start of a printing operation according to the first embodiment. It is a flowchart which shows the specific example of the process concerning 1st Embodiment. It is a figure explaining the operation timing in the printer in which the process concerning 1st Embodiment is performed. FIG. 10 is a block diagram illustrating a specific example of a functional configuration of a printer for controlling the start of a printing operation according to a second embodiment. It is a figure which shows the specific example of the corresponding | compatible time memorize | stored with the printer concerning 2nd Embodiment. It is a figure explaining the operation timing in the printer in which the process concerning 2nd Embodiment is performed. It is a figure explaining the operation timing in the printer in which the process concerning 2nd Embodiment is performed. It is a figure which shows the specific example of the corresponding | compatible time memorize | stored with the printer concerning 3rd Embodiment. It is a figure explaining the operation timing in the printer in which the process concerning 3rd Embodiment is performed. It is a block diagram which shows the specific example of the function structure of a printer for controlling the start of the printing operation concerning 4th Embodiment. It is a flowchart which shows the specific example of the process concerning 4th Embodiment. It is a figure explaining the operation timing in the printer in which the process concerning 4th Embodiment is performed.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Printer, 2 Intermediate transfer belt, 3a, 3b, 3c, 3d Photoconductor, 4a, 4b, 4c, 4d Developing part, 5a, 5b, 5c, 5d Charging part, 6a, 6b, 6c, 6d Exposure part, 7 Intermediate Transfer belt cleaner, 8 paper feed roller, 10 timing roller, 11 secondary transfer roller, 12, 12a, 12b fixing roller, 13 paper discharge roller, 14a, 14b double-sided path conveyance roller, 15 waste toner box, 16 storage unit, 18 Main motor, 19 fixing motor, 20 color developing motor, 21 developing motor, 22 double-sided path conveyance motor, 23, 24 toner supply motor, 25a, 25b, 25c, 25d toner bottle, 26a, 26b, 26c, 26d stirring blade, 28a , 28b, 28c, 28d cartridge, 29 double-sided conveyance path, 30 static elimination cloth, 31 Thermistor, 32 Paper detection sensor, 100 Engine unit, 101 Control unit, 102 Non-volatile memory, 103 Non-volatile memory, 104 Output unit, 200 Controller unit, 301 Temperature control unit, 303 Print request unit, 305 Attribute acquisition unit, 306 Attribute storage unit, 307 timing unit, 309 corresponding time setting unit, 311 corresponding time storage unit, 313 judgment unit, 315 delay control unit, 317 print control unit, 319 delay time setting unit, 321 reference time storage unit.

Claims (8)

Fixing means for thermally fixing a toner image on a print medium;
The temperature of the fixing means is a first temperature that is suitable for thermal fixing of toner onto a print medium, and a second temperature that is lower than the first temperature and lower than the temperature at which heat fixing is possible . Temperature control means for adjusting to the temperature of
A print request means for accepting a print request;
Print control means for controlling a print operation executed in response to the print request;
Delay control means for performing processing for delaying the start of the printing operation;
The temperature control unit switches the temperature of the fixing unit from the first temperature to the second temperature when the printing operation according to the printing request immediately before the current printing request received by the printing request unit is completed. A time measuring means for measuring an elapsed time since the switching control was performed;
First setting means for setting a first reference time based on an attribute of a print medium included in the immediately preceding print request;
Wherein comparing the elapsed time between the first reference time to the current print request is made, the current print request has passed the first reference time from the switching control from the switching control which is measured by the clock means If it is made later, the delay control means performs delay processing. If the current print request is made before the first reference time elapses from the switching control, the delay control means performs delay processing. Control means for causing the print control means to start the printing operation without performing ,
The attribute of the print medium is an attribute related to the heat absorption of the fixing unit, and the first setting unit is configured such that the attribute of the print medium included in the immediately preceding print request is the absorption of heat from the fixing unit. is to set the shorter the first reference time than when smaller when large, the image forming apparatus. The first setting means includes
Storage means for storing a correspondence relationship between the attribute of the print medium and the first reference time;
Obtaining means for obtaining an attribute of the print medium from the print request;
Storage means for storing at least attributes of the print medium acquired from the immediately preceding print request;
The image forming apparatus according to claim 1 , further comprising: a reading unit that reads the first reference time from the correspondence relationship based on the attribute of the print medium acquired from the immediately preceding print request . The attribute of the print medium includes at least one of a length conveyed in contact with the fixing unit of the print medium and a thickness of the print medium,
The first reference time set by the first setting means is shorter than when the print medium is transported in contact with the fixing means when the length is long, and shorter when the print medium is thick than when it is thin. even a short time, an image forming apparatus according to claim 1 or 2. It said first setting means further sets the first reference time based on the conveying speed of the printing medium in the printing operation to be performed in response to the current print request,
Said first setting means to set the conveying speed in length rather the first reference time than when fast when slow, the image forming apparatus according to any one of claims 1-3. The first setting means includes
Storage means for storing a correspondence relationship between the attribute of the print medium that affects the conveyance speed and the first reference time;
Obtaining means for obtaining the attribute of the print medium from the print request;
The image forming apparatus according to claim 4 , further comprising: a reading unit that reads the first reference time from the correspondence based on the attribute of the print medium. The attribute of the print medium includes a thickness of the print medium,
6. The image forming apparatus according to claim 4 , wherein the first reference time set by the first setting unit is longer when the print medium is thick than when the print medium is thin. The elapsed time until the current print request is made after the first reference time has elapsed from the switching control measured by the time measuring means is compared with the second reference time, and the current print request is When the switching control is performed after the first reference time has elapsed and after the second reference time has elapsed, the delay control means sets a delay time for delaying the start of the current printing operation to the second reference time. If the current print request is made before the second reference time elapses after the first reference time elapses from the switching control, the delay time is set after the first reference time elapses from the switching control. the current print request is set to the time elapsed is made from, further comprising a second setting unit, an image forming apparatus according to any one of claims 1-6. Wherein the temperature of the fixing means further comprises a temperature measurement means for measuring in a non-contact manner, the image forming apparatus according to any one of claims 1-7.

Images