JP2008246768A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a prescribed component from being excessively heated in the event of forming an image, and then to improve a throughput of forming an image. <P>SOLUTION: This image forming apparatus comprises a recording section for forming an image on a medium according to prescribed image data, a temperature detection section for detecting temperature of a prescribed component, a printing condition setting processing means for setting a printing condition according to the detected temperature and a remaining amount for printing, and a printing processing means for performing the printing according to the printing condition. As the printing condition is set according to the detected temperature and the remaining amount for printing and the printing is performed according to the printing condition, it is possible to prevent the prescribed component from being excessively heated and to improve the throughput of forming an image. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an image forming apparatus.

  2. Description of the Related Art Conventionally, in an image forming apparatus such as a printer, a copier, a facsimile machine, or a multifunction machine, for example, a dot printer, a print head as a predetermined component is set at a predetermined temperature (for example, during printing). When the temperature exceeds the alarm temperature), printing is temporarily stopped to prevent the print head from being overheated (see, for example, Patent Document 1).

In addition, in an electrophotographic printer, when a fixing unit as a predetermined part exceeds a predetermined temperature during printing, printing is temporarily stopped to prevent the fixing unit from being overheated. (For example, refer to Patent Document 2).
JP-A-6-305164 JP 2004-221968 A

  However, in the conventional printer, since it is necessary to stop image formation during printing, the print throughput as the image formation throughput is deteriorated.

  The present invention solves the problems of the conventional printer, can suppress excessive heating of a predetermined part during image formation, and can improve image formation throughput. An object is to provide an apparatus.

  Therefore, in the image forming apparatus of the present invention, based on the detected temperature and the remaining print amount, a recording unit that forms an image on a medium according to predetermined image data, a temperature detection unit that detects the temperature of a predetermined part, and the like. Printing condition setting processing means for setting printing conditions, and printing processing means for performing printing based on the printing conditions.

  According to the present invention, in the image forming apparatus, a recording unit that forms an image on a medium according to predetermined image data, a temperature detection unit that detects the temperature of a predetermined component, and the detected temperature and the remaining print amount Printing condition setting processing means for setting printing conditions, and printing processing means for performing printing based on the printing conditions.

  In this case, since printing conditions are set based on the detected temperature and the remaining printing amount and printing is performed based on the printing conditions, it is possible to suppress excessive heating of a predetermined component, and image The formation throughput can be improved.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In this case, a printer as an image forming apparatus will be described.

  FIG. 1 is a block diagram showing a printer control apparatus according to the first embodiment of the present invention.

  In the figure, reference numeral 10 denotes a dot-type print head as a recording unit, and the print head 10 is advanced and retracted in the scanning direction while being mounted on a carriage (not shown). In order to advance and retract the carriage, a scanning motor as a scanning drive source is driven. Reference numeral 20 denotes a head drive unit that drives the print head 10 to form an image, and in the present embodiment, prints. The head drive unit 20 includes a plurality of head drive units 20 disposed on the print head 10. In this embodiment, printing is performed with 24 pins protruding. For this purpose, a coil (not shown) is disposed in the head drive unit 20, and a predetermined drive current is supplied to the coil so that a pin protrudes at a predetermined drive timing. The paper is hit and printed.

  Reference numeral 11 denotes a temperature of the print head 10 as a predetermined part measured by the head thermistor 17 as a temperature sensor, that is, a head temperature detection unit as a temperature detection unit that reads and detects the head temperature, and 12 denotes a time measuring member. A time counting unit for detecting the time measured by the timer 18, 13 a data receiving unit for receiving print data as image data transmitted from a host computer (not shown) as a host device, and 14 for detecting a head temperature level. A level detection unit 15 is a printing speed determination unit 15 as a first printing condition and a speed determination unit that determines an execution printing speed to be described later as an image forming speed, and 16 is a printing as a second printing condition. The number of passes, that is, the print pass number determination unit as a pass number determination unit for determining the number of print passes, 9 is a print processing unit as a printing processing means for performing printing run printing speed has been determined and the determined printing number of passes. A control circuit is configured by the head temperature detection unit 11, the time count unit 12, the data reception unit 13, the level detection unit 14, the print speed determination unit 15, the print pass number determination unit 16, the print processing unit 19, and the like. Consists of a CPU, memory, etc. (not shown).

  The printing speed determination unit 15 and the printing pass number determination unit 16 constitute a printing condition setting processing unit.

  The data reception unit 13 includes a data reception determination unit 21 that determines whether or not print data is being received, and a data amount represented by the number of remaining print data as the remaining print amount, that is, the remaining A remaining print data amount calculation unit 22 is provided as a remaining print amount calculation unit that calculates the print data amount D.

  The remaining print data, for example, received by the data receiving unit 13 and recorded in a reception memory (not shown) but not processed, or read from the reception memory. Print data that has been edited by the control circuit and has not been printed is included.

  For print data recorded in the reception memory but not processed, the number of print data bytes recorded in the reception memory is the remaining print data amount D. For print data that has been read from the reception memory but has been edited by the control circuit and has not been printed, the number of bytes of print data being processed internally is the remaining print data amount D. Is done.

  Further, the level detection unit 14 determines the time detected by the time counting unit 12, that is, the elapsed time, and is detected by the time determination unit 23 and the head temperature detection unit 11 which determine whether a certain time has elapsed. The level determining unit 24 that determines a level representing a printing condition that is a condition for forming an image based on the head temperature that has been set, that is, the detected temperature T, and a rising temperature that calculates a rising temperature when printing is performed continuously A temperature calculation unit 25 is provided.

  When the print data is being received, the level determination unit 24 determines the level corresponding to the detected temperature T. If the print data is not being received, the level determination unit 24 can change the level corresponding to the remaining print data amount D. Determine possible levels. Therefore, the level determination unit 24 reads the detected temperature T and the remaining print data amount D, and predicts a temperature rise when printing is continued as it is at a level corresponding to the detected temperature T based on the remaining print data amount D. The level for changing the level and setting the optimum printing condition is determined.

  Then, the printing speed determination unit 15 performs a printing condition setting process, reads the level determined by the level determination unit 24, calculates the deceleration rate β corresponding to the level, and is set in advance for the type of character to be printed. The basic printing speed, that is, the basic printing speed is multiplied by the deceleration rate β to determine the printing speed at which printing is actually performed, that is, the execution printing speed. The print pass number determination unit 16 performs a print condition setting process, and determines the number of print passes corresponding to the level based on the level determined by the level determination unit 24. Note that the effective printing speed is changed by changing the moving speed when the carriage is advanced and retracted, and changing the driving timing for projecting the pins of the print head 10 correspondingly. The number of printing passes is the number of scans necessary to print one line, and can be changed by changing the number of pins that are projected when the carriage is moved.

  When the execution printing speed and the number of printing passes are determined in this way, the print processing unit 19 performs a printing process and performs printing based on the execution printing speed and the number of printing passes. In the present embodiment, the printing speed determination unit 15 and the printing pass number determination unit 16 determine the execution printing speed and the printing pass number, respectively. Only one of the number-of-times determining unit 16 can determine only one of the execution printing speed and the number of printing passes. In this case, the print processing unit 19 performs printing based on one of the execution printing speed and the number of printing passes.

  Next, the operation of the level detector 14 will be described.

  FIG. 2 is a first flowchart showing the operation of the level detection unit in the first embodiment of the present invention. FIG. 3 is a second flowchart showing the operation of the level detection unit in the first embodiment of the present invention. FIG. 4 is a time chart showing the transition of the head temperature in the first embodiment of the present invention.

  First, the time determination unit 23 (FIG. 1) reads the time counted by the time counting unit 12 in order to perform processing at a constant cycle, determines whether or not the predetermined time has passed, When the time has elapsed, in the data receiving unit 13, the data receiving determination unit 21 determines whether print data is being received. If the print data is not being received at the predetermined time, it is determined that the reception of the print data has been completed.

  Since the remaining print data amount D cannot be calculated when print data is being received, the level determination unit 24 reads the detected temperature T, determines the level corresponding to the detected temperature T, and sets it.

  For this purpose, a level determination map is set in a storage device (not shown) of the level detection unit 14, and the detected temperature T and the level are recorded in the level determination map in association with each other. The level determination unit 24 reads the level corresponding to the detected temperature T with reference to the level determination map. The level determination map is created based on the characteristics shown in Table 1 below and FIG.

  In this case, the detected temperature T is set to level 1 in the range of the temperature T0 or more and less than the temperature T1 (65 [° C.]), and is in the range of the temperature T1 or more and less than the temperature T2 (85 [° C.]) 2 and set to level 3 in the range of temperature T2 or more and less than temperature T3 (105 [° C.]), and set to level 4 in the range of temperature T3 or more and less than temperature T4 (115 [° C.]), Level 5 is set in the range of temperature T4 or more and less than temperature T5 (125 [° C.]), level 6 is set in the range of temperature T5 or more and less than temperature T6 (135 [° C.]), and temperature T6 or more. , Level 7. The temperature T0 is a temperature when printing is started, and the temperature T6 is a temperature for stopping printing (limit) at which printing needs to be stopped.

  When print data is not being received, the level determination unit 24 reads the detected temperature T, determines a level corresponding to the detected temperature T, and sets the determined level as a level a representing an initial value in the storage device. Record.

  Subsequently, the rising temperature calculation unit 25 reads the level a and the remaining print data amount D, and reads the rising temperature Tup corresponding to the remaining print data amount D at the level a with reference to the rising temperature map. For this purpose, a rising temperature map is set in the storage device, and the level a, the remaining print data amount D and the rising temperature Tup are recorded in correspondence with the rising temperature map. The rising temperature map is created based on the characteristics shown in Table 2.

  In this case, if printing is continued for the remaining print data amount D at a predetermined level, the head temperature increases, and the rising temperature Tup represents the increase in head temperature at that time.

Next, the level determination unit 25 determines the difference TX between the detected temperature T and the temperature T6 for stopping printing that becomes a limit when printing is continued.
TX = T6-T
Is calculated.

  By the way, if printing is continued for the remaining print data amount D, the head temperature becomes high. If the rising temperature at that time is Tup, if the rising temperature Tup is higher than the difference TX, printing is continued as it is. The head temperature reaches level 7. On the other hand, when the rising temperature Tup is lower than the difference TX, the head temperature does not reach level 7 even if printing is continued under the same printing conditions.

  Therefore, the level determination unit 24 determines whether or not the rising temperature Tup is higher than the difference TX. If the rising temperature Tup is higher than the difference TX, the level determination unit 24 changes the printing condition (print execution speed and number of printing passes) Increase and change.

  For this purpose, the level determination unit 24 sets level b as a parameter for changing the level to level 1. Subsequently, the rising temperature calculation unit 25 reads the rising temperature Tup when printing is performed at level 1 with reference to the rising temperature map. Then, the level determination unit 24 determines whether or not the rising temperature Tup is higher than the difference TX, and when the rising temperature Tup is higher than the difference TX, the level b is increased to level 2.

  Similarly, the rising temperature calculation unit 25 reads the rising temperature Tup when printing is performed at level 2, and the level determination unit 24 determines whether the rising temperature Tup is higher than the difference TX, and the rising temperature Tup is If it is higher than the difference TX, level b is increased to level 3.

  While the rising temperature Tup is higher than the difference TX, the level determination unit 24 keeps increasing the level b. When the level b becomes higher than the level 6, the level determination unit 24 reaches level 7 when the level b is further increased and printing is continued. Resulting in.

  Therefore, the level determination unit 24 determines that the rising temperature Tup cannot be made equal to or lower than the difference TX even if the level b is increased, and determines and sets the level corresponding to the detected temperature T.

  On the other hand, if the rising temperature Tup becomes the difference TX or less before the level b becomes higher than the level 6, the level determination unit 24 determines whether or not the level b at that time is higher than the initial level a. To do. When the level b is higher than the level a, the printing speed can be increased by continuing the printing at the level a corresponding to the detected temperature T, so the level determination unit 24 sets the level a. Further, when the level b is equal to or lower than the level a, the printing speed can be increased by performing the printing at the level b. Therefore, the level determination unit 24 sets the level b.

  In this way, the levels used to determine the printing speed and the number of printing passes can be set.

  As described above, based on the remaining print data amount D, it is possible to determine whether printing can be continued at a level at which the printing speed can be higher than the current printing condition, and printing can be continued. In this case, since the printing conditions are changed, the printing time can be shortened.

Next, a flowchart will be described.
Step S1: It is determined whether or not a certain time has passed. If the predetermined time has elapsed, the process proceeds to step S2, and if not, the process ends.
Step S2: It is determined whether reception is in progress. If it is being received, the process proceeds to step S3. If it is not being received, the process proceeds to step S4.
Step S3: A level corresponding to the detected temperature T is set, and the process proceeds to Step S14.
Step S4: A level a corresponding to the detected temperature T is recorded.
Step S5: The difference TX is calculated.
Step S6: Level 1 is set to level b which is a parameter for changing the level.
Step S7: The temperature rise Tup when printing is performed at level 1 is read.
Step S8: It is determined whether the rising temperature Tup is higher than the difference TX. When the rising temperature Tup is higher than the difference TX, the process proceeds to step S9, and when the rising temperature Tup is equal to or lower than the difference TX, the process proceeds to step S11.
Step S9: Increase level b.
Step S10: It is determined whether level b is higher than level 6. If level b is higher than level 6, the process returns to step S3. If level b is lower than level 6, the process returns to step S7.
Step S11: Determine whether level a is lower than level b. If level a is lower than level b, the process proceeds to step S12. If level a is greater than or equal to level b, the process proceeds to step S13.
Step S12: Level a is determined.
Step S13: Determine level b.
Step S14: Reset the counter and end the process.

  By the way, in the present embodiment, the printing condition is changed based on the remaining print data amount D. However, when the printing of the remaining print data amount D is continued, the print duty, that is, If the print duty is different, the load applied to the print head 10 is different, so the head temperature rise temperature Tup is also different. Therefore, it becomes difficult to change the printing conditions accurately.

  Therefore, a second embodiment of the present invention will be described in which the printing conditions can be accurately changed even when the printing duty is different. In addition, about the thing which has the same structure as 1st Embodiment, the same code | symbol is provided and the effect of the same embodiment is used about the effect of the invention by having the same structure.

  FIG. 5 is a block diagram showing a printer control apparatus according to the second embodiment of the present invention, FIG. 6 is a first flowchart showing the operation of the level detection unit according to the second embodiment of the present invention, and FIG. It is a 2nd flowchart which shows operation | movement of the level detection part in the 2nd Embodiment of this invention.

  In this case, the data receiving unit 13 includes a print duty calculating unit 26 as a duty calculating unit, and the level detecting unit 14 includes a duty level determining unit 27. The print duty calculator 26 determines a print mode based on the command and print data received by the data receiver 13 and calculates the print duty dy of the print data.

  The print duty dy indicates the ratio of the number of dots printed to the number of dots of 100 [%]. In this case, the number of dots to be printed is recorded in the reception memory, but for print data that has not been processed, it represents the number of dots in the print data recorded in the reception memory and is read from the reception memory. However, for print data that has been edited by the control circuit and has not been printed, this represents the number of dots of print data that are being processed internally.

  When there are a plurality of lines of remaining print data, the number of dots of 100 [%] in the plurality of lines is calculated, so the print duty dy is the ratio of the number of dots printed to the number of dots of 100 [%]. .

  Further, the duty level determination unit 27 reads the print duty dy calculated by the print duty calculation unit 26, and applies to the print head 10 as a recording unit and a predetermined component based on the print duty dy. A duty level representing the load is determined. For this purpose, a duty level map is set in the storage device, and the print duty dy range and duty levels A to C are recorded in correspondence with the duty level map. The duty level determination unit 27 reads the duty levels A to C corresponding to the printing duty dy with reference to the duty level map. The duty level map is created based on the characteristics shown in Table 3.

  In this case, when the print duty dy is 80% or more, the duty level is set to A (high duty), and when the print duty dy is 50% or more and less than 80%, the duty level is Is set to B (medium duty), and when the print duty dy is less than 50%, the duty level is set to C (low duty).

  In this embodiment, the rising temperature calculation unit 25 reads the remaining print data amount D and the duty levels A to C, and reads the rising temperature Tup corresponding to the remaining print data amount D and the duty levels A to C. .

  Subsequently, the level determination unit 24 reads the duty levels A to C determined by the duty level determination unit 27 and the remaining print data amount D, calculates a rising temperature Tup when printing is performed at each level, and The level is set based on the rising temperature Tup.

  For this purpose, a rising temperature map comprising submaps for each duty level A to C is set in the storage device, and the level and the remaining print data amount D and the rising temperature Tup are recorded in correspondence with each submap. The

  The level determining unit 24 refers to the rising temperature map, selects a submap corresponding to the duty levels A to C, and refers to the submap to increase the temperature Tup corresponding to the level and the remaining print data amount D. Is read. The submap corresponding to the duty level A is created based on the characteristics shown in Table 4, the submap corresponding to the duty level B is created based on the characteristics shown in Table 5, The submap corresponding to the duty level C is created based on the characteristics shown in Table 6.

  As described above, for each print duty, it is determined whether printing can be continued at a level at which the printing speed can be higher than the current printing conditions based on the remaining print data amount D. Therefore, it can be accurately determined whether printing can be continued.

Next, a flowchart will be described.
Step S21: It is determined whether a certain time has elapsed. If the predetermined time has elapsed, the process proceeds to step S22. If not, the process ends.
Step S22: It is determined whether or not reception is in progress. If it is being received, the process proceeds to step S23. If it is not being received, the process proceeds to step S24.
Step S23: A level corresponding to the detected temperature T is set, and the process proceeds to Step S34.
Step S24: A level a corresponding to the detected temperature T is recorded.
Step S25: The difference TX is calculated.
Step S26: Level 1 is set to level b which is a parameter for changing the level.
Step S27: Read the remaining print data amount D and the rising temperature Tup corresponding to the duty levels A to C.
Step S28: Determine whether the rising temperature Tup is higher than the difference TX. When the rising temperature Tup is higher than the difference TX, the process proceeds to step S29, and when the rising temperature Tup is equal to or lower than the difference TX, the process proceeds to step S31.
Step S29: Level b is increased.
Step S30: It is determined whether level b is higher than level 6. If level b is higher than level 6, the process returns to step S23. If level b is lower than level 6, the process returns to step S27.
Step S31: Determine whether level a is lower than level b. If level a is lower than level b, the process proceeds to step S32. If level a is greater than or equal to level b, the process proceeds to step S33.
Step S32: Determine level a.
Step S33: Determine level b.
Step S34: Reset the counter and end the process.

  Next, a third embodiment of the present invention will be described. In addition, about the thing which has the same structure as the said 1st, 2nd embodiment, the same code | symbol is provided and the effect of the embodiment is used about the effect of the invention by having the same structure.

  FIG. 8 is a schematic diagram of a printer according to the third embodiment of the present invention, FIG. 9 is a first block diagram showing a printer control apparatus according to the third embodiment of the present invention, and FIG. FIG. 11 is a block diagram showing a control circuit according to the third embodiment of the present invention. FIG. 11 is a second block diagram showing a printer control apparatus according to the third embodiment.

  In the figure, the printer has first to fourth printing mechanisms P1 to P4 arranged in tandem in order along the transport direction of the paper 121 as a medium, and the first to fourth printing mechanisms P1 to P4. Are each composed of an electrophotographic LED printing mechanism. The first to fourth printing mechanisms P1 to P4 constitute first to fourth image forming mechanisms.

  The first printing mechanism P1 exposes the surface of the image forming unit 112Bk as the black recording unit and as the image forming unit, and the surface of the photosensitive drum 116Bk as the image carrier according to the print data as the image data. It comprises an LED head 113Bk as an apparatus and a transfer roller 114Bk as a transfer member for transferring a toner image as a black developer image formed by the image forming unit 112Bk onto a sheet 121 such as plain paper or an OHP sheet.

  The second printing mechanism P2 serves as a yellow recording unit and an image forming unit 112Y as an image forming unit, and an exposure device that exposes the surface of the photosensitive drum 116Y as an image carrier in accordance with print data. And a transfer roller 114Y as a transfer member for transferring a toner image as a yellow developer image formed by the image forming unit 112Y to the paper 121.

  The third printing mechanism P3 serves as a magenta recording unit and an image forming unit 112M serving as an image forming unit, and an exposure device that exposes the surface of the photosensitive drum 116M serving as an image carrier in accordance with print data. And a transfer roller 114M as a transfer member for transferring a toner image as a magenta developer image formed by the image forming unit 112M to the paper 121.

  Further, the fourth printing mechanism P4 serves as a cyan recording unit and an image forming unit 112C as an image forming unit, and an exposure device that exposes the surface of the photosensitive drum 116C as an image carrier in accordance with print data. And a transfer roller 114 </ b> C as a transfer member for transferring a toner image as a cyan developer image formed by the image forming unit 112 </ b> C onto the paper 121.

  Each of the image forming units 112Bk, 112Y, 112M, and 112C has the same structure, and the photosensitive drums 116Bk, 116Y, 116M, and 116C that are rotated in the direction of the arrow, and the photosensitive drums 116Bk, 116Y, 116M, and 116C. The charging rollers 117Bk, 117Y, 117M, and 117C as charging devices that uniformly and uniformly charge the surface of the toner and the developing units 118Bk, 118Y, 118M, and 118C. The developing units 118Bk, 118Y, 118M, and 118C have developing rollers 119Bk, 119Y, 119M, and 119C as developer carriers, and the developing rollers 119Bk, 119Y, 119M, and 119C are semiconductive rubber materials. The developing blade 155 and the sponge roller 156 are brought into pressure contact with each other. In addition, the image forming units 112Bk, 112Y, 112M, and 112C are integrated with a toner cartridge 157 as a developer cartridge that accommodates toner as a developer of each color of non-magnetic one component, or the image forming units 112Bk, 112Y. , 112M and 112C are detachably disposed on the main body, and the toner of each color is supplied to the developing units 118Bk, 118Y, 118M and 118C from a supply port (not shown) formed at the bottom of the toner cartridge 157.

  A cleaning blade 195 as a cleaning device is disposed in pressure contact with each of the photosensitive drums 116Bk, 116Y, 116M, and 116C, and scrapes toner remaining on the surface of the photosensitive drums 116Bk, 116Y, 116M, and 116C after transfer. Drop it. The scraped toner is stored in a waste toner box (not shown) by the spiral screw 158.

  Next, functions of the developing units 118Bk, 118Y, 118M, and 118C will be described.

  The toner supplied from each toner cartridge 157 is sent to the developing rollers 119Bk, 119Y, 119M, and 119C via the sponge roller 156, and a thin layer is formed on the surface of the developing rollers 119Bk, 119Y, 119M, and 119C by the developing blade 155. And reaches the contact surface with the photosensitive drums 116Bk, 116Y, 116M, and 116C. When the toner is thinned, the toner is strongly rubbed and charged by the developing rollers 119Bk, 119Y, 119M, and 119C and the developing blade 155. In this embodiment, the toner is charged to a negative polarity, and reversal development is performed.

  Next, the LED heads 113Bk, 113Y, 113M, and 113C will be described.

  The LED heads 113Bk, 113Y, 113M, and 113C include an LED array (not shown), a drive IC (not shown) that drives the LED array, a substrate (not shown) that mounts the drive IC, and a rod (not shown) that collects light from the LED array. It consists of a lens array or the like, and selectively emits the LED elements of the LED array according to the print data, thereby forming electrostatic latent images on the surfaces of the photosensitive drums 116Bk, 116Y, 116M, and 116C. Then, toner on the developing rollers 119Bk, 119Y, 119M, and 119C is attached to the electrostatic latent image by electrostatic force to form a toner image.

  In addition, a transport belt 120 as an endless belt is movably disposed in contact with each of the image forming units 112Bk, 112Y, 112M, and 112C. Each transfer part between 116M, 116C and the transfer rollers 114Bk, 114Y, 114M, 114C is caused to travel.

  The conveyance belt 120 is made of a high-resistance semiconductive plastic film, and is stretched between a driving roller 131, a driven roller 132, and a tension roller (not shown). When the sheet 121 is separated by the electrostatic force and the sheet 121 is separated from the transport belt 120, the static electricity remaining on the transport belt 120 is set within a range that is naturally discharged.

  The driving roller 131 is connected to a motor 174 as driving means for belt running, and is rotated in the direction of arrow f by the motor 174 to run the conveyor belt 120.

  The upper half of the conveyor belt 120 is stretched through the transfer portions of the first to fourth printing mechanisms P1 to P4, and the tip of a cleaning blade 134 as a cleaning device is brought into contact with the lower half of the conveyor belt 120. It is done. The cleaning blade 134 is made of a flexible rubber material or plastic material, and scrapes off the toner remaining on the surface of the conveying belt 120 into a waste toner tank 135. Further, a temperature detection sensor 188 as a temperature detection unit is disposed in contact with the conveyance belt 120.

  A paper feed mechanism 136 is disposed on the lower right side of the printer. The sheet feeding mechanism 136 includes a medium storage cassette, a hopping mechanism, and a registration roller 145. The medium storage cassette includes a medium storage box 137, a push-up plate 138, and a pressing member 139. The hopping mechanism includes a discriminating member 140, a spring 141, and a paper feed roller 142, and the discriminating means 140 is pressed against the paper feed roller 142 by the spring 141.

  In this case, the paper 121 stored in the medium storage box 137 is pressed against the paper supply roller 142 by the pressing member 139 via the push-up plate 138, and the paper supply roller 142 is rotated by driving a paper supply motor (not shown). As a result, the discriminating member 140 pressed against the paper feed roller 142 by the spring 141 discriminates one by one and is fed to the registration roller 145.

  Subsequently, the sheet 121 is sent between the suction roller 147 and the conveyance belt 120. The suction roller 147 is pressed against the driven roller 132 via the transport belt 120, charges the paper 121 sent from the paper feed mechanism 136, and sucks the transport belt 120 by electrostatic force. Therefore, the suction roller 147 is made of a high resistance semiconductive rubber material. Between the suction roller 147 and the image forming unit 112Bk, a photo sensor 152 as a first medium detecting unit that detects the front end of the paper 121 is disposed. Further, a photo sensor 153 as a second medium detection unit that detects the rear end of the paper 121 is disposed on the downstream side of the image forming unit 112 </ b> C in the conveyance direction of the paper 121.

  Further, on the downstream side of the photosensor 153 in the conveyance direction of the paper 121, a fixing device for fixing the toner images of the respective colors transferred to the paper 121 in the transfer portions of the first to fourth printing mechanisms P1 to P4. A fixing device 148 is provided. The fixing device 148 includes a heat roller 149 as a first fixing roller that heats the toner on the paper 121 and a pressure roller 150 as a second fixing roller that presses the paper 121 toward the heat roller 149. Have.

  The heat roller 149 is formed by coating an elastic body such as silicone rubber on a mandrel such as aluminum and coating the surface of the elastic body with a fluororesin for preventing offset. The pressure roller 150 is formed by coating an elastic body such as silicone rubber on a mandrel such as aluminum. A thermistor 159 is disposed opposite to the heat roller 149, the temperature of the heat roller 149 is detected by the thermistor 159, and the fixing device 148 has a predetermined fixing temperature according to the detected temperature representing the detected temperature. That is, the heater (not shown) in the heat roller 149 can be controlled to be turned on / off so that the fixing control temperature is reached.

  Further, a discharge port 151 is disposed on the downstream side of the fixing device 148 in the conveyance direction of the paper 121, and a discharge stacker 196 is disposed outside the discharge port 151. After the color image is formed and printing is completed, the sheet 121 is discharged to the discharge stacker 196 through the discharge port 151.

  9 to 11, reference numeral 161 denotes a control circuit. The control circuit 161 includes memories such as a hard disk 240, an intermediate buffer 250, and a frame buffer 260 in addition to the CPU 220, the hard disk interface 230, and the like. A print processing unit (not shown) 161 performs print processing, and controls the print operation of the entire printer based on print data (for example, PDL data) received from the host computer via the interface unit 170 and control commands. And printing by forming a color image. The interface unit 170 transmits information representing the printer status to the host computer, analyzes a control command received from the host computer, and records the received print data in the reception memory 167 for each color. . The print data input via the interface unit 170 is edited by the control circuit 161 and sent to the LED heads 113Bk, 113Y, 113M, and 113C as image data (video signals) of each color.

  Reference numeral 154 denotes an operation panel as an operation unit, and the operation panel 154 includes an LED (not shown) for displaying the status of the printer and a switch (not shown) for an operator to input an instruction to the printer.

  In addition to the photo sensors 152 and 153, the thermistor 159, etc., a sensor unit 190 includes a sensor (not shown) that detects the temperature and humidity of each part inside the printer, and a sensor (not shown) that detects the density of the color image. The sensor output of each sensor of the sensor unit 190 is sent to the control circuit 161.

  The control circuit 161 is connected to a charging voltage control unit 177, a head control unit 179, a development voltage control unit 181, a transfer voltage control unit 183, a motor control unit 185, a fixing control unit 187, and a conveyance motor control unit 160. The

  The charging voltage controller 177 receives an instruction from the control circuit 161 and applies voltages to the charging rollers 117Bk, 117Y, 117M, and 117C to charge the surfaces of the photosensitive drums 116Bk, 116Y, 116M, and 116C. Control for. The charging voltage control unit 177 performs control for each color, and includes charging voltage control units 178Bk, 178Y, 178M, and 178C.

  The head control unit 179 receives an instruction from the control circuit 161, receives print data of each color recorded in the frame buffer 260, and then sends the print data to each LED head 113Bk, 113Y, 113M, 113C, and the LED elements of the LED array Are selectively emitted to form electrostatic latent images on the surfaces of the photosensitive drums 116Bk, 116Y, 116M, and 116C. The head control unit 179 performs control for each color and includes head control units 180Bk, 180Y, 180M, and 180C.

  The developing voltage controller 181 receives an instruction from the control circuit 161, applies a voltage to the developing rollers 119Bk, 119Y, 119M, and 119C, and is formed on the surface of the photosensitive drums 116Bk, 116Y, 116M, and 116C. Each color toner is attached to the electrostatic latent image to form a toner image of each color. The development voltage controller 181 controls each color and includes development voltage controllers 182Bk, 182Y, 182M, and 182C.

  The transfer voltage controller 183 receives an instruction from the control circuit 161 and applies a voltage to the transfer rollers 114Bk, 114Y, 114M, and 114C, and is formed on the surface of each of the photosensitive drums 116Bk, 116Y, 116M, and 116C. The transferred toner image is transferred to the paper 121. The transfer voltage control unit 183 includes transfer voltage control units 184Bk, 184Y, 184M, and 184C for performing control for each color and sequentially transferring the toner images of the respective colors onto the paper 121.

  The motor control unit 185 receives instructions from the control circuit 161, and rotates the respective photosensitive drums 116Bk, 116Y, 116M, and 116C and the developing rollers 119Bk, 119Y, 119M, and 119C. 128M and 128C are driven. The motor control unit 185 performs control for each color, and includes motor control units 186Bk, 186Y, 186M, and 186C.

  The fixing control unit 187 receives an instruction from the control circuit 161 and applies a voltage to a heater built in the fixing device 148. The fixing control unit 187 controls on / off of the heater based on the temperature detected by the thermistor 159, and drives the motor 175 when the fixing device 148 reaches the fixing control temperature, and the heat roller 149 and The pressure roller 150 is rotated.

  The transport motor controller 160 drives the motor 174 to cause the transport belt 120 to travel. Reference numeral 189 denotes a temperature detection measurement circuit, which converts the sensor output of the temperature detection sensor 188 into a detection voltage and sends it to the control circuit 161.

  Next, the format of a job (print job) spooled in the hard disk 240 will be described.

  FIG. 12 is a diagram showing a print job format according to the third embodiment of the present invention.

  Each job spooled in the hard disk 240 (FIG. 11) has a header, which includes a job ID (JOB ID) for specifying the job, the total number of pages of the job (TOTAL PAGES), The number of pages that are not printed in the job, that is, the number of unprinted pages (UNPRINTED PAGES), the number of pages that have already been printed, that is, the number of printed pages (PRINTED PAGES), and the like are recorded. When initially spooled to the hard disk 240, the number of unprinted pages is made equal to the total number of pages. Each time printing of one page is completed, the number of unprinted pages is decreased. Here, when printing of one page is completed, internal data (intermediate data) of one page is generated, and image data of one page is generated from the frame buffer 260 by each developing roller 119Bk (FIG. 9), 119Y, 119M, 119C indicates the end of sending. When the printing of one page is completed, there is no intermediate data in the intermediate buffer 250, and when the number of unprinted pages becomes zero (0), the print job is deleted from the hard disk 240.

  Next, the operation of the printer having the above configuration will be described.

  When the control circuit 161 receives print data and a control command transmitted from the host computer via the interface unit 170, the control circuit 161 sends a predetermined instruction to the fixing control unit 187 (FIG. 10), and the fixing control unit 187 The detected temperature at 159 is read to determine whether the temperature of the fixing device 148 falls within the usable temperature range. When the temperature of the fixing device 148 does not fall within the usable temperature range, the fixing control unit 187 turns on the heater and heats the fixing device 148 until the temperature is within the temperature range. When the temperature of the fixing device 148 reaches a predetermined temperature and falls within the usable temperature range, the fixing control unit 187 drives the motor 175 to rotate the heat roller 149 and the pressure roller 150.

  Next, the control circuit 161 sends a predetermined instruction to the motor control unit 185, and the motor control unit 185 drives each of the motors 128Bk, 128Y, 128M, 128C, and each of the photosensitive drums 116Bk, 116Y, 116M, 116C and the developing rollers 119Bk, 119Y, 119M, and 119C are rotated. Further, the control circuit 161 sends predetermined instructions to the charging voltage control unit 177, the development voltage control unit 181 and the transfer voltage control unit 183, and each charging voltage control unit 177, the development voltage control unit 181 and the transfer voltage control unit 183. Applies a voltage to each LED head 113Bk, 113Y, 113M, 113C, each developing roller 119Bk, 119Y, 119M, 119C and each transfer roller 114Bk, 114Y, 114M, 114C.

  The control circuit 161 reads the remaining amount and size of the sheet 121 set in the medium storage box 137 (FIG. 8) detected by the medium remaining amount sensor and the medium size sensor, and makes them correspond to the type of the sheet 121. In order to carry the paper, a predetermined instruction is sent to the carry motor control unit 160, and the carry motor control unit 160 drives the motor 174 to rotate the drive roller 131 to start carrying the paper 121. In this case, the motor 174 can be driven in both directions. First, when the motor 174 is driven in the opposite direction, the paper feed roller 142 is rotated and the paper 121 is taken out from the medium storage box 137. The sheet is conveyed by a preset amount until the front end of the sheet 121 is detected by a medium suction port sensor (not shown). Subsequently, when the motor 174 is driven in the forward direction, the registration roller 145 is rotated, and the sheet 121 is sent to the transfer unit of the first printing mechanism P1.

  When the paper 121 reaches a predetermined position, the control circuit 161 reads the image data from the frame buffer 260 and sends it to the head controller 179. Upon receiving image data for one line, the head controller 179 sends image data and a latch signal to the LED heads 113Bk, 113Y, 113M, and 113C, and holds the image data in the LED heads 113Bk, 113Y, 113M, and 113C. Let The head controller 179 sends a print drive signal STB to each LED head 113Bk, 113Y, 113M, 113C. As a result, each LED head 113Bk, 113Y, 113M, 113C The LED elements of the array are selectively lit.

  The LED heads 113Bk, 113Y, 113M, and 113C irradiate the photosensitive drums 116Bk, 116Y, 116M, and 116C charged to a negative polarity, and the surfaces of the photosensitive drums 1116Bk, 116Y, 116M, and 116C are irradiated. Then, an electrostatic latent image is formed by forming dots with high potential. Then, the toner charged to a negative polarity is attracted to each dot by an electrical attraction force, and a toner image of each color is formed. Thereafter, the toner images are sent to the transfer portions of the first to fourth printing mechanisms P1 to P4. At this time, the control circuit 161 sends an instruction to the transfer voltage control unit 183, and the transfer voltage control unit 183 applies a transfer voltage having a positive polarity to the transfer rollers 114Bk, 114Y, 114M, and 114C. As a result, the transfer rollers 114Bk, 114Y, 114M, and 114C sequentially transfer the toner images of the respective colors onto the paper 121 that passes through the transfer portions, and form a color toner image on the paper 121.

  Then, the paper 121 on which the color toner image is formed is sent to the fixing device 148, where the toner image is heated and pressurized and fixed on the paper 121 to form a color image. Thereafter, the sheet 121 is further conveyed, passes through a sheet discharge port sensor (not shown), and is discharged to the discharge stacker 196.

  When the paper 121 passes through the paper discharge port sensor, the control circuit 161 causes the LED heads 113Bk, 113Y, 113M, 113C, developing rollers 119Bk, 119Y, 119M, 119C, transfer rollers 114Bk, 114Y, 114M, 114C, and the like. The application of the voltage is terminated, and at the same time, the driving of the motors 128Bk, 128Y, 128M, 128C and the motors 174, 175 is stopped.

  By the way, a large number of drive members for performing a series of operations are arranged inside the printer, and each drive member generates heat as a heat source. Among the driving members, in particular, the heat roller 149 is controlled at a high temperature exceeding 150 ° C. in order to fix the color toner image formed on the paper 121 and becomes a large heat source. The motors 128Bk, 128Y, 128M, 128C, 174, 175 and the like also serve as heat sources during driving.

  Therefore, when the environment changes or the number of continuous prints increases, the heat from the heat sources in the printer, particularly in the region between the fixing device 148 and the fourth printing mechanism P4, is increased. The ambient temperature exceeds 50 [° C.].

  In general, when the temperature of the toner becomes extremely high, the fluidity in each of the image forming units 112Bk, 112Y, 112M, and 112C decreases, and the toner conveying ability by the developing rollers 119Bk, 119Y, 119M, and 119C decreases. . As a result, the toner continues to be agitated in the developing units 118Bk, 118Y, 118M, and 118C and aggregates, so that the reproducibility of the halftone density requiring a fine color tone is lowered, the gamma characteristic is improved, and the continuous tone The smoothness of change will be lost.

  Further, the toner has a low charge amount under high-temperature and high-humidity environmental conditions, and if a toner with a small charge amount is used, the toner adheres to the non-image forming area on the paper 121 and a ground cover is formed. Further, since the toner softens and becomes coagulated as the temperature rises, the coagulated toner becomes charged rollers 117Bk, 117Y, 117M, and 117C, and photosensitive drums 116Bk, 116Y, 116M, and 116C, and the like. If it adheres to the surface, the surface potential of the photoconductive drums 116Bk, 116Y, 116M, and 116C decreases, and a ground cover is formed.

  Therefore, the toner temperature or the surface temperature of the photosensitive drums 116Bk, 116Y, 116M, and 116C is detected in the photosensitive drums 116Bk, 116Y, 116M, and 116C for each of the first to fourth printing mechanisms P1 to P4, and the toner is detected. Although it is desirable to suppress the temperature of the photosensitive drums 116Bk, 1116Y, 116M, and 116C from increasing, the image forming units 112Bk, 112Y, 112M, and 112C include, for example, toner temperatures or photosensitive drums. It is difficult to dispose a thermistor for detecting the surface temperature of 116Bk, 116Y, 116M, and 116C, and a special photosensitive material is formed into a thin film on the surface of the photoconductor drums 116Bk, 116Y, 116M, and 116C. It is applied and a delicate photosensitive layer is formed. Pressing the data directly photosensitive drum 116Bk, 116Y, 116M, detects a surface temperature of 116C, photosensitive drums 116Bk, 116Y, 116M, scratched surface 116C, thus hindered in the image forming process. A method for detecting the surface temperature of the photoconductive drums 116Bk, 116Y, 116M, and 116C by a non-contact method is conceivable. In this case, not only the cost of the sensor is increased, but also a space for mounting the sensor is required. It cannot be secured.

  Therefore, in the present embodiment, the photosensitive drums 116Bk, 116Y, 116M, and 116C are brought into contact with each other, and the surface temperature of the conveyor belt 120 that is heated to substantially the same temperature is detected, thereby detecting the photosensitive drums 116Bk and 116Y. , 116M and 116C are estimated and detected, and the printer is controlled based on the detected surface temperatures of the photosensitive drums 116Bk, 116Y, 116M and 116C.

  Therefore, a temperature detection sensor 188 is disposed below the heat roller 149 in a position where it is not directly affected by the heat of the heat roller 149 and is in contact with the conveyance belt 120. The surface temperature of the conveyance belt 120 as a predetermined part after the separation is detected. Since the position where the temperature detection sensor 188 is disposed is a position close to the photosensitive drum 116C on the downstream side of the photosensitive drum 116C in the traveling direction of the conveying belt 120, the conveying belt that has passed through the photosensitive drum 116C. The surface temperature of 120 and the surface temperature of the photosensitive drum 116C are substantially equal. Further, the position where the temperature detection sensor 188 is disposed is also a position facing the driving roller 131 via the conveyor belt 120. However, the driving roller 131 and each of the photosensitive drums 116Bk, 116Y, 116M, and 116C are However, since a shaft made of an aluminum tube (not shown) is provided and the temperature characteristics are the same, the temperature of the driving roller 131 and the surface temperature of each of the photosensitive drums 116Bk, 116Y, 116M, and 116C are substantially equal.

  Since the temperature detection sensor 188 is opposed to the curved portion on the drive roller 131, the temperature detection sensor 188 can be easily pressed against the conveyance belt 120.

  The sensor output of the temperature detection sensor 188 is converted into a detection voltage by the temperature detection measurement circuit 189, and the detection voltage is sent to the control circuit 161. A temperature detection processing unit (not shown) of the control circuit 161 performs a temperature detection process, reads the detected voltage, and converts it into a detected temperature of the conveyor belt 120.

  FIG. 13 is a block diagram of a temperature detection measurement circuit according to the third embodiment of the present invention, and FIG. 14 is a diagram showing a temperature table according to the third embodiment of the present invention.

  In the figure, 162 is a power supply system of 5 [V], 163 is a ground of 0 [V], and a temperature detection sensor 188 and a reference resistor R1 are connected in series between the power supply system 162 and the ground 163, One end of the output resistor R2 is connected between the temperature detection sensor 188 and the reference resistor R1, and the other end of the output resistor R2 is connected to the control circuit 161. The reference resistance R1 and the output resistance R2 constitute a temperature detection measurement circuit 189.

  The temperature detection sensor 188 is composed of a thermistor, and the thermistor has characteristics as shown in the temperature table of FIG. 14. The higher the detected temperature, the smaller the resistance value, and accordingly, the temperature detection measurement. The detection voltage output from the circuit 189 increases.

  By the way, the print data sent from the host computer is once recorded in the reception memory 167 (FIG. 9) as described above. Subsequently, in the control circuit 161, the CPU 220 (FIG. 11) receives the reception memory 167. The print data is read out from the image data, written as a job on the hard disk 240 via the hard disk interface 230, and spooled in units of pages. Then, the CPU 220 reads one page of print data in the job from the hard disk 240, converts it into intermediate data, records it in the intermediate buffer 250, reads the intermediate data from the intermediate buffer 250, and converts it into simpler internal data. And recorded in the frame buffer 260. Subsequently, the CPU 220 reads internal data from the frame buffer 260, generates image data based on the pattern information, and sends it to the head controller 179.

  Incidentally, in the present embodiment, the remaining number of prints is calculated as the remaining print amount based on the print data spooled in the hard disk 240, and the printing conditions are changed according to the remaining print number.

  15 is a flowchart showing the operation of the printer according to the third embodiment of the present invention, FIG. 16 is a time chart showing the operation of the printer according to the third embodiment of the present invention, and FIG. 17 is the third embodiment of the present invention. FIG. 18 is a second time chart for explaining the standby state in the third embodiment of the present invention. FIG. 18 is a first time chart for explaining the standby state in the embodiment.

  In this case, a printing condition setting processing unit (not shown) of the control circuit 161 (FIG. 9) performs a printing condition setting process, and sets a print standby state, that is, a print standby state.

  For this purpose, the temperature detection processing means of the printing condition setting processing means reads the detection voltage, refers to the temperature table shown in FIG. 14 recorded in the ROM (not shown) of the control circuit 161, and determines the detection voltage. The detected temperature Tb is detected by converting the detected temperature Tb to the detected temperature Tb representing the surface temperature of the conveyor belt 120 (FIG. 8).

  Subsequently, the temperature determination processing unit of the printing condition setting processing unit performs a temperature determination process to determine whether or not the detected temperature Tb is higher than a set temperature ψ1 (50 [° C.] in the present embodiment) as a threshold value. to decide. When the detected temperature Tb is higher than the set temperature ψ1, the remaining printing number calculation processing unit as the remaining printing amount calculation processing unit of the printing condition processing unit performs the remaining printing number calculation processing as the remaining printing amount calculation processing, and the remaining printing number Pr is calculated by reading the number of unprinted pages of the job currently being printed.

  Next, the standby determination processing means of the print condition setting processing means performs standby determination processing, and determines whether or not the remaining number of printed sheets Pr is larger than a threshold value Pth1 (5 sheets in the present embodiment). The threshold value Pth1 is determined based on the characteristics of the printer that is actually used.

  When the remaining number of printed sheets Pr is larger than the threshold value Pth1, the standby processing unit of the printing condition setting processing unit performs the standby process, does not perform the paper feeding operation as the medium supply operation by the paper feeding mechanism 136, and sets the time τ It waits to start the printing process as the image forming process until (in this embodiment, 20 seconds) elapses. In this way, the printer can be placed in a standby state and the printing process can be temporarily stopped.

  The temperature determination processing means determines whether the detected voltage is higher than 2.712 [V] when determining whether the detected temperature Tb is higher than the set temperature ψ1 based on the temperature table. The set temperature ψ1 is set to 50 ° C. in the present embodiment, but various values are taken depending on the characteristics of the toner used, and the fluidity of the toner is lowered as described above. In consideration of the temperature at which the charge amount increases or softens, the temperature is obtained and set in advance by experiments and recorded in the ROM.

  The set time τ is set to 20 seconds in the present embodiment, but is the time required for the temperature exceeding 50 ° C. to fall below 50 ° C., and the printer structure, cooling means ( For example, it depends on the presence or absence of a cooling fan device. The set time τ is set so that the temperature inside the printer does not rise when printing is performed intermittently at intervals of the set time τ in a high temperature environment.

  Thus, when the surface temperature of the conveyor belt 120 is lowered, the print start processing means of the print condition setting processing means performs the print start process, performs the paper feeding operation, starts the print process, and prints one page. I do. Then, as shown in FIG. 16, the print start processing means repeats the printing operation and determines whether or not printing of the remaining number of prints Pr has been completed. When the printing of the remaining number of prints Pr is completed, the print processing unit ends the process.

  On the other hand, when the remaining print number Pr is equal to or less than the threshold value Pth1, the print continuation processing unit of the print condition setting processing unit performs the print continuation process, prints the remaining print number Pr, repeats the printing operation, It is determined whether or not printing of the remaining number of prints Pr has been completed. When the printing of the remaining print number Pr is completed, the standby processing means performs the standby process as described above.

  In the standby state, the standby processing unit can immediately start the image forming process instead of placing the paper 121 in the medium storage box 137 so as not to reduce the printing throughput as the image forming throughput. The position, for example, the front end of the sheet 121 is placed at a standby position set immediately before the photo sensor 152. The standby processing means lowers the temperature inside the photosensitive drums 116Bk, 116Y, 116M, 116C and the printer by lowering the fixing control temperature of the fixing device 148 or turning off the heater of the fixing device 148. To do.

  In order to lower the fixing control temperature of the fixing device 148, the standby processing means turns off the fixing device motor control signal SG1 for a set time τ as shown in FIG. The time for turning off the signal SG2 is lengthened. In this case, since the heater power supply is kept on / off during the set time τ, the detected temperature Tb is lowered, but the heater continues to be energized intermittently. Therefore, the temperature inside the printer cannot be lowered rapidly.

  However, since the heater is controlled at a temperature close to the fixing control temperature of the fixing device 148 when the printing process is started after the set time τ has elapsed, the fixing device 148 immediately reaches the fixing control temperature. Therefore, the printing operation can be performed immediately.

  Note that the heater can be turned off instead of lowering the fixing control temperature of the fixing device 148. In this case, as shown in FIG. 18, the standby processing means turns off the fixing device motor control signal SG1 for a set time τ, and accordingly, the heater control signal SG2 is completely turned off. In this case, since the heater is turned off for the set time τ, the temperature inside the printer can be rapidly lowered. However, since the heater temperature is low when the printing process is started after the set time τ has elapsed, it takes time for the fixing device 148 to reach the fixing control temperature. Therefore, the printing operation cannot be performed immediately.

  In the standby process, whether the fixing control temperature of the fixing device 148 is lowered or the heater is turned off depends on the structural characteristics of the printer, the characteristics of the parts used, the image quality to be realized, and the like. It is selected appropriately.

  As described above, when the temperature of the conveyor belt 120 is detected and the detected temperature Tb is higher than the set temperature ψ1, the printing process is waited to start, so that the surface temperatures of the photosensitive drums 116Bk, 116Y, 116M, and 116C. And it can suppress that the temperature inside a printer becomes high.

  In the present embodiment, when the detected temperature Tb is higher than the set temperature ψ1, if the remaining print number Pr in the job being printed is equal to or less than the threshold value Pth1, the standby process is performed after the printing of the remaining print number Pr is completed. Thus, it is possible to shorten the waiting time until the operator finishes printing all the number of printed sheets of the job. Accordingly, it is possible to prevent the predetermined component from being excessively heated during printing, and to improve the printing throughput.

Next, a flowchart will be described.
Step S41: It is determined whether or not the detected temperature Tb is higher than the set temperature ψ1. If the detected temperature Tb is higher than the set temperature ψ1, the process proceeds to step S42. If the detected temperature Tb is equal to or lower than the set temperature ψ1, the process proceeds to step S47.
Step S42: It is determined whether or not the remaining number of printed sheets Pr is larger than the threshold value Pth1. If the remaining number of printed sheets Pr is larger than the threshold value Pth1, the process proceeds to step S45. If the remaining number of printed sheets Pr is equal to or smaller than the threshold value Pth1, the process proceeds to step S43.
Step S43 The remaining number of prints Pr is printed.
Step S44: It is determined whether printing of the remaining number of printed sheets Pr has been completed. If printing of the remaining number of prints Pr has been completed, the process proceeds to step S45, and if not, the process returns to step S43.
Step S45 The process waits without performing the paper feeding operation.
Step S46: It is determined whether the set time τ has elapsed. If the set time τ has elapsed, the process proceeds to step S47, and if not, the process returns to step S45.
Step S47 Paper feeding operation is performed.
Step S48 One page is printed.
Step S49: It is determined whether printing of the remaining number of prints Pr has been completed. If the printing of the remaining number of prints Pr has been completed, the process is terminated. If not, the process returns to step S41.

  In the present embodiment, the remaining number of prints Pr of the job currently being printed is calculated as the remaining print amount. However, as the remaining print amount, print data as in the first and second embodiments is calculated. The amount D can be calculated or the number of dots can be calculated. When printing is performed in a print mode such as N-up (for example, 2-up) in which a plurality of N pages are printed on one sheet, N-up can be calculated as one page.

  Next, a fourth embodiment of the present invention will be described. In addition, about the thing which has the same structure as the said 1st-3rd embodiment, the same code | symbol is provided and the effect of this embodiment is used about the effect of the invention by having the same structure.

  FIG. 19 is a flowchart showing the operation of the printer according to the fourth embodiment of the present invention.

  In the third embodiment, it is determined whether the remaining number of printed sheets Pr is larger than the threshold value Pth1 based on the job being printed. In the present embodiment, only the job being printed is determined. Instead, the determination is made based on the total number of pages of other spooled jobs.

  Therefore, the standby determination processing unit determines whether or not the remaining number of printed sheets Pr is larger than a threshold value Pth1 (5 sheets in the present embodiment).

When the remaining number of printed sheets Pr is larger than the threshold value Pth1, the standby processing unit includes the total number of printed sheets Pi and the remaining number of printed sheets Pr among the unprinted jobs spooled on the hard disk 240 (FIG. 11). Sum ΣP with
ΣP = Pi + Pr
It is determined whether or not there is at least one job having a threshold Pth1 or less.

  If there is at least one job for which the sum ΣP is less than or equal to the threshold value Pth1, the print continuation processing unit prints the remaining number of prints Pr of the job currently being printed and at least one job, and the remaining number of prints Pr and at least It is determined whether printing of one job is finished. When the printing of the remaining number of prints Pr and at least one job is completed, the standby processing unit performs the standby processing as described above.

  If there is no unprinted job in which the sum ΣP is less than or equal to the threshold value Pth1, the print continuation processing unit prints the remaining number of prints Pr of the job that is currently being printed. Determine whether printing is complete. When the printing of the remaining print number Pr is completed, the standby processing means performs the standby process as described above.

  As described above, in this embodiment, when there is at least one job in which the sum ΣP is equal to or less than the threshold value Pth1, the remaining number of prints Pr of the job currently being printed and the waiting after the printing of at least one job is completed. Since the processing is performed, it is possible not only to shorten the waiting time until the operator finishes printing all the number of prints of the job, but also the waiting time of the job of the operator who performs the next printing Can be shortened.

Next, a flowchart will be described.
Step S51: It is determined whether the detected temperature Tb is higher than the set temperature ψ1. If the detected temperature Tb is higher than the set temperature ψ1, the process proceeds to step S52. If the detected temperature Tb is equal to or lower than the set temperature ψ1, the process proceeds to step S60.
Step S52: It is determined whether or not the remaining number of printed sheets Pr is larger than the threshold value Pth1. If the remaining number of printed sheets Pr is larger than the threshold value Pth1, the process proceeds to step S58. If the remaining number of printed sheets Pr is equal to or smaller than the threshold value Pth1, the process proceeds to step S53.
Step S53: It is determined whether there is at least one job for which the sum ΣP is equal to or less than the threshold value Pth1. If there is at least one job for which the sum ΣP is less than or equal to the threshold value Pth1, the process proceeds to step S54, and if not, the process proceeds to step S56.
Step S54: The printing job and at least one job are printed.
Step S55: It is determined whether the remaining number of prints Pr and at least one job have been printed. If printing of the remaining number of prints Pr and at least one job has been completed, the process proceeds to step S58, and if not, the process returns to step S54.
Step S56 The remaining number of prints Pr is printed.
Step S57: It is determined whether printing of the remaining number of printed sheets Pr has been completed. If printing has ended, the process proceeds to step S58, and if printing has not ended, the process returns to step S56.
Step S58 The apparatus waits without performing the paper feeding operation.
Step S59: It is determined whether the set time τ has elapsed. If the set time τ has elapsed, the process proceeds to step S60, and if not, the process returns to step S58.
Step S60 Paper feeding operation is performed.
Step S61 Print one page.
Step S62: It is determined whether printing of the remaining number of printed sheets Pr has been completed. If the printing of the remaining number of prints Pr has been completed, the process is terminated. If not, the process returns to step S51.

  In each of the above-described embodiments, examples of applying to a printer as an image forming apparatus have been described. However, the present invention can be applied to a copying machine, a facsimile machine, a multifunction machine, and the like.

  The present invention is not limited to the above embodiments, and various modifications can be made based on the gist of the present invention, and they are not excluded from the scope of the present invention.

FIG. 2 is a block diagram illustrating a printer control device according to the first exemplary embodiment of the present invention. It is a 1st flowchart which shows operation | movement of the level detection part in the 1st Embodiment of this invention. It is a 2nd flowchart which shows operation | movement of the level detection part in the 1st Embodiment of this invention. It is a time chart which shows transition of head temperature in a 1st embodiment of the present invention. It is a block diagram showing the control apparatus of the printer in the 2nd Embodiment of this invention. It is a 1st flowchart which shows operation | movement of the level detection part in the 2nd Embodiment of this invention. It is a 2nd flowchart which shows operation | movement of the level detection part in the 2nd Embodiment of this invention. It is the schematic of the printer in the 3rd Embodiment of this invention. It is a 1st block diagram which shows the control apparatus of the printer in the 3rd Embodiment of this invention. It is a 2nd block diagram which shows the control apparatus of the printer in the 3rd Embodiment of this invention. It is a block diagram which shows the control circuit in the 3rd Embodiment of this invention. It is a figure which shows the format of the print job in the 3rd Embodiment of this invention. It is a block diagram of the temperature detection measurement circuit in the 3rd Embodiment of this invention. It is a figure which shows the temperature table in the 3rd Embodiment of this invention. 10 is a flowchart illustrating an operation of a printer according to a third embodiment of the present invention. It is a time chart which shows operation | movement of the printer in the 3rd Embodiment of this invention. It is a 1st time chart for demonstrating the standby state in the 3rd Embodiment of this invention. It is a 2nd time chart for demonstrating the standby state in the 3rd Embodiment of this invention. It is a flowchart which shows operation | movement of the printer in the 4th Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Print head 11 Head temperature detection part 15 Print speed determination part 16 Print pass frequency determination part 19 Print processing part 120 Conveyor belt 121 Paper 161 Control circuit 188 Temperature detection sensor

Claims (6)

(A) a recording unit that forms an image on a medium according to predetermined image data;
(B) a temperature detection unit for detecting the temperature of a predetermined component;
(C) printing condition setting processing means for setting printing conditions based on the detected temperature and the remaining printing amount;
(D) An image forming apparatus comprising: a print processing unit that performs printing based on the printing conditions.   The image forming apparatus according to claim 1, wherein the printing condition setting processing unit sets printing conditions based on the detected temperature, the remaining printing amount, and the printing duty.   The image forming apparatus according to claim 1, wherein the printing condition is an execution printing speed corresponding to the detected temperature and the remaining printing amount.   The image forming apparatus according to claim 1, wherein the printing condition is a number of printing passes corresponding to the detected temperature and the remaining printing amount.   The print condition setting processing unit continues printing of the remaining print amount when the detected temperature is higher than the set temperature or when the remaining print amount in a job being printed is equal to or less than a threshold value. Image forming apparatus.   The print condition setting processing unit is a case where the detected temperature is higher than the set temperature, and among the unprinted jobs, at least a job whose sum of the total print amount and the remaining print amount is equal to or less than a threshold value is included. The image forming apparatus according to claim 1, wherein when there is one, the remaining print amount of the job currently being printed and the printing of at least one job are continued.

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