JP2011059490A - Fixing temperature control device and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To shorten a warm-up period and save power for a heating roller of an image forming apparatus. <P>SOLUTION: A main heating part H1 performs heating at the heart of the center of a heating roller body 35 of the image forming apparatus. A sub-heating part H2 heats the end of the heating roller body 35. A temperature control unit 33 performs temperature rise control of the main heating part H1 and the sub-heating part H2 on the basis of temperature at the center and the end of the heating roller body. The temperature control unit 33 sets polygonal line characteristics to be constituted by connecting between fixable temperature on the low temperature side and fixable temperature on the high temperature side at the end of the heating roller 35 by a plurality of temperature characteristics from the one with small tilt, and when end temperature of the heating roller body 35 reaches temperature on the polygonal line characteristics corresponding to heating starting temperature, the temperature control unit discriminates that the end of the heating roller body reaches the fixable temperature. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a fixing temperature control device and an image forming apparatus, and is mounted on an image forming apparatus such as a copying machine using toner, a printer, a facsimile machine, or a digital multi-function peripheral (MFP) having these functions. The present invention relates to a suitable fixing temperature control device and an improvement of the image forming apparatus equipped with the same.

  Conventionally, this type of image forming apparatus forms a latent image on the surface of a rotating photoconductor based on image data read from a document, forms a toner image from the latent image with toner supplied from a toner cassette, and rotates the photosensitive drum. The toner image is transferred to the paper by conveying the paper between the body and the pressure roller disposed on the body, and the paper is passed between the heating roller and the pressure roller to heat and fix the transfer toner. A configuration for discharging paper is well known.

  In order to control the heating roller efficiently and uniformly, the heating roller is not shown in the figure, but in the long heating roller body, a main heater that heats around the central portion, and both ends are centered. Built-in sub-heater for heating.

  Moreover, in the vicinity of the heating roller, there is a central temperature detector that detects the temperature of the central portion in a non-contact state with respect to the heating roller, and an end temperature that detects the temperature of the end portion in contact with the heating roller. And a temperature control of the main heater and the sub-heater so that the heating roller reaches a fixing possible temperature (fixing stable temperature) based on the detected temperatures from the central temperature detector and the end temperature detecting unit. ing.

  In this type of image forming apparatus, generally, the period from the start of heating the heating roller to the predetermined fixable temperature is referred to as a warm-up period.

  Further, in the image forming apparatus, when heating is started for the next printing request from a state in which the heating roller is warm, the temperature rise is steeper in the central portion and the end portion of the heating roller. Since it is possible to determine that fixing is possible even when the end temperature of the heating roller is low to some extent, a correction formula for obtaining a fixable temperature corresponding to the heating start temperature of the sub-heater is set. When the temperature is reached, it is determined that fixing is possible.

  For example, as shown in FIG. 4, a primary correction equation A for obtaining a fixable temperature for each temperature between the heating start temperature at the end of the heating roller corresponding to a normal temperature equivalent temperature of 24 ° C. and a fixable upper limit temperature of 150 ° C. is set to 24 When starting the warm-up from ℃, when the end temperature of the heating roller is raised to 110 ℃, it is determined that the fixable temperature has been reached (warm-up completed), and when starting the warm-up from 65 ℃, the temperature is raised to 120 ℃ At that time, it was determined that the fixing temperature was reached (warm-up completed), and then the temperature was controlled to continue to the upper limit temperature for fixing.

  The horizontal axis in FIG. 4 is the detected temperature at the start of heating at the end of the heating roller, and the vertical axis in FIG. 4 is the fixable temperature corresponding to the detected temperature at the end of heating at the end of the heating roller. The detected temperature after the completion of warm-up in the central part is also shown (the same applies hereinafter).

  By the way, as a general known example of this type, there is a correction method for a temperature detection non-contact temperature sensor for a fixing device and a temperature control method for the fixing device in Japanese Patent Application Laid-Open No. 2001-242743 (Patent Document 1).

JP 2001-242743 A

  However, in the above-described prior art, when the heating roller is reheated, the temperature of the end of the heating roller is warmed by using one primary correction formula A until the fixing roller reaches a fixing maximum temperature of 150 ° C. from the normal temperature equivalent temperature of 24 ° C. Since the completion of the update was determined, only a rough determination was made for the individual start temperatures from the normal temperature equivalent temperature of 24 ° C. to the fixable upper limit temperature of 150 ° C., which shortened the warm-up period and reduced power consumption. There is room.

  In particular, the TEC (standard power consumption) measurement method in Energy Star, which is an energy saving standard, has a demand for shortening the warm-up period and reducing power consumption when a printing request is generated from a state where the apparatus is warm.

  Therefore, as a result of intensive observation and examination of the temperature at the start of heating of the heating roller and the fixable temperature in the image forming apparatus, the present inventor has made it possible to shorten the warm-up period and save power by setting the above correction formula finely. The present invention has been completed by paying attention to the point that it is easy to achieve.

  SUMMARY An advantage of some aspects of the invention is that it provides a fixing temperature control device for an image forming apparatus capable of shortening a warm-up period and saving power, and the image forming apparatus.

  In order to solve such a problem, a fixing temperature control device according to a first aspect of the present invention includes a heating roller main body disposed in an image forming apparatus and a heating roller built in the heating roller main body, and heating the central portion. A main heating unit, a sub-heating unit built in the heating roller main body for heating around this end, a central temperature detection unit for detecting the temperature of the central heating roller body, and a temperature at the end of the heating roller main body And a temperature control unit for controlling the temperature of the main heating unit and the sub-heating unit based on the detected temperatures of the central temperature detection unit and the end temperature detection unit. Is a temperature characteristic in which the fixable temperature rises between the low-temperature-side fixable temperature and the high-temperature-side fixable temperature at the end portion of the heating roller body corresponding to the heating start temperature of the end portion of the heating roller body. When a polygonal line characteristic formed by connecting a plurality of temperature characteristics with a small inclination is set, and the end temperature of the heating roller body reaches a temperature on the polygonal line characteristic corresponding to the heating start temperature, the end of the heating roller body It has a function of determining that the fixing temperature has been reached.

  A fixing temperature control apparatus according to a second aspect of the present invention has a configuration in which the polygonal line characteristic composed of two continuous temperature characteristics is set in the temperature control unit.

  According to a third aspect of the present invention, there is provided a fixing temperature control apparatus, wherein the temperature control unit is provided with a fixing lower limit temperature at the end of the heating roller body as a fixing temperature on the low temperature side and a heating roller with a fixing possible temperature on the high temperature side. The upper limit temperature at which the main body can be fixed is used, and the polygonal line characteristic is set between them.

  In the fixing temperature control apparatus according to claim 4 of the present invention, when at least the sub-heating unit is heated up and then reheated within a predetermined period, the temperature control unit reaches a fixing temperature based on the broken line characteristics. It has the structure which discriminate | determines.

  An image forming apparatus according to a fifth aspect of the present invention includes the fixing temperature control apparatus according to any one of the first to fourth aspects, and an image image forming unit that forms an image based on the image data.

  In such a fixing temperature control apparatus according to claim 1 of the present invention, the heating start temperature at the end portion of the heating roller body is between the fixing temperature at the low temperature side and the fixing temperature at the high temperature side at the end portion of the heating roller body. The temperature at which the fixable temperature rises and the temperature at the end of the heating roller body corresponds to the heating start temperature on the basis of the polygonal line characteristic that is connected by multiple temperature characteristics from the one with a small inclination. When the temperature reaches this temperature, the temperature control unit determines that the end of the heat roller body has reached the fixable temperature, so it can respond to each heating start temperature, shorten the warm-up period, and save power become.

  In the fixing temperature control apparatus according to the second aspect of the present invention, since the polygonal line characteristic composed of two continuous temperature characteristics is set in the temperature control unit, the setting of the polygonal line characteristic is simplified, and the warmth is further increased. The up period can be shortened and power can be saved.

  In the fixing temperature control device according to the third aspect of the present invention, the fixing possible lower limit temperature at the end of the heating roller main body is set as the fixing temperature on the low temperature side, and the fixing at the end of the heating roller main body is possible as the fixing possible temperature on the high temperature side. Since an upper limit temperature is used and the polygonal line characteristic between them is set in the temperature control unit, it is possible to accurately determine the fixable temperature as well as shortening the warm-up period and saving power.

  In the fixing temperature control apparatus according to claim 4 of the present invention, when at least the sub-heating unit is heated up and then reheated within a predetermined period, the temperature control unit reaches the fixing possible temperature based on the broken line characteristic. Therefore, when reheating within a predetermined period, the warm-up period can be shortened and power can be saved more reliably.

1 is a schematic block diagram showing an embodiment of a fixing temperature control device according to the present invention together with an image forming apparatus. 1 is a main part configuration diagram showing an internal configuration of an image forming apparatus according to the present invention. It is a figure explaining the principal part of the fixing temperature control apparatus which concerns on this invention. It is a figure explaining operation | movement of this invention and the conventional fixing temperature control apparatus.

  Embodiments of a fixing temperature control device and an image forming apparatus according to the present invention will be described below with reference to the drawings.

  The fixing temperature control device of the present invention will be described in the course of describing the image forming apparatus according to the present invention.

  FIG. 1 is a schematic block diagram showing an embodiment of an image forming apparatus including a fixing temperature control apparatus according to the present invention, and FIG. 2 is a main part configuration diagram for explaining an internal configuration of the image forming apparatus of FIG.

  In FIG. 1, the image forming apparatus A includes an image reading unit 3, a storage unit 5, an operation panel unit 7, a printing device 9, and a communication unit 11 connected to the main control unit 1 as a center. For example, a multifunction device. The image forming apparatus A has other constituent elements than these, but is not a main part of the present invention, and thus description and illustration thereof are omitted. The function of the main control unit 1 will be described later.

  As shown in FIG. 2, the image reading unit 3 is disposed on the upper part of the main body case 13 under the control of the main control unit 1. The image reading unit 3 optically reads an image from a document and performs electronic processing such as filtering. This is a known scanner that generates a print job, and the generated image data is sequentially stored in the storage unit 5 for each page of the document.

  A storage unit 5 in FIG. 1 is a readable / writable non-volatile memory that stores image data from the image reading unit 3 or the communication unit 11 and correction formulas described later, such as a hard disk (HDD), under the control of the main control unit 1. It is.

  As shown in FIG. 2, the operation panel unit 7 serves as a well-known, for example, liquid crystal display display unit disposed on the upper portion of the main body case 13 and a touch switch type input unit, and controls the main control unit 1. The display unit is a display unit that displays an operation state, various data, and the like in the image forming apparatus A, and an operation unit that receives an operation instruction input of the device A.

  As shown in FIG. 2, the printing apparatus 9 in FIG. 1 is controlled by the main control unit 1, and a paper feed stage 15 on which paper is set and a primary paper feed from the paper feed stage 15 are conveyed. A registration roller 17 for secondary paper feeding at a predetermined interval, a rotating photoreceptor 21 on which a toner image is formed by toner from a toner cassette 19 based on image data read from the storage unit 5, and secondary paper feeding A pressure roller 23 disposed in pressure contact with the rotary photoconductor 21 to transfer a toner image onto the paper sheet, and a heating roller 25 and a pressure roller 27 located downstream of the rotary photoconductor 21 and the pressure roller 23. And a fixing unit 29 for fixing the transferred toner image, for example, a monochrome or color image forming unit.

  As shown in FIG. 1, the printing device 9 includes a fixing temperature control device 31, which will be described in detail later.

  The communication unit 11 has a function of transmitting / receiving image data and the like to / from an external image forming apparatus (not shown) under the control of the main control unit 1.

  The main control unit 1 includes a CPU, a ROM that stores a startup program for the CPU, a working RAM, and the like. The image reading unit 3, the storage unit 5, the operation panel unit 7, the input / output unit 13, and printing are performed according to the operation program. The image forming apparatus has a function of controlling the apparatus 9 and the communication unit 11, transferring image data read from the image reading unit 3 and stored in the storage unit 5 to the printing device 9 and performing print control (image formation control).

  Next, the above-described fixing temperature control apparatus of the present invention will be described.

  As shown in FIG. 3, the fixing temperature control device 31 according to the present invention includes a heating roller 25, a central temperature detection unit S <b> 1, an end temperature detection unit S <b> 2, and a temperature control unit 33.

  The heating roller 25 is a long and cylindrical heating roller body 35 that is rotatably supported directly or indirectly on the body case 13 (not shown in FIG. 3), and the inside of the heating roller body 35. The main heating part H1 is disposed in the central part in the axial direction and heats the central part of the heating roller body 35, and is incorporated in both ends in the axial direction inside the heating roller body 35 and sandwiching the central part. And a sub-heating unit H2 that heats around both ends of the heating roller body 35.

  Note that the pressure roller 27 having the same axial dimension as the heating roller 25 is in contact with the heating roller 25, but the illustration thereof is omitted in FIG.

  The main heating part H1 and the sub-heating part H2 are composed of heater lamps such as halogen heaters, for example, and are heated by driving power applied from the power supply part 37 via the switch parts SW1 and SW2.

  The power supply unit 37 is a known unit that heats the main heating unit H1 and the sub-heating unit H2 by applying a DC or AC drive power source.

  The switch units SW1 and SW2 are mechanical or electronic switches that are on / off controlled by the temperature control unit 33, as will be described later, and drive power is applied from the power source unit 37 to the main heating unit H1 and the sub heating unit H2 during the on control. And has a function of stopping the heating of the main heating unit H1 and the sub-heating unit H2 by cutting off the driving power from the power source unit 37 during the off control.

  The central temperature detection unit S1 is disposed at a slight distance from the outer periphery of the central portion of the heating roller 25, and is a non-contact type temperature sensor including a thermistor or the like that detects the temperature of the central portion of the heating roller 25 in a non-contact state with the central portion. The end temperature detection unit S2 is a contact type temperature sensor that is disposed so as to contact the outer periphery of the end of the heating roller 25 and includes a thermistor or the like that detects the end temperature of the heating roller 25 in a contact state. The detection signal is also output to the temperature control unit 33.

  The temperature control unit 33 controls the temperature of the main heating unit H1 and the sub heating unit H2 up to the upper limit temperature at which fixing is possible in conjunction with the ON operation of the main power source (not shown), and the central temperature. Based on detection signals from the detection unit S1 and the end temperature detection unit S2, the switch units SW1 and SW2 are controlled to be turned off when the temperature exceeds the fixable upper limit temperature, and the switch when the temperature exceeds the fixable upper limit temperature. The units SW1 and SW2 are turned on, and the temperature at the center and end of the heating roller 25 is stably controlled to the maximum fixable temperature.

  When reheating the main heating unit H1 and the sub-heating unit H2 while the heating roller 25 is warmed, the temperature control unit 33 controls the switch units SW1 and SW2 to be on and can be fixed by a correction formula described later. It has a function to discriminate.

  The state in which the heating roller 25 is warmed is a sleep mode in which the main power is turned off or the operation panel unit 7 described above is not operated for several minutes and the power to the parts other than those necessary for restarting is shut off. After the transition to, the state in which the main heating part H1 and the sub-heating part H2 are reheated for a predetermined period, for example, within a few minutes to 30 minutes, refers to a mode in which the main power is turned on or the sleep mode is shifted to the normal mode. Therefore, a form of reheating them can be considered.

  The temperature control unit 33 is a temperature characteristic of the fixable temperature corresponding to the heating start temperature of the end portion of the heating roller body 35 between the lower limit temperature and the upper limit temperature of fixing at the end portion of the heating roller body 35. When the temperature of the end of the heating roller main body 35 reaches the temperature on the polygonal line characteristic corresponding to the heating start temperature, the heating roller main body 35 is set. It has a function of discriminating that the end of the toner has reached the fixing possible temperature.

  That is, as shown in FIG. 4 described above, the temperature control unit 33 has a fixable temperature of 110 ° C. to 115 ° C. corresponding to the heating start temperature from 24 ° C. to 65 ° C. corresponding to the normal temperature at the end of the heating roller body 35. The obtained primary correction formula B and the primary correction formula C for obtaining the fixable temperature of 115 ° C. to 150 ° C. corresponding to the heating start temperature from 65 ° C. to the fixable upper limit temperature of 150 ° C. are continuously connected. A polygonal line characteristic is preset.

  When the temperature control unit 33 warms up the heating roller body 35 (heating roller 25) from 24 ° C., the temperature at the end of the heating roller body 35 reaches 110 ° C. When the temperature at the fixing portion reaches 110 ° C. (warm-up completion) In the case of warming up from 65 ° C., it is determined that the fixable temperature has been reached (warm-up completed) when the temperature is raised to 115 ° C., and then the main heating unit H1 and the sub-heating unit H2 are continuously set to the fixable upper limit temperature It has a function to control the temperature rise.

  Next, an example of the operation of the above-described fixing temperature control device of the present invention will be briefly described.

  For example, when starting a day of work, when the user turns on the main power supply of the image forming apparatus A and starts a printing operation, the temperature control unit 33 controls the switch units SW1 and SW2 to turn on, thereby heating the main unit. The temperature of the part H1 and the sub-heating part H2 is controlled to the upper limit temperature where fixing is possible, and the printing operation is ensured.

  Thereafter, after the main power is turned off or the mode is changed to the sleep mode, the main power unit H1 and the sub heating unit H2 are operated while the main roller is turned on or the normal mode is changed while the heating roller 25 is warmed. The temperature control unit 33 refers to the polygonal line characteristic composed of the above-described primary correction equations B and C, and the temperature of the end part of the heating roller body 35 is a temperature on the polygonal line characteristic corresponding to the heating start temperature. Is reached, it is determined that the end of the heating roller main body 35 has reached the fixable temperature, and the operation of the printing apparatus 9 is ensured.

  For example, if the heating roller 25 is warmed at 65 ° C., the temperature control unit 33 performs reheating control on the main heating unit H1 and the sub heating unit H2, and the central temperature detection unit S1 and the end temperature detection unit. If it is determined based on the detection signal from S2 that the temperature at the end of the heating roller main body 35 has reached the fixable temperature 115 ° C., it is determined that the fixable temperature has been reached.

  Therefore, in the conventional configuration, if the heating start temperature of the end portion of the heating roller main body 35 is 65 ° C., the fixable temperature is 120 ° C. However, in the configuration of the present invention, it can be determined that the fixing is possible at 115 ° C. The period until completion of the upload is shortened by “about 1 second”. The shortening of “1 second” is a significant shortening of the warm-up period, and the accompanying power saving is also significant.

  As described above, the fixing temperature control device of the present invention includes the heating roller main body 35 disposed in the image forming apparatus, the main heating unit H1 that is built in the heating roller main body 35 and that heats the central portion, and the heating roller. A sub-heating unit H2 that is built in the main body 35 and that heats around this end, a central temperature detection unit S1 that detects the temperature of the central part of the heating roller main body, and an end that detects the temperature of the end of the heating roller main body 35 And a temperature control unit 33 that controls the temperature of the main heating unit H1 and the sub-heating unit H2 based on the detected temperatures of the central temperature detection unit S1 and the end temperature detection unit S2. Yes.

  In addition, the temperature control unit 33 is a temperature at which the fixable temperature rises between the lower limit temperature at which fixing is possible at the end of the heating roller body 35 and the upper limit temperature at which fixing is possible, corresponding to the heating start temperature at the end of the heating roller body 35. When a polygonal line characteristic connecting two temperature characteristics from a characteristic having a small inclination is set, and the temperature at the end of the heating roller body 35 reaches a temperature on the polygonal line characteristic corresponding to the heating start temperature, the heating is performed. It has a function of discriminating that the end of the roller body has reached the fixable temperature.

  Therefore, in the fixing temperature control device of the present invention, the time point at which it is determined that the end of the heating roller 25 has reached the fixable temperature is accurate, and the warm-up period is shortened and optimized. Power saving is also possible.

  Furthermore, since the polygonal line characteristic composed of two continuous temperature characteristics is set in the temperature control unit 33, the setting of the polygonal line characteristic is simplified, the operation is speeded up, and the warm-up period is further increased. Shortening and power saving are possible.

  However, the fixing temperature control device of the present invention is not limited to the polygonal line characteristic composed of two continuous temperature characteristics, and the present invention can be realized by using a polygonal line characteristic in which a plurality of temperature characteristics having different inclinations are continued from the one having a small inclination. The object of the invention can be achieved.

  Furthermore, in the fixing temperature control device of the present invention, the temperature is not limited to the configuration in which the polygonal line characteristic connecting between the lower limit temperature at which heat fixing is possible and the upper limit temperature at which fixing is possible is set. Alternatively, a setting may be made in which a polygonal line characteristic is connected between a predetermined fixing temperature on the low temperature side and fixing capability on the high temperature side.

  Moreover, in the fixing temperature control device of the present invention, the main heating is performed in a state where the heating roller 25 is warmed, for example, within a few minutes to three minutes after the main power supply is turned off or after entering the sleep mode. When reheating the part H1 and the sub-heating part H2, especially the sub-heating part H2, it is not limited to the configuration that determines that fixing is possible based on the broken line characteristics, but at least within a predetermined period after the temperature of the sub-heating part H2 is raised once There is an advantage that the warm-up period can be shortened and the power can be saved more reliably when reheating is performed.

  In the image forming apparatus A of the present invention equipped with the above-described fixing temperature control device according to the present invention, the same effect as that of the fixing temperature control device can be obtained.

1 Main control unit 3 Image reading unit 5 Storage unit 7 Operation panel unit (display unit, input unit)
DESCRIPTION OF SYMBOLS 9 Printing apparatus 11 Communication part 13 Main body case 15 Paper feed stage 17 Registration roller 21 Rotating photoconductor 23, 27 Pressure roller 25 Heating roller 29 Fixing part 31 Fixing temperature control apparatus 33 Temperature control part 35 Heating roller main body 37 Power supply part A Image Forming device (multifunction machine)
H1 Main heating part H2 Sub heating part SW1, SW2 Switch part

Claims (5)

A heating roller body disposed in the image forming apparatus;
A main heating part that is built in the heating roller body and heats around the central part;
A sub-heating unit that is built in the heating roller body and that heats around this end,
A central temperature detector for detecting the temperature of the central portion of the heating roller body;
An end temperature detection unit for detecting the end temperature of the heating roller body;
A temperature control unit that controls the temperature of the main heating unit and the sub heating unit based on the detected temperatures of the central temperature detection unit and the end temperature detection unit;
Comprising
The temperature control unit increases the fixable temperature between the low-temperature-side fixable temperature and the high-temperature-side fixable temperature at the end portion of the heating roller body corresponding to the heating start temperature of the heating roller body end portion. A polygonal line characteristic formed by connecting a plurality of temperature characteristics to a temperature characteristic having a small inclination is set, and an end temperature of the heating roller body reaches a temperature on the polygonal line characteristic corresponding to the heating start temperature. A fixing temperature control device that determines that the end of the heating roller main body has reached the fixable temperature. The fixing temperature control device according to claim 1, wherein the temperature control unit is configured to set the polygonal line characteristic including two continuous temperature characteristics. The temperature control unit uses the lower limit fixable temperature at the end of the heating roller body as the fixable temperature on the low temperature side, and uses the upper limit fixable temperature at the end of the heating roller body as the fixable temperature on the high temperature side. The fixing temperature control device according to claim 1, wherein the broken line characteristic is set between the two. The temperature control unit determines that the fixable temperature has been reached based on the broken line characteristics when at least the sub-heating unit is heated up and reheated within a predetermined period. The fixing temperature control device described. 5. An image forming apparatus comprising: the fixing temperature control apparatus according to claim 1; and an image image forming unit that forms an image based on image data.

Images