JP2010128010A - Heating device for image forming apparatus and method therefor - Google Patents

Abstract

Provided is a technique for realizing temperature control in consideration of a thermal environment to be heated in temperature control in a fixing process.
The present invention provides an image forming apparatus having a fixing unit that thermally fixes toner supplied from a toner cartridge. The toner cartridge includes a cartridge thermal characteristic information storage unit that stores cartridge thermal characteristic information representing thermal characteristics of the toner cartridge. The image forming apparatus heats an apparatus thermal characteristic information storage unit that stores apparatus thermal characteristic information representing thermal characteristics of the image forming apparatus, a cartridge mounting unit configured to be detachable from a toner cartridge, and a fixing unit. A heating unit; a reading unit that reads cartridge thermal characteristic information from the toner cartridge; and a fixing temperature control unit that controls the heating unit according to the read cartridge thermal characteristic information and apparatus thermal characteristic information.
[Selection] Figure 11

Description

  The present invention relates to control of a fixing temperature of an image forming apparatus.

  Image formation by electrophotography generally includes a fixing process in which toner transferred to a printing paper or other fixed object is heated and the toner is thermally fixed to the fixed object. In the temperature control of the fixing process, paying attention to the fact that the thermal condition for fixing the toner fluctuates according to the thermal characteristics of the toner, the temperature control information unique to the toner is stored in the storage medium of the toner cartridge. A technique that can be used in an image forming apparatus has also been proposed (Patent Document 1).

However, the technique of Patent Document 1 is merely a technique for optimizing temperature control in a steady state in which attention is paid to a change in toner physical properties, which is a thermal condition for fixing the toner, and the thermal environment of the fixing roller to be heated. Sufficient studies have not been made on temperature control in consideration of (thermal characteristics of the toner cartridge and the printer main body).
JP 2002-148998 A

  The present invention has been completed in order to solve at least a part of the above-described problems, and an object of the present invention is to provide a technique for realizing temperature control in consideration of a thermal environment to be heated in temperature control in a fixing process. And

[Application Example 1]
An image forming apparatus having a fixing unit that thermally fixes toner supplied from a toner cartridge,
The toner cartridge has a cartridge thermal characteristic information storage unit that stores cartridge thermal characteristic information representing thermal characteristics of the toner cartridge;
The image forming apparatus includes:
An apparatus thermal characteristic information storage unit for storing apparatus thermal characteristic information representing thermal characteristics of the image forming apparatus;
A cartridge mounting portion configured to be detachable from the toner cartridge;
A heating unit for heating the fixing unit;
A reading unit for reading the cartridge thermal characteristic information from the toner cartridge;
A fixing temperature control unit for controlling the heating unit according to the read cartridge thermal characteristic information and the apparatus thermal characteristic information;
An image forming apparatus comprising:

  Since the image forming apparatus according to the application example 1 can control the heating unit according to the cartridge thermal characteristic information and the apparatus thermal characteristic information, temperature control suitable for the thermal environment to be heated can be realized.

[Application Example 2]
An image forming apparatus according to Application Example 1,
The apparatus thermal characteristic information includes apparatus heat capacity information indicating a heat capacity of the image forming apparatus,
The cartridge thermal characteristic information includes cartridge thermal capacity information indicating a thermal capacity of the toner cartridge,
The fixing temperature control unit is an image forming apparatus that operates a heat supply amount per unit time to the heating unit according to the cartridge heat capacity information and the apparatus heat capacity information.

  The image forming apparatus according to the application example 2 can operate the heat supply amount per unit time to the heating unit in accordance with the cartridge heat capacity information and the apparatus heat capacity information, so that the heat capacity of the apparatus and the heat capacity of the cartridge are taken into consideration. The response characteristic of temperature control can be improved. As an example of improving the response characteristics, for example, quick response can be realized while suppressing excess temperature.

[Application Example 3]
An image forming apparatus according to Application Example 2,
The fixing temperature control unit is an image forming apparatus that supplies a periodic on / off signal to the heating unit to operate the heat supply amount.

  The image forming apparatus according to the application example 3 can supply the periodic on / off signal to the heating unit to perform the operation of the heat supply amount, and thus can realize the continuous operation of the heat supply amount in real time. .

[Application Example 4]
An image forming apparatus according to application example 2 or 3,
The cartridge heat capacity information includes toner amount heat capacity information which is information representing a heat capacity according to the toner amount,
The image forming apparatus includes a toner remaining amount determining unit that determines a toner remaining amount in the toner cartridge,
The fixing temperature control unit is an image forming apparatus that determines a heat capacity of the toner cartridge according to the determined remaining toner amount and the toner amount heat capacity information.

  The image forming apparatus according to the application example 4 can determine the heat capacity of the toner cartridge in accordance with the determined remaining toner amount and the toner amount heat capacity information. Thus, temperature control suitable for the thermal environment around the fixing unit can be realized. The “toner remaining amount” is a value determined by the amount of toner used (for example, the toner remaining amount can be defined as a value obtained by subtracting the amount of toner used from the amount of toner when the cartridge is opened). It has a broad meaning including quantities that have a correlation.

[Application Example 5]
An image forming apparatus according to any one of Application Examples 1 to 4,
The fixing temperature control unit updates the cartridge thermal characteristic information before starting heating by the heating unit.

  The image forming apparatus according to Application Example 5 can update the cartridge thermal characteristic information before the heating unit starts heating. For example, the toner heat capacity is excessively decreased in the immediately preceding print job, and the cartridge heat capacity is decreased. However, excessive temperature is appropriately suppressed. As a result, quick response of temperature control is realized, and excessive elevation can be avoided with high reliability.

  The present invention can be realized in various forms other than those described above. For example, an image forming apparatus method, a temperature control method, a toner cartridge, and a computer program or a computer program product (for example, storing a computer) that realizes temperature control. It can be realized in various forms such as a storage medium.

  According to the present invention, in the temperature control in the fixing process, it is possible to realize temperature control in consideration of the thermal environment to be heated.

Next, embodiments of the present invention will be described in the following order based on examples.
A. Schematic configuration of an image forming apparatus in an embodiment of the present invention:
B. Temperature control of the image forming apparatus in the embodiment of the present invention:
C. Variation:

A. Schematic configuration of an image forming apparatus in an embodiment of the present invention:
FIG. 1 is a schematic cross-sectional view showing an internal configuration of a printer 1 (an example of an “image forming apparatus” recited in the claims) according to an embodiment of the present invention. In this embodiment, the printer 1 uses the light of a laser or a light emitting diode for photosensitivity, and forms an image with toners of C (cyan), M (magenta), Y (yellow), and K (black). Printer.

  The printer 1 includes a paper feeding unit 110, image forming units 120C, 120M, 120Y, and 120K for each color, a conveyance mechanism 130, a fixing unit 140, a belt cleaning mechanism 150, a control unit 200, a heater power supply 300, Is provided. The heater power supply 300 supplies power to a heater (described later) that controls the fixing temperature.

  The toner forming cartridges 171C, 171M, 171Y, and 171K for supplying the toners of the respective colors are mounted on the image forming units 120C, 120M, 120Y, and 120K for the respective colors. These four toner cartridges 171C, 171M, 171Y, and 171K are equipped with nonvolatile memories 172C, 172M, 172Y, and 172K, respectively.

  The paper feeding unit 110 includes a tray 112 that stores sheet materials 111 such as printing paper and OHP sheets, a pickup roller 113 that takes out the sheet materials 111 one by one, and a paper feeding mechanism 114 that supplies the sheet material 111 to the transport mechanism 130. .

  The conveyance mechanism 130 is a mechanism that conveys the sheet material 111 in order to the image forming units 120K, 120Y, 120M, and 120C of the respective colors. The transport mechanism 130 includes a driving roller 131 and a driven roller 132, and a belt 133 that is stretched between the driving roller 131 and the driven roller 132.

  FIG. 2 is an enlarged view showing the configuration of the fixing unit 140 in the embodiment of the present invention. The fixing unit 140 includes a fixing roller 142, a pressure roller 143 that presses the fixing roller 142, a heater 144 that heats the fixing roller 142 (an example of a “heating unit” described in claims), a thermistor 145, , A peeling claw 146 for peeling off the toner, a cleaner 147 for cleaning the surface of the fixing roller 142, a pair of conveying rollers 149 arranged on the downstream side of the fixing roller 142 in the sheet conveying direction, and a casing for housing these 141.

  The fixing roller 142 is formed in a cylindrical shape using, for example, an aluminum metal. Both ends (not shown) of the cylindrical shape in the axial direction are rotatably supported by the casing 141. The fixing roller 142 is rotationally driven in the arrow direction by a main motor (not shown). The fixing roller 142 is heated by the heater 144 so as to reach a preset fixing temperature.

  In this embodiment, the heater 144 is a halogen heater 144 (also simply referred to as “heater” in the present specification). The halogen heater 144 is disposed along the central axis inside the fixing roller 142. The halogen heater 144 is controlled by cutting off (on / off) the power supplied from the heater power supply 300. The surface temperature of the heated fixing roller 142 is measured by the thermistor 145.

B. Temperature control of the image forming apparatus in the embodiment of the present invention:
FIG. 3 is a control block diagram of temperature control of the image forming apparatus in the embodiment of the present invention. The fixing process is performed by passing a printing medium having toner adhered between the pressure roller 143 and the fixing roller 142 in a state where the surface temperature of the fixing roller 142 is set to a preset fixing temperature. The fixing temperature is set, for example, as a temperature suitable for melting the toner and fixing it on the print medium.

  The temperature of the fixing roller 142 is controlled by feeding back the surface temperature (temperature measurement value Tri) of the fixing roller 142 measured by the thermistor 145. Specifically, the control unit 200 controls the deviation δ, which is a difference between the preset fixing temperature target value Trt and the temperature measurement value Tri, to be small.

  The fixing temperature target value Trt is determined based on data read from the non-volatile memories 172C, 172M, 172Y, 172K included in the toner cartridges 171C, 171M, 171Y, 171K. Accordingly, the fixing temperature target value Trt suitable for the physical properties of the toner supplied from the toner cartridges 171C, 171M, 171Y, and 171K can be set. However, when the fixing temperatures suitable for the physical properties of the toner are excessively different from each other, it is preferable to limit the execution of printing and alert the user.

  In this embodiment, the control unit 200 controls the temperature of the fixing roller 142 based on a control rule set in consideration of the thermal environment of the fixing roller 142. The thermal environment of the fixing roller 142 is determined in consideration of the heat dissipation Qo1 to the printer 1 and the heat dissipation Qo2 to the toner cartridges 171C, 171M, 171Y, and 171K. The heat dissipation Qo1 to the printer 1 is estimated based on the data read from the memory 210. The heat dissipation Qo2 to the toner cartridges 171C, 171M, 171Y, 171K is estimated based on the data read from the nonvolatile memories 172C, 172M, 172Y, 172K.

  The control unit 200 outputs a duty command value (pulse width signal) to the heater 300 based on the control side thus set. The heater 300 outputs a heating current to the heater 144 in accordance with the duty command value input from the control unit 200.

  FIG. 4 is an explanatory diagram showing a method for calculating the printer heat capacity X as the thermal environment of the fixing roller. The printer heat capacity X can be calculated as the sum of the heat capacity A of the printer 1 and the heat capacity Bc, Bm, By, Bk of each of the four toner cartridges 171C, 171M, 171Y, 171K.

  The heat capacities Bc, Bm, By and Bk can be determined as follows according to the remaining amount of toner. Specifically, for example, the heat capacity Bc of the cyan toner cartridge 171C can be calculated as the sum of the heat capacity Cc of the container portion of the cartridge and the heat capacity Dc of the toner of the cartridge. The heat capacity Dc of the toner can be calculated as a product of a known specific heat capacity Dshc, which is a physical property of the toner, and the toner remaining amount Vc. The toner remaining amount Vc can be determined by various methods such as a toner agitation load inside the cartridge 171C, a light transmission amount during agitation, and a subtraction of the toner amount used for image formation.

  FIG. 5 is an explanatory diagram showing a graph G1 representing the relationship between the temperature and the heat amount when the supply target of the heat amount Qt has the respective heat capacities Ct1 and Ct2, and a graph G2 representing an equivalent relationship. The heat capacity Ct2 has a larger value than the heat capacity Ct1, and the temperature rise corresponding to the supply of heat is relatively gradual.

  On the other hand, the graph G2 shows the relationship between the voltage V and the charge Qe when the charge Qe supply target (for example, a capacitor) has the electrostatic capacity Ce1 and when the heat supply target has the heat capacity Ce2. As described above, an equivalent circuit can be formed by replacing the heat capacities of the printer 1 and the toner cartridges 171C, 171M, 171Y, and 171K with the electrostatic capacities of the capacitors.

  FIG. 6 is an explanatory diagram showing a transient thermal impedance equivalent circuit in which the fixing roller during preheating and its thermal environment are expressed as an equivalent electric circuit. The transient thermal impedance equivalent circuit is a circuit for facilitating analysis of a transient state of a thermal environment by replacing a heat flow (heat transfer) with a current. Since this transient thermal impedance equivalent circuit is for preheating, it is configured so that there is no heat transfer (heat radiation Qo3, FIG. 3) to the sheet material 111 such as printing paper.

  The heat flow in the transient thermal impedance equivalent circuit is as follows. The heater power supply 300 applies heating power to the heater 144. The heater 144 generates heat having a heat amount Qi per unit time. This heat raises the surface temperature of the fixing roller 142 and is dissipated around the fixing roller 142.

  The fixing roller 142 includes, for example, a metal pipe 142a formed of an aluminum alloy and a foamed resin body 142b. The foamed resin body 142b has a heat-resistant insulating layer (not shown) between the metal pipe 142a and a hole for storing the heater 144 is formed.

  Thus, the heat that raises the surface temperature of the fixing roller 142 is a value obtained by subtracting the heat radiated around the fixing roller 142 from the heat (Qi) generated by the heater 144. Therefore, in controlling the surface temperature of the fixing roller 142, it can be seen that the control performance can be improved by considering the thermal environment (heat radiation environment) of the fixing roller 142 (FIG. 3).

  The heat radiation from the fixing roller 142 is divided into a heat radiation Qo1 to the printer 1 and a heat radiation Qo2 that is a heat radiation to the cartridge group (toner cartridges 171C, 171M, 171Y, and 171K). The thermal equivalent circuit (thermal model) of the printer 1 is configured as a series circuit of a capacitor having a thermal capacity A (FIG. 4) and a thermal resistor having a resistance value Rb. The thermal equivalent circuit of the printer 1 is grounded to the ground potential Gr. The ground potential Gr is an equivalent potential corresponding to room temperature.

  Thermal resistance is a linear approximation of resistance to heat transfer in forms such as heat conduction, heat transfer, and heat radiation. Heat conduction is heat transfer caused by a continuous part or contact of an object. Heat transfer is heat transfer due to air flow (convection). Thermal radiation is heat transfer by transmission as electromagnetic waves.

  On the other hand, an equivalent circuit of the cartridge group includes capacitors of thermal capacities Bc, Bm, By, Bk (FIG. 4) of each of the four toner cartridges 171C, 171M, 171Y, 171K and resistance values Rc, Rm, Ry, Rk. It is comprised as a circuit which connected in parallel the series circuit of these thermal resistances. The heat capacities Bc, Bm, By, and Bk vary depending on the remaining amount of toner and the specifications of the toner cartridge container as described above. The equivalent circuit of the cartridge group is grounded to the ground potential Gr.

  FIG. 7 is an explanatory diagram showing a temperature gradient inside the fixing roller. This temperature gradient indicates a state when the surface temperature of the fixing roller reaches the fixing temperature target value Trt. A curve Qi1 shows a temperature gradient when the heat supply amount per unit time is relatively large (high heating rate setting). A curve Qi2 shows a temperature gradient when the heat supply amount per unit time is relatively small (low heating rate setting).

  FIG. 8 is an explanatory diagram showing the transient response characteristics of the fixing roller in relation to the heating rate in the comparative example. The heating rate means the rate of temperature rise at the heat supply rates Qi1 and Qi2 that are the amount of heat supplied to the fixing roller 142 per unit time. At the heat supply speeds Qi1 and Qi2, the surface temperature of the fixing roller 142 reaches the fixing temperature target value Trt at times t1 and t3, respectively.

  Thus, it can be seen that the startup time of the printer 1 (time until printing is possible) can be shortened by increasing the heat supply rate and increasing the heating rate. However, when the heat supply rate is increased, as described below, there is a problem that the overshoot at time t2 is increased.

  When the printer 1 is activated, the heater 144 generates heat having a heat amount Qi per unit time. This heat raises the surface temperature of the fixing roller 142 and causes the above-described temperature gradient in the fixing roller 142. The surface temperature of the fixing roller 142 is measured by the thermistor 145 as described above. This measured value is fed back to the control unit 200 (FIG. 3).

  When the temperature measurement value Tri on the surface of the fixing roller 142 reaches the fixing temperature target value Trt at time t1 (FIG. 8), the control unit 200 (FIG. 3) stops supplying the heating power. However, since a temperature gradient (FIG. 7) is generated inside the fixing roller 142, the heat transfer continues so that the temperature gradient becomes small even after the heating by the heater 144 is stopped. As described above, since the heat transfer to the surface of the fixing roller 142 continues even after the heating is stopped, the heat transfer after the heating is stopped causes overshoot.

  Since the overshoot occurs due to heat transfer that occurs so that the temperature gradient (FIG. 7) decreases, the overshoot increases as the temperature gradient increases. Specifically, for example, when the heater 144 generates heat of a heat amount Qi1 and a heat amount Qi2 (smaller than the heat amount Qi1) per unit time, the fixing roller 142 has the same surface temperature, but the fixing roller 142 has the same surface temperature. The temperature gradient (FIG. 7) inside 142 is different from the total heat amount of the fixing roller 142. As a result, when the heater 144 is heated with the heat quantity Qi1 per unit time, the heater 144 has a larger overshoot than when the heater 144 is heated with the heat quantity Qi2 per unit time.

  However, the inventor of the present application has found that it is preferable to take into account not only the heating rate but also the variation in the amount of heat released from the surface of the fixing roller 142 in the temperature control of the fixing roller 142. In other words, the inventor of the present application perceived the problem of heat supply to the surface of the fixing roller 142 as not simply a problem of the heat supply speed from the heater 144 but a problem of subtracting the heat release from the heat supply from the heater 144. Yes (Fig. 6).

  FIG. 9 is an explanatory diagram showing the state of the transient response characteristic of the fixing roller in relation to the toner remaining amount in the comparative example. Since the remaining amount of toner affects the heat capacity of the toner cartridges 171C, 171M, 171Y, and 171K (FIG. 4), it affects the thermal environment of the fixing roller 142. As a result, the transient response characteristic also changes according to the remaining amount of toner.

  Specifically, when the remaining amount of toner is low (toner remaining amount Tn_Lo) and immediately after the toner cartridge is mounted (toner remaining amount Tn_Ful), the surface temperature of the fixing roller 142 is the fixing temperature at times t1 and t3, respectively. The target value Trt is reached. Such a difference is caused by a difference in the thermal environment (FIG. 6).

  For example, the toner remaining amount Tn_Ful increases the heat capacity of the cartridge group (FIG. 6), and accordingly, the heat dissipation Qo2 also increases. On the other hand, since the heat dissipation Qo1 includes almost no variation factor, the thermal environment of the fixing roller 142 can be specified in consideration of the heat capacity of the cartridge group.

  As described above, even when the heater 144 supplies the same amount of heat, the heating rate is increased when the remaining amount of toner is small, and the heating rate is decreased when the remaining amount of toner is large. This is because the amount of heat supplied to the fixing roller 142 is affected by the heat radiation from the fixing roller 142. Therefore, FIGS. 8 and 9 are graphs showing similar characteristics when the remaining amount of toner and the heat supply speed are interchanged.

  The control system in the comparative example is set so that the overshoot is an allowable amount in a state where the remaining amount of toner is the minimum amount. As a result, the startup time can be shortened while limiting the maximum amount of overshoot that can occur.

  FIG. 10 is a functional block diagram showing a schematic configuration of the printer and the cartridge in the embodiment of the present invention. The printer 1 includes a control unit 200, a heater 144, a heater power source 300 (FIG. 1) that supplies heating power to the heater 144, motors 400 that drive driving components, a control program, and a heat capacity A (FIG. 4) and a communication interface 220 that controls a function as a communication interface with the cartridge 171C and the like.

  The cartridge 171C includes a non-volatile memory 172C that stores data such as a control program and toner remaining amount, an authentication circuit 174C that authenticates that the cartridge 171C can perform specific control (described later), and controls of these components. A communication control circuit 173C that controls a function as a communication interface with the printer 1. The other cartridges 171M, 171Y, and 171K have the same configuration as the cartridge 171C in this embodiment.

  FIG. 11 is a flowchart showing a routine of the printing process in the embodiment of the present invention. This process is a process that is started when the user presses the power button or the like of the printer 1 and is repeatedly executed until the user turns off the power. In step S100, the printer 1 is turned on. In step S200, the printer 1 starts communication with the four cartridges 171C, 171M, 171Y, and 171K. This communication is executed as part of the startup process in response to power-on of the printer 1.

  In step S300, the printer 1 executes an ID recognition process. The ID recognition process is a process for authenticating that the cartridge 171C can execute specific control (described later) by exchanging communication with the authentication circuit 174C of the cartridge 171C. In this process, if ID recognition is successful, the process proceeds to step S380, and if ID recognition fails, the process proceeds to step S390.

  In step S380, the printer 1 determines whether there is print data. The print data is transmitted from, for example, a PC (not shown) connected to the printer 1. If there is no print data, S380 is repeated and executed. On the other hand, if there is print data, the process proceeds to S400.

  In step S400, the printer 1 acquires thermal characteristic information from the cartridge 171C. In this embodiment, the thermal characteristic information is information used for determining the heat capacity Bc of the cartridge 171C. This information includes the heat capacity Cc of the container portion of the cartridge, the specific heat capacity Dshc of the toner, and the toner remaining amount Vc. The printer 1 can determine the heat capacity Bc of the cartridge 171C as the sum of the product of the specific heat capacity Dshc of the toner and the remaining toner amount Vc and the heat capacity Cc (FIG. 4). The heat capacities Bm, By, Bk of the cartridges 171M, 171Y, 171K are similarly determined according to the remaining amount of toner.

  In step S500, the printer 1 sets a thermal control law (optimum mode). Specifically, the setting of the heat control law is performed by determining the heating rate according to the thermal environment determined according to the remaining amount of toner of each of the four cartridges 171C, 171M, 171Y, and 171K. The thermal environment is determined according to the heat capacities of the cartridges 171C, 171M, 171Y, and 171K determined in step S400 and the heat capacity A of the printer 1. The determination of the heating rate may be performed, for example, using a table in which the thermal environment stored in the memory 210 is associated with the heating rate. The thermal environment at this time is calculated as the total thermal capacity X of the printer, which is the sum of the thermal capacities Bc, Bm, By, Bk of the cartridges 171C, 171M, 171Y, 171K and the thermal capacity A of the printer 1.

  FIG. 12 is an explanatory diagram showing a transient response state of the temperature control of the fixing roller in the embodiment of the present invention. A curve Opt indicates a response characteristic when authentication is successful. On the other hand, a curve Tn_Lo and a curve Slow indicate the response characteristics when the remaining amount of toner at the time of authentication failure is low and immediately after the toner cartridge is mounted. When the authentication is successful, the control rule is set according to the remaining amount of toner, so that the response characteristic is almost the same as that of the curve Opt regardless of the remaining amount of toner.

  Specifically, the control unit 200 controls the heater power supply 300 so that the heating rate is slow when the remaining amount of toner is low, and when the overall remaining amount of toner is high, the heating rate is increased. The heater power supply 300 is controlled. As a result, the temperature of the fixing roller 142 is controlled so as to absorb fluctuations in the thermal environment. For example, when the remaining amount of toner is small, the heating rate is not excessively increased even if the heat dissipation Qo2 (FIG. 6) is small. On the other hand, when the residual amount of toner is large, the heating rate is excessively decreased even if the heat dissipation Qo2 is large. There will be nothing.

  When such processing is completed and the thermal control law is set, temperature control is immediately started and the process proceeds to step S600. In this temperature control, the controller 200 transmits a pulse width modulation signal to the heater power supply 300, so that a continuous heat supply amount operation is performed in real time.

  In step S600, the printer 1 executes a printing process. When the printing process is completed, the process proceeds to step S700.

  In step S700, the printer 1 writes the remaining amount of toner in the nonvolatile memory 172C. In this embodiment, the toner remaining amount is determined by subtracting the toner usage determined based on the print content from the current toner remaining amount. As a result, the remaining amount of toner used for determining the next control rule can be stored in the nonvolatile memory 172C of the cartridge 171C. The process returns to step S380 in response to the completion of storage of the remaining amount of toner.

  On the other hand, when the ID authentication fails in step S300, the process proceeds to step S390. In step S390, as in step S380, it is determined whether there is print data. If it is determined that there is no print data, the process of S390 is repeated. On the other hand, if it is determined that there is print data, the process proceeds to step S510.

  In step S510, the printer 1 sets a thermal control law (latest mode). In the thermal control law (slowest mode), a pre-stored heating rate is set so that the overshoot amount is within an allowable range regardless of the amount of remaining toner. Thereby, even if ID authentication fails, the failure and deterioration of the printer 1 resulting from overshoot can be suppressed.

  In step S610, the printer 1 executes a printing process. This printing process is the same as the process when the ID authentication is successful. In response to the completion of the printing process, the process returns to step S390.

  As described above, this embodiment can realize temperature control suitable for the thermal environment of the fixing roller 142 to be heated, and thus can realize quick response while suppressing overshoot (over temperature). . Furthermore, in this embodiment, since this thermal environment also takes into account fluctuations according to the remaining amount of toner, appropriate temperature control can be realized regardless of the amount of remaining toner.

  In general operation, a plurality of print jobs are processed with a standby state (cooling state) interposed therebetween. When this embodiment is applied in such a case, the fixing roller 142 is heated from the standby state (cooling state) in the acquisition of thermal characteristic information (step S400) and the setting of the thermal control law (optimum mode) (step S500). Is executed each time the printer enters the printable state. Therefore, for example, even if the toner is excessively used in the immediately preceding print job and the heat capacity of the cartridge is reduced, the temperature excess is appropriately suppressed. Thereby, the quick response from a standby state is realizable.

C. Variation:
As mentioned above, although several embodiment of this invention was described, this invention is not limited to such embodiment at all, and implementation in various aspects is possible within the range which does not deviate from the summary. is there. In particular, elements other than the elements described in the independent claims in the constituent elements in each of the embodiments described above can be omitted as appropriate because they are additional elements. Furthermore, elements described in the independent claims can be appropriately replaced with elements not described in the independent claims within the scope disclosed in the present specification.

  Furthermore, in the above-described embodiments, not all of the above-described advantages and effects lead to the essential constituent elements of the present invention, and the present invention has a degree of freedom in design that can easily realize each of the above-described advantages and effects. As long as it achieves at least one advantage or effect.

C-1. First Modification: In the above-described embodiment, the thermal environment is taken into consideration in consideration of fluctuations according to the remaining amount of toner. For example, the cartridge heat capacity representing the heat capacity of the toner cartridge not including information representing the remaining amount of toner. You may comprise so that a thermal environment may be set using information. In this way, it is possible to set the thermal environment in consideration of fluctuations in the heat capacity of each toner cartridge (for example, fluctuations in the remaining amount of toner).

  However, in the configuration of the embodiment, the cartridge heat capacity can be determined according to the remaining amount of toner and the toner amount heat capacity information that is information indicating the heat capacity according to the toner amount, and therefore, it is caused by the fluctuation of the remaining amount of toner. Considering the variation of the heat capacity, temperature control suitable for the thermal environment around the fixing unit can be realized. The “toner remaining amount” is a value determined by the amount of toner used (for example, the toner remaining amount can be defined as a value obtained by subtracting the amount of toner used from the amount of toner when the cartridge is opened). It has a broad meaning including quantities that have a correlation.

C-2. Second Modification: In the above-described embodiment, the heating power supply is controlled using the pulse width modulation signal. However, the present invention is not limited to such control. For example, the sequence and voltage set in advance by sequence control It may be controlled by. However, the configuration of the embodiment (the operation of the heat supply amount by supplying a periodic on / off signal to the heating unit) has the advantage that the operation of the continuous heat supply amount can be realized in real time. Yes.

C-3. Third Modification: In the above-described embodiment, a color printer has been described as an example. However, the present invention can also be applied to a monochrome printer.

C-4. In the present embodiment, in the setting of the heat control, the heating rate is determined by a table in which the thermal environment stored in the memory 210 is associated with the heating rate. However, the present invention is not limited to this. The calculation formula for calculating the heating rate is stored in the memory 210 in advance, and values indicating the thermal environment such as the heat capacity of the printer 1, the remaining amount of toner, and the toner cartridge capacity are substituted into the calculation formula, and the heating is performed. The speed may be determined.

1 is a schematic cross-sectional view illustrating an internal configuration of a printer according to an embodiment of the present invention. FIG. 3 is an enlarged view showing a configuration of a fixing unit 140 in an embodiment of the present invention. FIG. 3 is a control block diagram of temperature control of the image forming apparatus in the embodiment of the present invention. FIG. 3 is an explanatory diagram illustrating a method for calculating a printer heat capacity X as a thermal environment of a fixing roller. Explanatory drawing which shows graph G2 showing the relationship equivalent to graph G1 showing the relationship between the temperature in each heat capacity, and calorie | heat amount. FIG. 4 is an explanatory diagram showing a transient thermal impedance equivalent circuit in which the fixing roller and its thermal environment during preheating are expressed as an equivalent electric circuit. FIG. 3 is an explanatory diagram showing a temperature gradient inside the fixing roller. Explanatory drawing which shows the mode of the transient response characteristic of a fixing roller in the relationship with the heating rate in a comparative example. FIG. 6 is an explanatory diagram illustrating a state of transient response characteristics of a fixing roller in relation to a toner remaining amount in a comparative example. FIG. 2 is a functional block diagram illustrating a schematic configuration of a printer and a cartridge in the embodiment. 6 is a flowchart illustrating a routine of print processing in the embodiment. FIG. 6 is an explanatory diagram illustrating a transient response state of the temperature control of the fixing roller in the embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Printer 110 ... Paper feed part 111 ... Sheet material 112 ... Tray 113 ... Pickup roller 114 ... Paper feed mechanism 120C, 120M, 120Y, 120K ... Image formation part 130 ... Conveyance mechanism 131 ... Drive roller 132 ... Driven roller 133 ... Belt DESCRIPTION OF SYMBOLS 140 ... Fixing part 141 ... Casing 142 ... Fixing roller 143 ... Pressure roller 144 ... Halogen heater 145 ... Thermistor 146 ... Peeling claw 147 ... Cleaner 149 ... Conveyance roller 150 ... Belt cleaning mechanism 171C, 171M, 171Y, 171K ... Toner cartridge 172C ... Non-volatile memory 173C ... Communication control circuit 174C ... Authentication circuit 200 ... Control unit 210 ... Memory 220 ... Communication interface 300 ... Power supply device 300 ... Heater power supply 400 ... Motors

Claims (7)

An image forming apparatus having a fixing unit that thermally fixes toner supplied from a toner cartridge,
The toner cartridge has a cartridge thermal characteristic information storage unit that stores cartridge thermal characteristic information representing thermal characteristics of the toner cartridge;
The image forming apparatus includes:
An apparatus thermal characteristic information storage unit for storing apparatus thermal characteristic information representing thermal characteristics of the image forming apparatus;
A cartridge mounting portion configured to be detachable from the toner cartridge;
A heating unit for heating the fixing unit;
A reading unit for reading the cartridge thermal characteristic information from the toner cartridge;
A fixing temperature control unit for controlling the heating unit according to the read cartridge thermal characteristic information and the apparatus thermal characteristic information;
An image forming apparatus comprising: The image forming apparatus according to claim 1,
The apparatus thermal characteristic information includes apparatus heat capacity information indicating a heat capacity of the image forming apparatus,
The cartridge thermal characteristic information includes cartridge thermal capacity information indicating a thermal capacity of the toner cartridge,
The fixing temperature control unit is an image forming apparatus that operates a heat supply amount per unit time to the heating unit according to the cartridge heat capacity information and the apparatus heat capacity information. The image forming apparatus according to claim 2,
The fixing temperature control unit is an image forming apparatus that supplies a periodic on / off signal to the heating unit to operate the heat supply amount. The image forming apparatus according to claim 2, wherein
The cartridge heat capacity information includes toner amount heat capacity information which is information representing a heat capacity according to the toner amount,
The image forming apparatus includes a toner remaining amount determining unit that determines a toner remaining amount in the toner cartridge,
The fixing temperature control unit is an image forming apparatus that determines a heat capacity of the toner cartridge according to the determined remaining toner amount and the toner amount heat capacity information. The image forming apparatus according to any one of claims 1 to 4,
The fixing temperature control unit updates the cartridge thermal characteristic information before starting heating by the heating unit. A toner cartridge for supplying toner to an image forming apparatus,
A cartridge thermal characteristic information storage unit for storing cartridge thermal characteristic information representing thermal characteristics of the toner cartridge;
An interface circuit for outputting the cartridge thermal characteristic information in response to a request from the image forming apparatus;
With
The image forming apparatus includes an apparatus thermal characteristic information storage unit that stores apparatus thermal characteristic information that represents thermal characteristics of the image forming apparatus, a cartridge mounting unit configured to be detachable from the toner cartridge, and the fixing unit. A heating unit for heating the cartridge, a reading unit for reading the cartridge thermal characteristic information from the toner cartridge, and a fixing temperature for controlling the heating unit according to the read cartridge thermal characteristic information and the apparatus thermal characteristic information A toner cartridge comprising: a control unit; A computer program stored in a storage medium of a toner cartridge that supplies toner to an image forming apparatus, and causing the image forming apparatus to perform temperature control,
The image forming apparatus includes an apparatus thermal characteristic information storage unit that stores apparatus thermal characteristic information that represents thermal characteristics of the image forming apparatus, a cartridge mounting unit configured to be detachable from the toner cartridge, and the fixing unit. A heating unit that heats the cartridge, and a fixing temperature control unit that controls the heating unit according to the cartridge thermal characteristic information and the apparatus thermal characteristic information,
The computer program is
A function of reading out the cartridge thermal characteristic information from a toner cartridge including a cartridge thermal characteristic information storing unit that stores cartridge thermal characteristic information representing a thermal characteristic of the toner cartridge;
A function of controlling the heating unit according to the cartridge thermal characteristic information and the apparatus thermal characteristic information;
A computer program including a program for causing the image forming apparatus to realize the above.

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