JP4794969B2 - Ink jet printer heater control circuit and control method thereof, ink jet printer - Google Patents

Description

The present invention relates to a heater control circuit for an ink jet printer and a control method thereof, and more particularly, to a heater control circuit and a control method for an ink jet printer that drives a heater using a commercial AC power supply, and an ink jet equipped with the heater control circuit for the ink jet printer. Regarding printers .

  In an ink jet printer, a heater is used to fix ink on a recording medium such as recording paper. This heater is driven by a commercial AC power supply (hereinafter referred to as “commercial power supply”). Commercial power sources include a 100v system and a 200v system.

  2. Description of the Related Art Conventionally, there is an ink jet printer provided with a heater control circuit used for a 100v commercial power supply and a heater control circuit used for a 200v commercial power supply. In order to keep the amount of heat generated by the heater constant, the user has switched the heater control circuit to be used depending on whether the commercial power source is a 100v system or a 200v system.

  In addition, many techniques have been disclosed regarding the control of the heater.

  Patent Document 1 (Japanese Patent Application Laid-Open No. 2004-78146) discloses a current waveform of a commercial power supply so that the current waveform of the commercial power supply applied to the heater is not a waveform including a harmonic current but a waveform close to a sine wave. A heater control method for controlling the above is described.

  In this heater control method, the maximum electric power is supplied to the heater by making the current applied to the heater a waveform close to a sine wave.

  Japanese Patent Application Laid-Open No. 2003-255756 describes an image forming apparatus that reduces flicker generated by turning on and off a heater.

This image forming apparatus obtains a stable flicker reduction effect by changing the time from the zero cross point to turning on the heater according to the frequency or voltage of the commercial power source.
JP 2004-78146 A JP 2003-255756 A

  In the 100v system commercial power supply, the voltage has a value between 100v and 120v, and in the 200v system commercial power supply, the voltage has a value between 200v and 240v.

  Conventionally, a heater control circuit used in a 100v system commercial power supply is set to correspond to 110v which is a median value of 100v to 120v.

  For this reason, for example, when the actual voltage of the 100v commercial power supply is 100v, the heater is underheated, and when the actual voltage of the 100v commercial power is 120v, the heater is transient response. .

  Moreover, the heater control circuit used with a 200v type commercial power supply is set corresponding to 220v which is a median value of 200v to 240v.

  For this reason, for example, when the actual voltage of the 200v system commercial power supply is 200v, the heater seems to be underheated, and when the actual voltage of the 200v system commercial power supply is 240v, the heater becomes a transient response. .

  Therefore, when the actual voltage of the commercial power source is different from a preset value, the heater control circuit cannot properly control the heater.

  The heater control technology that has been disclosed to date has many countermeasures against noise such as countermeasures against harmonic currents and flickers that are generated when the heater is driven, and Patent Documents 1 and 2 also describe actual power supplies in 100v or 200v commercial power supplies. There is no description of a function that eliminates the excess or deficiency of the heating value of the heater due to the voltage difference.

  An object of the present invention is to provide a heater control device and a heater control method for an ink jet printer that can appropriately control the amount of heat generated by a heater according to the actual voltage of a commercial power source.

In order to achieve the above object, a heater control device for an ink jet printer according to the present invention includes a heater for fixing ink to a recording medium, a receiving unit that receives AC power, and an AC power received by the receiving unit. A control unit that controls the amount of heat generated by the heater, and the control unit includes a plurality of AC power supplies that can be received by the reception unit at a plurality of frequencies. A pulse width storage unit that associates and stores the reference signal width corresponding to each combination, and
A zero-cross signal having a pulse width corresponding to the width of the period less than the absolute value is smaller reference voltage than the maximum value of the voltage of the AC power supply of AC power source comprises a zero-crossing point the AC power supply voltage to accept by the accepting unit A generating unit for generating, a pulse width measuring unit for measuring the pulse width of the zero-cross signal generated by the generating unit, and a period detecting unit for detecting a cycle of the zero-cross signal generated by the generating unit; The frequency is calculated from the period detected by the period detection unit, the calculation result is the frequency of the zero cross signal, and the pulse based on the frequency of the zero cross signal and the pulse width of the zero cross signal. the frequency of the width of the signal serving as the reference stored in the width storage portion is stored in the frequency and the pulse width storing unit of the zero-cross signal Are obtained by selecting the first pulse width and the second pulse width in the order close to the pulse width of the zero-cross signal, and obtaining the first voltage and the second pulse width associated with the first pulse width. An associated second voltage, and a ratio of the difference between the pulse width and the second pulse width of the zero-cross signal and the difference between the first pulse width and the second pulse width. A value is calculated, a difference value between the second voltage and the first voltage and a value of the ratio are integrated to calculate a change amount of the voltage from the second voltage, and the change to the second voltage is calculated. added amount calculating a voltage corresponding to the pulse width of the zero-crossing signal, and a voltage calculating unit to the voltage of the AC power supply that receives the voltage at the receiving unit corresponding to the pulse width of the zero-crossing signal the obtained by the voltage calculation unit And a heater control unit for controlling the heating value of the heater based on the voltage of the flow source.

In addition, the heater control method for an ink jet printer of the present invention is a heater control method for an ink jet printer that controls an amount of heat generated by supplying an AC power to a heater for fixing ink on a recording medium. The printer has a pulse width storage unit that stores a plurality of voltages combined with a plurality of frequencies of the AC power supply that can be supplied, and associates and stores a reference signal width corresponding to each combination, and supplies the pulse width storage unit to the inkjet printer. generating for generating a zero-cross signal having absolute value is a pulse width corresponding to the width of the period below the lower reference voltage than the maximum value of the voltage of the AC power supply of the AC power source comprises a zero-crossing point the AC power supply voltage A pulse width measuring step for measuring the pulse width of the zero-cross signal; and A period detecting step of detecting a period of the signal, a step of computing the frequency from the period, the frequency determined by the step of calculating the frequency is the frequency of the zero-cross signal, the zero-cross signal and the frequency of the zero-cross signal Based on the pulse width, the frequency of the zero cross signal and the frequency stored in the pulse width storage unit are the same from the width of the reference signal stored in the pulse width storage unit. Selecting and acquiring a first pulse width and a second pulse width in order of closeness to the pulse width of the zero-cross signal; a first voltage associated with the first pulse width; and a second pulse width associated with the second pulse width. obtaining a second voltage, and the value of the difference between the pulse width and the second pulse width of the zero-cross signal, the first The second voltage is obtained by calculating a ratio value between the pulse width and the difference between the second pulse width and integrating the difference value between the second voltage and the first voltage and the ratio value. The amount of change in voltage from is calculated, the amount of change is added to the second voltage, the voltage corresponding to the pulse width of the zero-cross signal is calculated, and the voltage corresponding to the pulse width of the zero-cross signal is calculated. A calculation step for setting the voltage of the AC power source supplied to the ink jet printer, and a heater for controlling a heat generation amount of the heater based on the voltage of the AC power source supplied to the ink jet printer obtained by the calculation step Control steps.

  According to said invention, the actual voltage of AC power supply is detected based on the pulse width of a zero cross signal, and the period of AC power supply, and the emitted-heat amount of a heater is controlled based on the detected voltage.

  For this reason, it becomes possible to appropriately control the amount of heat generated by the heater according to the actual voltage of the commercial power supply.

  The pulse width of the zero cross signal changes according to the voltage and period (frequency) of the AC power supply. Furthermore, when the voltage and frequency of the AC power supply are determined, the pulse width of the zero cross signal is determined.

  For example, when the frequency of the AC power supply is constant, the pulse width of the zero cross signal becomes narrower as the voltage of the AC power supply increases. When the voltage of the AC power supply is constant, the pulse width of the zero cross signal becomes narrower as the frequency of the AC power supply increases.

  The frequency of the AC power source is obtained from the cycle of the AC power source.

  For this reason, it is possible to determine the voltage of the AC power source from the pulse width of the zero cross signal corresponding to the AC power source and the cycle of the AC power source.

  In this case, it is not necessary to directly measure the voltage of the AC power supply. Therefore, when a commercial power supply is used as the AC power supply, it is not necessary to use a special measuring instrument for measuring a large voltage such as 100v or 200v.

  A parameter storage unit is provided for storing a parameter for controlling the amount of heat generated by the heater used at the time of the voltage in association with the voltage of the AC power source. The parameter storage unit is referred to and detected. It is desirable to determine the parameter used at the time of voltage and control the heat generation amount of the heater using the determined parameter.

  According to the above invention, the parameter storage unit can manage the parameters for controlling the heat generation amount of the heater.

  Further, for each of a plurality of types of AC power supplies having different combinations of voltage and frequency, a pulse width storage unit that stores the voltage and frequency of the AC power supply and the pulse width of the zero cross signal corresponding to the AC power supply in association with each other. The frequency of the AC power supply is detected from the detected period, and the first pulse width and the second pulse width are calculated in the order closer to the measured pulse width from the pulse width associated with the frequency. It is desirable to select and detect the voltage of the AC power source based on the voltage associated with the first pulse width and the voltage associated with the second pulse width.

  According to the invention described above, it is possible to manage the relationship between the voltage and frequency of the AC power supply and the pulse width of the zero cross signal corresponding to the AC power supply using the pulse width storage unit.

  According to the above invention, the actual voltage of the AC power supply is detected based on the pulse width of the zero cross signal and the period of the AC power supply, and the heat generation amount of the heater is controlled based on the detected voltage. For this reason, it becomes possible to appropriately control the amount of heat generated by the heater according to the actual voltage of the commercial power supply.

  Hereinafter, a heater control circuit (hereinafter referred to as “heater control circuit”) of an ink jet printer according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram showing a heater control circuit according to an embodiment of the present invention. The heater control circuit is mounted on the ink jet printer.

  In FIG. 1, the heater control circuit includes a heater 1, an AC power supply receiving unit 2, an operation panel 3, and a control unit 4. The control unit 4 includes a zero cross signal generation unit 5, a pulse width counter 6, a cycle counter 7, and a heater control unit 8. The heater control unit 8 includes a memory 9, a nonvolatile memory 10, a program memory 11, and a CPU 12. The nonvolatile memory 10 includes a pulse width storage unit 10a. The program memory 11 includes a parameter storage unit 11a.

  The heater 1 generates heat and fixes the ink to a recording medium (not shown) such as recording paper.

  The AC power supply receiving unit 2 receives commercial power.

  The operation panel 3 receives input from the user.

  The control unit 4 controls the amount of heat generated by the heater 1 by supplying commercial power received by the AC power supply receiving unit 2 to the heater 1.

  The zero cross signal generator 5 detects the zero cross point of the commercial power received by the AC power receiver 2 and generates a zero cross signal corresponding to the commercial power.

  FIG. 2 is an explanatory diagram for explaining the operation of the zero-cross signal generator 5.

  Specifically, FIG. 2A is a waveform diagram showing the relationship between the voltage 201 of the commercial power supply and the reference voltage V1, and FIG. 2B is an enlarged view of part of FIG. FIG. 2C is a waveform diagram corresponding to FIG. 2B and showing a zero cross signal ZC in which a pulse is generated at each zero cross point.

  In FIG. 2A, the reference voltage V1 (for example, 5V) is set near 0V.

  The zero-cross signal generator 5 compares the voltage 201 with the reference voltage V1, and generates a zero-cross signal ZC that becomes “1” only during a period when the absolute value of the voltage 201 is lower than the reference voltage V1.

  As shown in FIGS. 2A to 2C, when the frequency of the commercial power source is constant, the pulse width of the zero cross signal ZC becomes narrower as the commercial power source voltage increases.

  FIG. 3 is also an explanatory diagram for explaining the operation of the zero-cross signal generator 5.

  Specifically, FIG. 3A is a waveform diagram showing the relationship between the voltage 201 of the commercial power supply and the reference voltage V1, and FIG. 3B is a zero cross signal ZC corresponding to FIG. FIG.

  As shown in FIGS. 3A and 3B, when the voltage of the AC power supply is constant, the pulse width of the zero-cross signal becomes narrower as the frequency of the AC power supply increases.

  FIG. 4 is a circuit diagram illustrating an example of the zero-cross signal generation unit 5.

  In FIG. 4, the zero-cross signal generation unit 5 includes an ACIN (Live) terminal 51, an ACIN (NEUTRAL) terminal 52, resistors R1 and R2, diodes D1 and D2, a photocoupler Q1, and an output terminal A. . Photocoupler Q1 includes a light emitting diode Q1a and a light receiving transistor Q1b.

  The light emitting diode Q1a is connected to the ACIN terminal 51 and the ACIN terminal 52. Commercial power is applied between the ACIN terminal 51 and the ACIN terminal 52. The voltage applied to the ACIN terminal 51 is the voltage 201 shown in FIGS.

  In the light receiving transistor Q1b, the emitter E is grounded to GND, and the collector C is connected to one end of the resistor R2 and the output terminal A. The other end of the resistor R2 is connected to the power supply VCC. The output of the output terminal A is the zero cross signal ZC shown in FIGS.

  When the voltage applied to the light emitting diode Q1a is large enough to generate light sufficient to turn on the light receiving transistor Q1b, that is, when the absolute value of the voltage of the commercial power supply is equal to or higher than the reference voltage V1, the output terminal A changes to A signal is output.

  When the voltage of the commercial power supply becomes small and the voltage applied to the light emitting diode Q1a does not generate light enough to turn on the light receiving transistor Q1b, that is, when the absolute value of the commercial power supply voltage is smaller than the reference voltage V1, the collector C The signal becomes high impedance, and a signal “1” is output from the output terminal A by the pull-up resistor R2 connected to the collector C. This “1” signal is a zero-cross signal.

  Thus, the zero cross signal generator 5 outputs “0” when the absolute value of the commercial power supply voltage is equal to or higher than the voltage (reference voltage V1) for turning on the light receiving transistor Q1b, and the absolute value of the commercial power supply voltage is received. When the voltage is lower than the voltage (reference voltage V1) for turning on the transistor Q1b, "1" (zero cross signal) is output.

  Returning to FIG. 1, the pulse width counter 6 measures the pulse width of the zero cross signal generated by the zero cross signal generator 5.

  The period counter 7 measures the period of the zero cross signal generated by the zero cross signal generation unit 5. Note that the period of the zero cross signal indicates the period of the commercial power supply corresponding to the zero cross signal. Therefore, the cycle counter 7 indirectly detects the cycle of the commercial power received by the AC power receiving unit 2.

  The heater control unit 8 detects the voltage of the commercial power source received by the AC power source reception unit 2 based on the pulse width measured by the pulse width counter 6 and the cycle detected by the cycle counter 7. The amount of heat generated by the heater 1 is controlled based on the detected voltage.

  The memory 9 is a working memory for the CPU 12.

  The nonvolatile memory 10 stores parameters for controlling the amount of heat generated by the heater 1 and includes a pulse width storage unit 10a.

  The pulse width storage unit 10a stores the voltage and frequency of the AC power supply and the pulse width of the zero cross signal corresponding to the AC power supply for each of a plurality of types of AC power supplies having different combinations of voltage and frequency. To do.

  FIG. 5 is an explanatory diagram showing an example of the pulse width storage unit 10a.

  In FIG. 5, the pulse width storage unit 10a stores the frequency 10a1 and voltage 10a2 of the AC power supply and the pulse width 10a3 of the zero cross signal corresponding to the AC power supply in association with each other.

  The pulse width 10a3 is a pulse width measured by the pulse width counter 6 when the AC power supply receiving unit 2 receives an AC power supply specified by the frequency 10a1 and the voltage 10a2.

  Returning to FIG. 1, the program memory 11 is a computer-readable recording medium. The program memory 11 stores a program that defines the operation of the heater control circuit. The program memory 11 includes a parameter storage unit 11a.

  The parameter storage unit 11a stores a parameter for controlling the amount of heat generated by the heater 1 used at the voltage in association with the voltage of the commercial power source.

  FIG. 6 is an explanatory diagram showing an example of the parameter storage unit 11a.

  In FIG. 6, the parameter storage unit 11a stores the commercial power supply voltage 11a1 and the parameter (Kr) 11a2 in association with each other.

  Returning to FIG. 1, the CPU 12 is an example of a heat generation amount control unit. The CPU 12 implements various functions by reading a program recorded in the program memory 11 and executing the read program.

  For example, the CPU 12 detects the voltage of the commercial power source based on the pulse width measured by the pulse width counter 6 and the cycle of the commercial power source detected by the cycle counter 7.

  Specifically, the CPU 12 first detects the frequency of the commercial power source from the period detected by the period counter 7.

  Subsequently, the CPU 12 selects a pulse width associated with the detected frequency from the pulse width storage unit 10a.

  Subsequently, the CPU 12 selects two pulse widths (“first pulse width” and “second pulse width”) in order from the selected pulse width in the order closer to the pulse width measured by the pulse width counter 6. Select.

  Subsequently, the CPU 12 selects a voltage associated with the first pulse width and a voltage associated with the second pulse width from the pulse width storage unit 10a.

  Subsequently, the CPU 12 detects the voltage of the commercial power supply based on the selected voltage.

  Further, the CPU 12 refers to the parameter storage unit 11a, determines a parameter Kr used at the detected voltage, and controls the amount of heat generated by the heater 1 using the determined parameter Kr.

  Specifically, first, the CPU 12 refers to the parameter storage unit 11a to determine a parameter Kr used at the detected voltage.

  Subsequently, the CPU 12 stores the determined parameter Kr in the nonvolatile memory 10.

  Subsequently, the CPU 12 controls the amount of heat generated by the heater 1 using the parameter Kr stored in the nonvolatile memory 10.

  FIG. 7 is a block diagram illustrating an example in which the CPU 12 controls the amount of heat generated by the heater 1 using the parameter Kr. In FIG. 7, the CPU 12 adjusts the time for applying the commercial power source to the heater 1 using the parameter Kr.

  In FIG. 7, the CPU 12 includes an input unit 12a, a calculation unit 12b, a calculation unit 12c, and an application time control unit 12d.

  The thermistor 13 is provided on the platen or paper guide and detects the temperature of the heater 1.

  The input unit 12a receives a command value Z indicating the designated temperature of the heater 1.

  The calculation unit 12b receives the command value Z from the input unit 12a, receives the temperature T of the heater 1 from the thermistor 13, calculates ZT, and outputs the calculation result X.

  The calculation unit 12c multiplies (X · Kr) the calculation result X and the parameter Kr stored in the nonvolatile memory 10 and outputs the calculation result A.

  The application time control unit 12d adjusts the time for applying the commercial power source to the heater 1 according to the calculation result A. For example, the application time control unit 12 d applies commercial power to the heater 1 for the time indicated by the calculation result A.

  Next, the operation will be described.

  FIG. 8 is a flowchart for explaining the calibration operation. In the calibration operation, data is written in the pulse width storage unit 10a.

  Hereinafter, the calibration operation will be described with reference to FIG.

  In step 801, the AC power supply accepting unit 2 accepts a 100 v / 50 Hz reference AC power supply, and the pulse width counter 6 measures the pulse width of the zero cross signal corresponding to the reference AC power supply.

  Specifically, first, the user connects a 100 v / 50 Hz reference AC power supply to the AC power supply receiving unit 2.

  Subsequently, the user notifies the CPU 12 of an input instruction to the effect that the 100 v / 50 Hz reference AC power has been input through the operation panel 3, and further instructs the CPU 12 to execute an instruction to perform calibration.

  When the AC power supply accepting unit 2 accepts a 100 v / 50 Hz reference AC power supply, the zero cross signal generating unit 5 generates a zero cross signal corresponding to the reference AC power supply.

  When the zero cross signal generator 5 generates a zero cross signal, the pulse width counter 6 measures the pulse width of the zero cross signal and provides the measurement result to the CPU 12.

  When the CPU 12 receives the execution instruction, the CPU 12 stores the 100 v / 50 Hz indicated in the input instruction and the pulse width provided from the pulse width counter 6 in the memory 9 in association with each other.

  When step 801 ends, step 802 is executed.

  In step 802, the reference AC power source is switched to 100 v / 60 Hz, and the CPU 12 receives an input instruction and an execution instruction indicating that the 100 AC / 60 Hz reference AC power source has been input. In accordance with these instructions, the CPU 12 stores 100 v / 60 Hz in association with the pulse width of the zero cross signal at that time in the memory 9.

  When step 802 ends, step 803 is executed.

  In step 803, the reference AC power supply is switched to 120 v / 50 Hz, and the CPU 12 receives an input instruction and an execution instruction indicating that the 120 AC / 50 Hz reference AC power supply has been input. In accordance with these instructions, the CPU 12 stores 120 v / 50 Hz in association with the pulse width of the zero cross signal at that time in the memory 9.

  When step 803 ends, step 804 is executed.

  In step 804, the reference AC power supply is switched to 120 v / 60 Hz, and the CPU 12 receives an input instruction indicating that a 120 v / 60 Hz reference AC power supply has been input and an execution instruction. In accordance with these instructions, the CPU 12 stores 120 v / 60 Hz and the pulse width of the zero cross signal at that time in the memory 9 in association with each other.

  When step 804 ends, step 805 is executed.

  In step 805, the reference AC power supply is switched to 200 v / 50 Hz, and the CPU 12 receives an input instruction and an execution instruction indicating that the 200 v / 50 Hz reference AC power supply has been input. In accordance with these instructions, the CPU 12 stores 200 v / 50 Hz in association with the pulse width of the zero cross signal at that time in the memory 9.

  When step 805 ends, step 806 is executed.

  In step 806, the reference AC power supply is switched to 200 v / 60 Hz, and the CPU 12 accepts an input instruction and an execution instruction indicating that the 200 v / 60 Hz reference AC power supply has been input. In accordance with these instructions, the CPU 12 stores 200 v / 60 Hz in association with the pulse width of the zero cross signal at that time in the memory 9.

  When step 806 ends, step 807 is executed.

  In step 807, the reference AC power source is switched to 240 v / 50 Hz, and the CPU 12 receives an input instruction and an execution instruction indicating that the 240 v / 50 Hz reference AC power source has been input. The CPU 12 stores 240 v / 50 Hz in association with the pulse width of the zero cross signal at that time in the memory 9 in accordance with these instructions.

  When step 807 ends, step 808 is executed.

  In step 808, the reference AC power source is switched to 240 v / 60 Hz, and the CPU 12 receives an input instruction and an execution instruction indicating that the 240 v / 60 Hz reference AC power source has been input. The CPU 12 stores 240 v / 60 Hz in association with the pulse width of the zero cross signal at that time in the memory 9 in accordance with these instructions.

  When step 808 ends, step 809 is executed.

  In step 809, the CPU 12 creates a table by collecting the data stored in the memory 9 in steps 801 to 808.

  When step 809 ends, step 810 is executed.

  In step 810, the CPU 12 stores the table in the pulse width storage unit 10a.

  As a result, even if elements such as photocouplers and diodes have variations in characteristics, the values when the photocouplers and diodes are used at the reference voltage and reference frequency are collected, so that variations in the elements themselves can be calibrated. .

  FIG. 9 is a flowchart for explaining an initial adjustment operation performed when an ink jet printer provided with the heater control circuit is installed at a customer.

  Hereinafter, the initial adjustment operation will be described with reference to FIG. In the following description, it is assumed that the pulse width storage unit 10a stores the data shown in FIG. 5, and the parameter storage unit 11a stores the data shown in FIG.

  When installing the inkjet printer at the customer, the user connects the customer's commercial power supply to the AC power supply accepting unit 2, and further gives an initial adjustment instruction to the CPU 12 for initial parameter adjustment via the operation panel 3. Instruct.

  When the AC power supply receiving unit 2 receives the customer's commercial power supply, the zero-cross signal generation unit 5 generates a zero-cross signal corresponding to the commercial power supply. When the zero cross signal generation unit 5 generates a zero cross signal, the period counter 7 executes step 901.

  In step 901, the cycle counter 7 measures the cycle of the zero cross signal and provides the measured cycle to the CPU 12. In the following, it is assumed that the measured cycle is 20 ms. Note that this period is not limited to 20 ms.

  When the zero cross signal generation unit 5 generates a zero cross signal, the pulse width counter 6 executes step 902.

  In step 902, the pulse width counter 6 measures the pulse width of the zero cross signal and provides the measured pulse width to the CPU 12. In the following, it is assumed that the measured pulse width is 4350 us. This pulse width is not limited to 4350 us.

  When the CPU 12 receives the period and the pulse width, the CPU 12 executes Step 903.

  In step 903, the CPU 12 stores the cycle and the pulse width in the memory 9, and then determines the rank of the pulse width.

  First, the CPU 12 detects the frequency of the commercial power supply from the cycle. Since the period is 20 ms, the CPU 12 detects that the frequency of the commercial power supply is 50 Hz.

  Subsequently, the CPU 12 selects a pulse width associated with the detected frequency from the pulse width storage unit 10a.

  Subsequently, the CPU 12 selects the first pulse width and the second pulse width from the selected pulse widths in the order closer to the pulse width measured by the pulse width counter 6. Note that the first pulse width is longer than the second pulse width.

  Since the measured pulse width is 4350 us, the CPU 12 selects 4500 us as the first pulse width and 4200 us as the second pulse width.

  When the CPU 12 selects the first pulse width and the second pulse width, the CPU 12 executes Step 904.

  In step 904, the CPU 12 calculates the voltage of the commercial power supply according to a calculation method stored in advance in the program memory 11.

  For example, the CPU 12 obtains a value B obtained by subtracting the second pulse width 4200 us from the first pulse width 4500 us, and obtains a value C obtained by subtracting the second pulse width 4200 us from the measured pulse width 4350 us.

  Subsequently, the CPU 12 reads from the pulse width storage unit 10a the voltage 240v associated with the second pulse width 4200us and the voltage 200v associated with the first pulse width 4500us.

  Subsequently, the CPU 12 calculates (240−200) × (C / B) +200 using the values B and C, the voltage 240 v, and the voltage 200 v, and calculates the calculation result (220 v) as the commercial power supply voltage value. To do.

  Note that the CPU 12 may use, for example, an average of the voltage associated with the first pulse width and the voltage associated with the second pulse width as the voltage value of the commercial power supply.

  After calculating the voltage of the commercial power supply, the CPU 12 executes Step 905.

  In step 905, the CPU 12 determines a parameter for controlling the amount of heat generated by the heater 1 using the parameter storage unit 11a and the calculated voltage of the commercial power source.

  For example, the CPU 12 reads a parameter associated with the calculated commercial power supply voltage 220v, that is, Kr = 20347, from the parameter storage unit 11a.

  If there is no parameter associated with the calculated commercial power supply voltage 220v, the CPU 12 may determine the parameter as follows.

  The CPU 12 selects the voltage closest to the calculated commercial power supply voltage from among the voltages stored in the parameter storage unit 11a, and reads out the parameters associated with the selected voltage from the parameter storage unit 11a. .

  In addition, the CPU 12 selects two voltages from the voltages stored in the parameter storage unit 11a in the order closer to the calculated commercial power supply voltage, and the two parameters associated with the selected voltages. May be read from the parameter storage unit 11a and the parameters may be determined by proportional calculation using the two parameters.

  When the CPU 12 determines the parameter, it executes Step 906.

  In step 906, the CPU 12 stores the determined parameter in the nonvolatile memory 10.

  Thereafter, the CPU 12 controls the amount of heat generated by the heater 1 using the parameter Kr stored in the nonvolatile memory 10.

  According to this embodiment, the CPU 12 detects the voltage of the commercial power supply based on the pulse width of the zero cross signal and the cycle of the commercial power supply, and controls the amount of heat generated by the heater 1 based on the detected voltage.

  For this reason, it becomes possible to appropriately control the amount of heat generated by the heater 1 in accordance with the actual voltage of the commercial power source.

  The pulse width of the zero cross signal changes according to the voltage and period (frequency) of the commercial power supply. Furthermore, when the voltage and frequency of the commercial power supply are determined, the pulse width of the zero cross signal is determined.

  For example, when the frequency of the commercial power source is constant, the pulse width of the zero cross signal becomes narrower as the commercial power source voltage increases. In addition, when the voltage of the commercial power source is constant, the pulse width of the zero cross signal becomes narrower as the frequency of the commercial power source increases.

  Further, the frequency of the commercial power source is obtained from the cycle of the commercial power source.

  For this reason, the voltage of the commercial power supply can be determined from the pulse width of the zero cross signal and the cycle of the commercial power supply.

  In this case, it is not necessary to directly measure the voltage of the commercial power source. Therefore, it is not necessary to use a special measuring instrument for measuring a large voltage such as 100v or 200v.

  In this embodiment, the CPU 12 refers to the parameter storage unit 11a, determines a parameter to be used at the detected voltage, and controls the heat generation amount of the heater 1 using the determined parameter.

  In this case, the parameter storage unit 11a can manage parameters for controlling the amount of heat generated by the heater 1.

  In the present embodiment, the CPU 12 detects the frequency of the commercial power supply from the detected cycle, refers to the pulse width storage unit 10a, and determines the measured pulse width from the pulse widths associated with the frequency. The first pulse width and the second pulse width are selected in the order close to. The CPU 12 detects the voltage of the commercial power supply based on the voltage associated with the first pulse width and the voltage associated with the second pulse width.

  In this case, it is possible to manage the relationship between the voltage and frequency of the AC power supply and the pulse width of the zero cross signal corresponding to the AC power supply using the pulse width storage unit 10a.

  In the embodiment described above, the illustrated configuration is merely an example, and the present invention is not limited to the configuration.

  For example, the data stored in the pulse width storage unit 10a is not limited to the data shown in FIG. 5, and the data stored in the parameter storage unit 11a is not limited to the data shown in FIG.

  Further, the zero cross signal generation unit 5 is not limited to that shown in FIG.

It is the block diagram which showed the heater control circuit of one Example of this invention. FIG. 6 is an explanatory diagram for explaining the operation of the zero-cross signal generation unit 5. FIG. 6 is an explanatory diagram for explaining the operation of the zero-cross signal generation unit 5. 3 is a circuit diagram illustrating an example of a zero-cross signal generation unit 5. FIG. It is explanatory drawing which showed an example of the pulse width storage part 10a. It is explanatory drawing which showed an example of the parameter storage part 11a. 3 is a block diagram illustrating an example of a circuit that controls the amount of heat generated by the heater 1. FIG. It is a flowchart for demonstrating a calibration operation | movement. 6 is a flowchart for explaining an initial adjustment operation.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Heater 2 AC power supply reception part 3 Operation panel 4 Control part 5 Zero cross signal generation part 51 ACIN
52 ACIN
6 Pulse width counter 7 Period counter 8 Heater control unit 9 Memory 10 Non-volatile memory 10a Pulse width storage unit 11 Program memory 11a Parameter storage unit 12 CPU
12a input unit 12b calculation unit 12c calculation unit 12d application time control unit 13 thermistor

Claims (6)

A heater for fixing ink on a recording medium, a receiving unit that receives an AC power supply, and a control unit that controls the amount of heat generated by the heater by supplying the AC power received by the receiving unit to the heater. In the heater control circuit of the inkjet printer including
The controller is
Combining a plurality of voltages with a plurality of frequencies of an AC power supply that can be received by the reception unit, and storing a pulse width storage unit in association with a reference signal width corresponding to each combination;
A zero-cross signal having a pulse width corresponding to the width of the period less than the absolute value is smaller reference voltage than the maximum value of the voltage of the AC power supply of AC power source comprises a zero-crossing point the AC power supply voltage to accept by the accepting unit A generating unit to generate;
A pulse width measurement unit for measuring the pulse width of the zero-cross signal generated by the generation unit;
A period detection unit that detects a period of the zero-cross signal generated by the generation unit;
Calculate the frequency from the period detected by the period detection unit, the frequency obtained by the calculation as the frequency of the zero cross signal , based on the frequency of the zero cross signal and the pulse width of the zero cross signal, From the width of the reference signal stored in the pulse width storage unit, the frequency of the zero cross signal and the frequency stored in the pulse width storage unit are the same, and the pulse width of the zero cross signal is the same. The first pulse width and the second pulse width are selected and acquired in close order, the first voltage associated with the first pulse width and the second voltage associated with the second pulse width are acquired, and the zero crossing Calculating a ratio value between a difference value between the pulse width and the second pulse width of the signal and a difference value between the first pulse width and the second pulse width; The amount of change in voltage from the second voltage is calculated by integrating the value of the difference from the first voltage and the ratio, and the pulse of the zero-cross signal is calculated by adding the amount of change to the second voltage. a voltage calculation unit that calculates a voltage corresponding to the width, and the voltage of the AC power supply that receives the voltage at the receiving unit corresponding to the pulse width of the zero-crossing signal,
A heater control circuit for an ink jet printer, comprising: a heater control unit that controls a heat generation amount of the heater based on the voltage of the AC power source obtained by the voltage calculation unit . In the heater control circuit of the inkjet printer according to claim 1,
The controller is
A parameter storage unit that stores a parameter for controlling the amount of heat generated by the heater for each voltage of the AC power supply that can be received by the reception unit;
The heater control unit acquires the parameters corresponding to the voltage of the alternating current power supply obtained by the voltage calculation unit from the parameter storage unit based on the voltage of the alternating current power supply obtained by the voltage calculation unit A heater control circuit for an ink jet printer, which controls the amount of heat generated by the heater using the acquired parameter. In an inkjet printer comprising a heater for fixing ink to a recording medium,
An ink jet printer comprising the heater control circuit of the ink jet printer according to claim 1. A heater control method for an ink jet printer that supplies an AC power to a heater for fixing ink to a recording medium to control a heat generation amount of the heater,
The inkjet printer includes a pulse width storage unit that combines a plurality of voltages with a plurality of frequencies of the alternating-current power supply that can be supplied and stores a reference signal width corresponding to each combination in association with each other.
Zero crossing having a pulse width corresponding to the width of the period in which the absolute value of the AC power supply voltage comprises zero-cross point of the AC power supplied to the ink jet printer is below the lower reference voltage than the maximum value of the voltage of the AC power source A generating step for generating a signal;
A pulse width measuring step for measuring the pulse width of the zero-cross signal;
A period detecting step for detecting a period of the zero cross signal;
Calculating a frequency from the period;
The frequency obtained by the step of calculating the frequency is set as the frequency of the zero cross signal, and the reference stored in the pulse width storage unit based on the frequency of the zero cross signal and the pulse width of the zero cross signal. The first pulse width and the second pulse width are selected in order of the frequency of the zero cross signal and the frequency stored in the pulse width storage unit being the same and closer to the pulse width of the zero cross signal. Step to get and
Obtaining a first voltage associated with the first pulse width and a second voltage associated with the second pulse width;
A value of a ratio between a difference value between the pulse width and the second pulse width of the zero-cross signal and a difference value between the first pulse width and the second pulse width is calculated, and the second voltage and the The amount of change in voltage from the second voltage is calculated by integrating the value of the difference from the first voltage and the value of the ratio, the amount of change is added to the second voltage, and the pulse width of the zero cross signal is calculated. And calculating the voltage corresponding to the pulse width of the zero cross signal as the voltage of the AC power source supplied to the inkjet printer ,
A heater control method for an ink jet printer, comprising: a heater control step for controlling a heat generation amount of the heater based on the voltage of the AC power source supplied to the ink jet printer obtained by the calculating step . The heater control method for an inkjet printer according to claim 4,
The inkjet printer further includes a parameter storage unit that stores parameters for controlling the amount of heat generated by the heater for each voltage of the AC power supply,
The heater control step includes
Referring to the parameter storage unit based on the voltage of the AC power supplied to the inkjet printer obtained by said computing step, said AC power supplied to the ink jet printer obtained by said computing step a parameter determining step of acquiring the parameters corresponding to the voltage,
A heater heat generation amount control step of controlling the heat generation amount of the heater using the acquired parameter. The heater control method for an inkjet printer according to claim 4 or 5,
Supply a reference AC power supply, detect the pulse width of the zero cross signal of the reference AC power supply, and store the pulse width in the pulse width storage unit in association with the frequency and voltage of the reference AC power supply A heater control method for an ink jet printer having steps.

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