JP2006183882A - Peltier element driving device and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a Peltier element driving device detecting a current flowing to a Peltier element by connecting a current detecting resistance in series to the Peltier element, and monitoring the current flowing to the Peltier element, and an image forming device equipped with the Peltier element driving device. <P>SOLUTION: The Peltier element driving device has the Peltier element 4, a Peltier element driving DC power unit 3, a switching means 9 for switching the driving voltage by PWM, and timer counters 5 for counting PWM output time. The timer counters 5 are counted when the Peltier element driving power is ON-OFF, and a PWM duty of the Peltier element driving voltage is gradually changed to gradually increase and decrease driving voltage time. The current detecting resistance 6 for detecting the current flowing to the Peltier element 4 is added to detect the current flowing to the Peltier element 4. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a Peltier element driving device that drives a Peltier element used as a cooling device, and an image forming apparatus including the same.

Conventionally, in a Peltier element driving apparatus that drives a Peltier element, power is supplied to the Peltier element by a constant voltage or PWM.
When the Peltier element driving device is configured in the image forming apparatus, the power supply unit of the image forming apparatus is used. The DC constant voltage generated by the power supply unit is supplied to the Peltier element as it is or PWM is applied by a switching element such as an FET. Note that there are Patent Documents 1 to 3 as prior documents.
Japanese Patent Laid-Open No. 11-289111 JP 2000-324692 A Japanese Patent Laid-Open No. 2002-357952

By the way, when the ON / OFF control of the Peltier element is performed, if the temperature difference between the heat generating surface and the heat absorbing surface of the Peltier element is abruptly given, there is a disadvantage that the life of the Peltier element itself is shortened. Therefore, when the Peltier element is turned on (started up), the applied voltage applied from the Peltier element driving device is varied in steps of 0 to several volts to gradually increase the voltage applied to the Peltier element, At the time of turning off (at the time of falling), the applied voltage applied to the Peltier element from the Peltier element driving device can be varied from the rated voltage in several volt steps and gradually lowered to 0 volt, so that the life of the Peltier element However, the temperature difference between the heat generating surface and the heat absorbing surface of the Peltier element is given over time without shortening. At this time, the applied voltage is PWM driven, and the duty is gradually increased from 0% to 100%. Further, a method of changing the duty from 100% to 0% gradually is adopted.
However, since the current consumption of the Peltier element varies depending on the usage environment, etc., when the Peltier element driving device is configured using the power supply unit of the image forming apparatus, the current capacity of the power supply unit exceeds the current capacity of the Peltier element driving device. There was a risk.
SUMMARY An advantage of some aspects of the invention is that it provides a Peltier element driving apparatus capable of controlling the power consumption of a Peltier element to a predetermined level, and an image forming apparatus including such a Peltier element driving apparatus.

In order to achieve the above object, the invention described in claim 1 comprises a DC power supply device for driving a Peltier element, and switching means for switching a drive voltage of the DC power supply device, and when the Peltier element is turned on. The supply voltage for supplying the drive voltage to the Peltier element is gradually lengthened, and the supply voltage for supplying the drive voltage to the Peltier element is gradually shortened when the Peltier element is turned off. In a Peltier device driving apparatus that performs pulse width modulation, a current detection unit that detects a current flowing through the Peltier device, and a control that controls an on / off cycle of the switching unit based on a detection current detected by the current detection unit And a Peltier element driving device.
The invention according to claim 2 is characterized in that the control means comprises an A / D converter for A / D converting the detection current of the current detection means.
The invention according to claim 3 is characterized in that the control means comprises a comparator for comparing the detection current of the current detection means with a predetermined reference value.
According to a fourth aspect of the invention, there is provided an average power consumption setting means for setting an average power consumption of the Peltier element, and the control means turns on the switching means based on setting data of the average power consumption setting means. 4. The Peltier device driving device according to claim 1, wherein the Peltier device driving device controls an off cycle.
According to a fifth aspect of the present invention, there is provided a variable DC power supply device that supplies a drive voltage to the Peltier element, and when the Peltier element is turned on, the drive voltage supplied from the variable DC power supply device to the Peltier element is gradually increased. Current detecting means for detecting a current flowing in the Peltier element in a Peltier element driving device that controls the driving voltage supplied from the variable DC power supply to the Peltier element to be gradually lowered when the Peltier element is turned off. And a control means for controlling an output voltage output from the variable DC power supply device based on a detection current detected by the current detection means.

The invention according to claim 6 is characterized in that the control means includes an A / D converter for A / D converting the detection current of the current detection means.
The invention according to claim 7 is characterized in that the control means comprises a comparator for comparing the detection current of the current detection means with a predetermined reference value.
The invention according to claim 8 further includes maximum supply current setting means for setting a maximum supply current to be supplied to the Peltier element, and the control means varies the output voltage of the variable DC power supply device, thereby 8. The Peltier element driving device according to claim 5, wherein the current value of the Peltier element is controlled so as to always become a set current value.
According to a ninth aspect of the present invention, there is provided a humidity detection means that is disposed in the vicinity of the part to be measured and detects the humidity in the vicinity of the part to be measured, and the control means is based on a detection result of the humidity detection means. The Peltier element driving device according to any one of claims 1 to 8, which controls driving of the Peltier element.
The invention according to claim 10 is provided with a temperature detection means that is arranged in the vicinity of the part to be measured and detects the temperature in the vicinity of the part to be measured, and the control means is based on a detection result of the temperature detection part. The Peltier element driving device according to any one of claims 1 to 9, which controls driving of the Peltier element.
The invention described in claim 11 includes a fan for sending air to the Peltier element, and fan driving voltage supply means for supplying a driving voltage to the fan, and the driving voltage of the fan is controlled by the variable DC power supply. The Peltier element driving device according to claim 9 or 10, wherein the Peltier element driving device is changed according to an output voltage.

According to a twelfth aspect of the present invention, there is provided an image forming apparatus using the Peltier device driving device according to any one of the first to eleventh aspects for temperature control of a laser diode.
According to a thirteenth aspect of the present invention, there is provided an image forming apparatus using the Peltier element driving device according to any one of the first to eleventh aspects for controlling humidity of the photosensitive drum.
According to a fourteenth aspect of the present invention, there is provided an image forming apparatus that uses the Peltier element driving device according to any one of the first to eleventh aspects for humidity control for dehumidifying a sheet.
According to a fifteenth aspect of the present invention, there is provided an image forming apparatus using the Peltier device driving device according to any one of the first to eleventh aspects for temperature control of an optical sensor.
According to a sixteenth aspect of the present invention, there is provided an image forming apparatus using the Peltier element driving device according to any one of the first to eleventh aspects for temperature control of a toner adhesion amount detection sensor.
According to a seventeenth aspect of the present invention, there is provided an image forming apparatus that uses the Peltier element driving device according to any one of the first to eleventh aspects for temperature control of a color misregistration detection sensor.

  According to the Peltier drive device of the present invention, the current detection means is inserted in series with the Peltier element, and the drive of the Peltier element is controlled based on the detection result of the current detection means. Fluctuations in power consumption can be suppressed. Therefore, when the Peltier driving device of the present invention is applied to the image forming apparatus, it is possible to prevent the current capacity from being exceeded in the power supply unit of the image forming apparatus due to the power consumption fluctuation of the Peltier element.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a block diagram showing a configuration of an average power control system using a Peltier device driving apparatus according to a first embodiment of the present invention.
The average power control system shown in FIG. 1 includes a Peltier element control unit 1, a power supply device 3, and a Peltier element 4.
The Peltier element control unit 1 includes a CPU 2, a plurality of timer counters 5, 5... 5, a current detection resistor 6, an A / D converter 7, a setting register 8, and a switching drive element 9.
In the Peltier element control unit 1 configured as described above, when the Peltier element 4 is PWM-driven, a PWM control signal is output from the CPU 2 to the switching drive element 9. The switch drive element 9 turns on / off the DC voltage for the Peltier element 4 supplied from the power supply device 3 by the PWM control signal from the CPU 2 and supplies the drive voltage obtained by applying PWM to the Peltier element 4.
For example, when the power is turned on, the CPU 2 outputs the PWM signal to the switching drive element 9 while varying the pulse width so that the supply period for supplying the drive voltage from the power supply device 3 to the Peltier element 4 is gradually increased. For this reason, the CPU 2 is provided with timer counters 5, 5... 5 that count the output time of the PWM signal of each pulse width. In this case, the number N of timer counters 5 is provided by the number of output stages depending on the pulse width. In this way, when the power is turned on, the CPU 2 manages the output time of the PWM signal of each pulse width by the timer counter 5 so as not to give a sudden temperature difference between the heat generating surface and the heat absorbing surface of the Peltier element 4. The lifetime of the Peltier element 4 is prevented from being shortened.
Similarly, when the power is turned off (when the power is turned off), the CPU 2 applies PWM to the switching drive element 9 while varying the pulse width so that the supply period for supplying the drive voltage from the power supply device 3 to the Peltier element 4 is gradually shortened. By outputting a signal, the lifetime of the Peltier element 4 is prevented from being shortened by preventing a sudden temperature difference between the heat generation surface and the heat absorption surface of the Peltier element 4.
In addition, in the Peltier control unit 1 according to the first embodiment, the current detection resistor 6 for current detection of the Peltier element 4 is connected in series with the Peltier element 4. Here, if the resistance value R of the current detection resistor 6 and the value of the current flowing through the current detection resistor 6 are Ip, the detection output (detection voltage) of the current detection resistor 6 can be represented by resistance value R × current value Ip. . The AD converter 7 converts the detected voltage into a digital value of several bits. The setting register 8 is a register for setting a target average power value.
The CPU 2 calculates the average power by the product of the detected Ip (current value), Va (drive voltage), and Ton / T (PWM pulse width (on width) / pulse period) so that the target average power is obtained. The pulse width of PWM is controlled. Thereby, the power consumption fluctuation of the Peltier device is suppressed depending on the use environment.

FIG. 2 is a diagram showing the supply timing of the driving voltage to the Peltier device when the Peltier device driving apparatus according to the first embodiment is turned on.
2A shows a drive trigger signal for driving the Peltier element, FIG. 2B shows a drive voltage supplied to the Peltier element 4, FIG. 2C shows a current of the Peltier element, and FIG. Each average power is shown. In this case, the current value of the Peltier element 4 shown in (c) varies depending on the temperature difference between the heat generating surface and the heat absorbing surface of the Peltier element 4.
Therefore, in the first embodiment, the drive voltage supplied from the power supply device 3 is PWM-controlled by the switching drive element 9 so that the average power shown in (d) falls below a certain value, thereby changing the duty. Like to do.
Note that the CPU 2 always controls the average power to be a threshold value when the trigger signal TRG is on, regardless of when the power is turned on.
FIG. 3 is a block diagram showing a configuration of an average power control system using the Peltier device driving apparatus according to the second embodiment. Note that the same parts as those in FIG.
The Peltier device control unit of the average power control system shown in FIG. 3 uses the comparator 10 instead of the A / D converter 7 used in the Peltier device control unit shown in FIG. Like to do.
In this case, the detection voltage value of the current detection resistor 6 is input to the minus terminal of the differential input terminal of the comparator 10. On the other hand, the fixed voltage value Vref is input in advance to the differential input plus terminal of the comparator 10.
The fixed voltage value Vref can be determined by Vref = R (resistance value) × Ipms (set current value).
The set current value Ipms is determined by Ipms (set current value) × Va × Ton / T which is the average power of the Peltier element 4.
In this case, the comparator 10 outputs “L” when Ip> Ipms, and controls the power by changing the Ton time so that the average power becomes Ipms (set current value) × Va × Ton / T. It goes without saying that the input signal to the differential input terminal of the comparator 10 can be switched between the plus terminal and the minus terminal.

FIG. 4 is a block diagram showing a configuration of an average power control system using the Peltier device driving apparatus according to the third embodiment. 4 that are the same as those in FIGS. 1 and 3 are given the same reference numerals, and descriptions thereof are omitted.
The Peltier device control unit of the average power control system shown in FIG. 4 sets the average power data in the setting register 8, so that the differential input terminal of the comparator 10 is used as a reference voltage via the D / A converter 11. I try to input. Therefore, in this case, the set average power is controlled by changing the reference voltage.
FIG. 5 is a block diagram showing a configuration of an average power control system using a Peltier device driving apparatus according to the fourth embodiment. In FIG. 5, the same parts as those in FIG.
The Peltier element control unit of the average power control system shown in FIG. 5 is configured to vary the supply voltage level of the Peltier element 4. In this case, a step-down circuit using an FET 9 and a coil 12 is provided as a drive voltage generation unit of the Peltier element 4.
In this case, the PWM signal is input to the FET 9 by the CPU 2 so that a voltage proportional to the duty is output. Thereby, the power consumption fluctuation of the Peltier device is suppressed depending on the use environment.

FIG. 6 is a diagram showing the supply timing of the drive voltage to the Peltier device when the Peltier device driving apparatus according to the fourth embodiment is turned on.
6A shows a driving trigger signal for driving the Peltier element, FIG. 6B shows a driving voltage for driving the Peltier element 4, and FIG. 6C shows a current of the Peltier element.
The current value of the Peltier element 4 shown in (c) varies depending on the applied voltage level, the temperature difference between the heat generating surface and the heat absorbing surface of the Peltier element, and the like. Current control is performed by varying the power supply voltage level so that the current falls within a certain value. In this case as well, control is performed so that the current of the Peltier element 4 is always within the threshold when the trigger signal shown in (a) is on, regardless of when the power is turned on.
FIG. 7 is a block diagram showing a configuration of an average power control system using the Peltier device driving apparatus according to the fifth embodiment. The same parts as those in FIG.
The Peltier element control unit of the average power control system shown in FIG. 7 uses the comparator 10 instead of the A / D converter 7 used in the Peltier element control unit shown in FIG. 5 to control the average power of the Peltier element 4. Like to do.
In this case, the detection voltage value of the current detection resistor 6 is input to the minus terminal of the differential input terminal of the comparator 10. On the other hand, the fixed voltage value Vref is input in advance to the differential input plus terminal of the comparator 10.
The fixed voltage value Vref can be determined by Vref = R (resistance value) × Ipms (set current value).
The set current value Ipms is determined by Ipms (set current value) × Va × Ton / T which is the average power of the Peltier element 4.
In this case, the comparator 10 outputs “L” when Ip> Ipms, and controls the power by changing the Ton time so that the average power becomes Ipms (set current value) × Va × Ton / T. It goes without saying that the input signal to the differential input terminal of the comparator 10 can be switched between the plus terminal and the minus terminal.

FIG. 8 is a block diagram showing the configuration of an average power control system using the Peltier device driving apparatus according to the sixth embodiment. In FIG. 8, the same parts as those in FIGS.
The Peltier device control unit of the average power control system shown in FIG. 8 sets the average power data in the setting register 8 and inputs it as a reference voltage to the differential input terminal of the comparator 10 via the D / A converter 11. Like to do. Therefore, in this case, the set average power is controlled by changing the reference voltage.
FIG. 9 is a block diagram showing a configuration of a humidity control system using the Peltier device driving apparatus according to the seventh embodiment. In FIG. 9, the same parts as those in FIG.
The humidity control system shown in FIG. 9 is configured such that the CPU 21 performs on / off control of the Peltier element driving device based on information from the humidity sensor 13 input via the A / D converter 7.
FIG. 10 is a block diagram showing a configuration of a temperature / humidity control system using the Peltier device driving apparatus according to the eighth embodiment. 10, parts that are the same as those in FIG. 9 are given the same reference numerals, and unnecessary descriptions are omitted.
In the temperature / humidity control system for controlling temperature or humidity shown in FIG. 10, the air volume is variable by the drive voltage for driving the Peltier element 4 in the CPU 21 based on the information of the temperature / humidity sensor 13 a input via the A / D converter 7. The device (fan) 23 is operated. The fan 23 and the motor drive circuit 24 are configured to send air cooled by the Peltier element 4 and dry air. In this case, the temperature or humidity is efficiently controlled by controlling the air volume of the fan 23 by the power supply voltage of the Peltier element 4. For example, when the power supply voltage is low (when the duty is small), a command to reduce the motor rotation speed is commanded to the motor control IC of the fan motor to reduce the air volume of the fan motor.
Here, the D / A converter 25 is used to control the rotational speed of the fan motor of the fan 23 and the speed can be set with an analog value. However, the rotational speed control method of the fan motor is not particularly limited.

FIG. 11 is a flowchart for explaining average power control in the Peltier element driving device of the PWM driving system according to the present invention.
The Peltier device driving apparatus of this embodiment is configured to control the drive voltage of the Peltier device with a set average power of 48 W by varying the PWM duty of a 12 V power source at a frequency of 2 kHz.
When the Peltier element 4 is on (when starting up and during on-off control), the PWM duty is set to 20% and a drive voltage is supplied to the Peltier element 4 according to a Peltier element on command (S1). Next, the 1s counter which is one of the timer counters 5 is counted up (S2). Next, an average power (Ip × 12V × 0.2) is calculated every 1 s and compared with 48 W (S3). When the average power is 48 W or less and the timer counter 5 counts for 15 s (S4), the PWM duty is increased by 20% and the drive voltage is supplied to the Peltier element 4 (S5). That is, the average power calculation is performed every 1 s and is 48 W or less. When the timer counter 5 counts 15 s, the PWM duty is increased by 20% and the drive voltage is supplied to the Peltier element 4. The duty is increased by 20% every 15 seconds, and when the average power is 48 W or less and the power supply voltage of the Peltier element 4 reaches 12 V, the start-up is completed.
If the calculation result exceeds 48 W in step (S3), the duty is reduced by 20% and the Peltier element is driven (S8). Then, after 15 seconds (S4), it is again increased by 20% (S5), and it is compared whether the average power is 48 W or less (S7), and the above is repeated while changing the duty so that the average power is within 48 W (S9). When the average power is 48 W or less, the process ends.

FIG. 12 is a flowchart for explaining current control in the variable voltage type Peltier device driving apparatus according to the present invention.
In this case, the Peltier device driving device changes the supply voltage by changing the PWM duty and controls the current Ipms = 4 A (at the time of start-up and on-off control).
When the Peltier element 4 is turned on, a 2.4V output (PWM duty 10%) is generated by an on command of the Peltier element 4, and a drive voltage is supplied to the Peltier element (S11).
Next, the 1s counter which is one of the timer counters 5 is counted up (S12). Ip is A / D converted every 1 s, and the current value is compared with 4 A (S13). When Ip <4A and 15 s are counted by the timer counter 5 (S15), the PWM duty is increased by 10% and the drive voltage of the Peltier element 4 is set to 4.8V.
If the current Ip exceeds 4 A, the Peltier element is driven by reducing 2.4 V (duty 10%) (S 14). The current is sampled every 1 s and the current value is detected. When the timer counter 5 counts for 15 seconds, the PWM duty is further increased by 10% and the drive voltage of the Peltier element 4 is set to 7.2V. When Ip <4A and every 15 s, the duty is increased by 10%, and when the Peltier element power supply voltage reaches 12 V (S16), the start-up is completed.
If the duty is 50% (S17) and the current Ip exceeds 4A (S18), the Peltier element is driven by reducing 2.4V (duty is 10%) (S19). Then, step (S12) and subsequent steps are repeated, and after 15 s, 2.4 V (duty is increased by 10%) is again increased to compare whether the current Ip is 4 A or less (S16), so that Ip is within 4 A (S17). Start up to a duty of 12V while changing the duty (S16).

FIG. 13 is a schematic view showing a control system for controlling the temperature of the laser diode in the writing unit for exposing the photosensitive member in the copying machine.
In FIG. 13, a drive voltage is supplied to the Peltier element device 16 from the power supply control board 15, and the power supply control board 15 is connected to the Peltier element device 16 and a temperature sensor. The Peltier element device 16 includes heat radiating fins 18 and fan motors 19 and 20 at both ends of the Peltier element 17. A voltage is applied to the Peltier element 17, and the heat generating surface of the Peltier element 17 is exhausted to the outside by the fan motor 19. Then, low-temperature air is poured into the writing unit 22 through the duct 21 by the fan motor 20 on the heat absorption surface of the Peltier element 17. The high-temperature air in the unit is exhausted through the duct 29 by the fan motor 24.
The temperature in the unit is detected by the temperature sensor 25 and the temperature of the laser diode in the writing unit 22 can be controlled by controlling the Peltier device 16 by the CPU in the temperature control board 15.
FIG. 14 is a schematic diagram of a system for controlling the humidity in the photosensitive unit in the copying machine.
The power control board 15 is for supplying power to the Peltier device 16 and is connected to the Peltier device 16 and the humidity sensor 31. The Peltier element device 16 includes heat dissipating fins 18 and fan motors 19 and 20 at both ends of the Peltier element 17. A voltage is applied to the Peltier element 17, and the heat generating surface of the Peltier element 17 is exhausted to the outside by the fan motor 20. Then, the air on the heat absorption surface of the Peltier element 17 is cooled, and the dry air is poured into the photoreceptor unit 26 through the duct 21 by the fan motor 20. The high-humidity air in the photoconductor unit 26 is exhausted through the duct 29 by the fan motor 24. The humidity in the photoconductor unit 26 is monitored by the humidity sensor 31, and the environment of the photoconductor unit 26 can be controlled by controlling the Peltier device 16 by a CPU (not shown) in the control board 15.
FIG. 15 is a schematic diagram of a system for controlling dehumidification of paper in a paper tray in a copying machine. The humidity sensor 31 provided in the paper tray 28 monitors the humidity in the paper tray 28, and the CPU (not shown) in the control board 15 controls the Peltier device 16 to enable environmental control of the paper 27. .
Note that the known operations of the copying machine and the printer are not directly related to the present invention, and thus detailed description thereof is omitted.

The present invention can be implemented by the above configuration and operation control.
The Peltier device driving apparatus according to this embodiment uses an A / D converter to monitor a current value, A / D converts the value detected by the A / D converter, and supplies it to the CPU 2. The average power can be finely controlled.
Further, since the Peltier device driving device of the present embodiment only compares the reference value with a comparator for monitoring the current value, the Peltier device driving device uses a comparator to monitor the current and provides only an upper limit. It can be configured only by a hard circuit, and the system can be easily and inexpensively.
In addition, the Peltier device driving device according to the present embodiment can control the comparison voltage of the comparator more finely by providing two or more reference values to be compared by the comparator 10.
Further, the Peltier element driving device of the present embodiment can operate the average power consumption of the Peltier element driving device by the power consumption consumed by other devices when the driving voltage is a common power supply with other devices. Electric power that can be consumed can be set.
In addition, the Peltier element driving device of the present embodiment can control the current consumed by the Peltier element by monitoring the current of the Peltier element and operating the supply voltage.
Further, when controlling the power or current in the Peltier device driving device of the present embodiment, the CPU 2 executes a control program when receiving a command for operating the driving voltage of the Peltier device. Therefore, the Peltier device driving device of the present embodiment is By storing the drive control program for the Peltier element together with other execution programs in the CPU 2, the Peltier element drive device can be combined with other devices.
Furthermore, according to the present embodiment, the average power consumption or the average current of the system that controls on / off of the Peltier element 4 is controlled based on the information of the humidity sensor 13, so that the Peltier element driving device is a Peltier element in the humidity control system. It is possible to control the power consumption of the element driving device or the average current.

Further, according to the present embodiment, it is known that a writing apparatus using a semiconductor laser of the image forming apparatus causes a position shift of the imaging optical system due to temperature.
Therefore, temperature control is performed using a Peltier element so that the laser diode is used in a constant temperature environment, and the power consumption of the image forming apparatus can be controlled.
In addition, the storage humidity of the photoreceptor of the image forming apparatus affects the life of the photoreceptor. It has also been found that the toner adhesion and the subsequent transfer are affected by the humidity of the photosensitive member during image formation. Therefore, according to the present embodiment, the power consumption of the image forming apparatus can be controlled by using the Peltier element so that the photosensitive drum is used in a constant humidity environment.
In addition, the Peltier element driving device of the present embodiment can be used for humidity control of transfer paper in the paper feed tray of the image forming apparatus, thereby controlling the power consumption of the image forming apparatus.
In addition, the Peltier device driving device of the present embodiment can obtain a stable photosensor output by keeping the sensor temperature constant by using the humidity control of a photosensor such as an LED and a photodiode or a phototransistor.
Further, by using the Peltier device driving device of this embodiment as a toner adhesion amount detection sensor of an image forming apparatus, it is possible to provide a high-quality image and control power consumption. Furthermore, by using the Peltier device driving device of this embodiment as a color misregistration detection sensor of a color image forming apparatus, it is possible to provide a high-quality image and control power consumption.

The block diagram which showed the structure of the average power control system using the Peltier device drive device which concerns on the 1st Embodiment of this invention. The figure which showed the supply timing of the drive voltage to the Peltier device at the time of power activation of the Peltier device drive device concerning a 1st embodiment. The block diagram which showed the structure of the average power control system using the Peltier device drive device which concerns on 2nd Embodiment. The block diagram which showed the structure of the average power control system using the Peltier device drive device which concerns on 3rd Embodiment. The block diagram which showed the structure of the average power control system using the Peltier device drive device which concerns on 4th Embodiment. The figure which showed the supply timing of the drive voltage to the Peltier device at the time of power activation of the Peltier device drive device concerning a 4th embodiment. The block diagram which showed the structure of the average power control system using the Peltier device drive device which concerns on 5th Embodiment. The block diagram which showed the structure of the average power control system using the Peltier device drive device which concerns on 6th Embodiment. The block diagram which showed the structure of the humidity control system using the Peltier device drive device which concerns on 7th Embodiment. The block diagram which showed the structure of the temperature / humidity control system using the Peltier device drive device which concerns on 8th Embodiment. 6 is a flowchart for explaining average power control in the Peltier device driving device of the PWM driving system according to the present invention. The flowchart explaining the current control in the variable voltage system Peltier device driving device according to the present invention. FIG. 2 is a schematic diagram showing a control system for controlling the temperature of a laser diode in a writing unit that exposes a photosensitive member in a copying machine. 1 is a schematic view of a system for controlling humidity in a photoconductor unit in a copying machine. 1 is a schematic diagram of a system for controlling dehumidification of paper in a paper tray in a copying machine.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Peltier device drive device, 2 CPU, 3 Power supply device, 4 Peltier device, 5 Timer counter, 6 Current detection resistor, 7 A / D converter, 8 Setting register, 9 Switching drive device (power supply generation part, FET), 10 Comparator , 11 D / A converter, 12 coil, 13 humidity sensor, 15 control board, 16 Peltier device, 17 Peltier device, 22 writing unit, 23 fan, 24 motor drive circuit (fan motor), 25 temperature sensor, 26 photoconductor Unit, 28 Paper tray, 31 Humidity sensor

Claims (17)

  A DC power supply device for driving the Peltier element; and switching means for switching the drive voltage of the DC power supply device. When the Peltier element is turned on, the supply period for supplying the drive voltage to the Peltier element is gradually lengthened. In the Peltier device driving device that performs pulse width modulation of the drive voltage of the Peltier element so that the supply period for supplying the drive voltage to the Peltier device is gradually shortened when the Peltier device is off, the current flowing through the Peltier device is A Peltier device driving device comprising: a current detection unit for detecting; and a control unit for controlling an on / off cycle of the switching unit based on a detection current detected by the current detection unit.   2. The Peltier device driving device according to claim 1, wherein the control unit includes an A / D converter that performs A / D conversion on a detection current of the current detection unit.   2. The Peltier device driving apparatus according to claim 1, wherein the control unit includes a comparator that compares a detection current of the current detection unit with a predetermined reference value.   An average power consumption setting unit that sets an average power consumption of the Peltier element is provided, and the control unit controls an on / off cycle of the switching unit based on setting data of the average power consumption setting unit. The Peltier device driving device according to any one of claims 1 to 3.   A variable DC power supply that supplies a drive voltage to the Peltier element, and when the Peltier element is turned on, the drive voltage supplied from the variable DC power supply to the Peltier element is gradually increased, and when the Peltier element is turned off, In a Peltier element driving device that controls the driving voltage supplied from the variable DC power supply device to the Peltier element to gradually decrease, a current detection unit that detects a current flowing in the Peltier element, and a detection that is detected by the current detection unit And a control means for controlling an output voltage output from the variable DC power supply device based on an electric current.   6. The Peltier device driving device according to claim 5, wherein the control unit includes an A / D converter that performs A / D conversion on a detection current of the current detection unit.   6. The Peltier device driving apparatus according to claim 5, wherein the control unit includes a comparator that compares a detection current of the current detection unit with a predetermined reference value.   A maximum supply current setting unit configured to set a maximum supply current to be supplied to the Peltier element; and the control unit varies the output voltage of the variable DC power supply so that the current value of the Peltier element is always a set current value. The Peltier element driving device according to claim 5, wherein control is performed so that   Humidity detection means is provided in the vicinity of the part to be measured and detects the humidity in the vicinity of the part to be measured, and the control means controls driving of the Peltier element based on the detection result of the humidity detection means. The Peltier device driving device according to any one of claims 1 to 8, wherein   A temperature detection unit is provided in the vicinity of the component to be measured and detects a temperature in the vicinity of the component to be measured, and the control unit controls driving of the Peltier element based on a detection result of the temperature detection unit. The Peltier device driving device according to claim 1, wherein the Peltier device driving device is a device.   A fan that sends air to the Peltier element; and fan drive voltage supply means that supplies a drive voltage to the fan, wherein the drive voltage of the fan is changed according to the output voltage of the variable DC power supply device. The Peltier device driving device according to claim 9 or 10.   An image forming apparatus using the Peltier device driving device according to claim 1 for temperature control of a laser diode.   12. An image forming apparatus using the Peltier device driving device according to claim 1 for humidity control of a photosensitive drum.   An image forming apparatus using the Peltier device driving device according to claim 1 for humidity control of dehumidification of a sheet.   An image forming apparatus using the Peltier device driving device according to claim 1 for temperature control of an optical sensor.   12. An image forming apparatus, wherein the Peltier device driving device according to claim 1 is used for temperature control of a toner adhesion amount detection sensor.   12. An image forming apparatus using the Peltier device driving device according to claim 1 for temperature control of a color misregistration detection sensor.

Images