EP2282139A2

EP2282139A2 - Heater and hair care device including the same

Info

Publication number: EP2282139A2
Application number: EP10166110A
Authority: EP
Inventors: Takuji Sohmura; Itaru Saida
Original assignee: Panasonic Electric Works Co Ltd
Current assignee: Panasonic Corp
Priority date: 2009-06-29
Filing date: 2010-06-16
Publication date: 2011-02-09
Also published as: JP2011005150A; JP5295012B2; RU2426034C1; CN101936599A; CN101936599B

Abstract

A heater includes: a power supply section (1) supplying predetermined power; a heating section (4) which is supplied with power from the power supply section (1) to be heated; a first power supply path for supplying the power from the power supply section (1) to the heating section (4); a power control switch section (6) which is inserted in the first power supply path and selectively supplies power to the heating section (4); a controller (3) which is supplied with power from the power supply section (1) and controls the selective power supply by the power control switch section (6); a second power supply path for supplying power from the power supply section (1) to the controller (3); and a body switch section (2) which is inserted in the second power supply path and selectively supplies power to the controller (3).

Description

Technical Field

The present invention relates to a heater in which power supply to a controller controlling a heating section is controlled, and relates to a hair care device including the heater.

Background Art

One of such conventional techniques is a technique for a futon hot blower described in PTL 1, in which an energization control circuit turns a heater on and off based on signals from a microcomputer to control the temperature of the heater.

Citation List

Patent Literature

[PTL 1] Japanese Patent Laid-open Publication No- 7-136393

Summary of Invention

In the aforementioned conventional art, a direct-current power circuit is configured to give a driving power supply for driving a microcomputer and an energization control circuit when the blower is supplied with commercial power source. In such a structure, when the blower is supplied with commercial power source, the microcomputer and energization control circuit are given the driving power supply and are supplied with current regardless of whether or not the heater is on. Accordingly, the electric power is consumed even when the drawer does not blow hot air, thus causing high standby power consumption and increasing the operating cost.
The present invention was made in the light of the aforementioned problem. An object of the present invention is to provide a heater with reduced operating cost and a hair care device including the same.
A heater according to a first aspect of the present invention includes: a power supply section supplying predetermined power; a heating section which is supplied with power from the power supply section to be heated; a first power supply path for supplying the power from the power supply section to the heating section; a power control switch section which is inserted in the first power supply path and selectively supplies power to the heating section; a controller which is supplied with power from the power supply section and controls the selective power supply by the power control switch section; a second power supply path for supplying power from the power supply section to the controller; and a body switch section which is inserted in the second power supply path and selectively supplies power to the controlled.
Such a configuration reduces standby power consumption and therefore reduces operating cost.
The controller changes an energization period in which the heating section is energized, thereby changing an energization ratio of the heating section.
Such a configuration enables the temperature of the heating section to smoothly change and implements stable temperature control. This reduces unnecessary power consumption, thus achieving low power consumption. The operating cost can be therefore reduced.
The heater may further include a temperature detecting section for detecting temperature of the heating section. The energization ratio of the heating section is changed based on a difference between a target setting temperature of the heating section and the temperature of the heating section detected by the temperature detecting section.
With such a configuration, the temperature of the heating section can be controlled so as to quickly rise and not to vary a lot with respect to the setting temperature, implementing stable temperature control and achieving low power consumption.. The operating cost can be therefore reduced.
The controller calculates a change in temperature of the heating section per unit time and decreases the energization ratio when an increment in temperature increases while increasing the energization ratio when a decrement in temperature decreases.
With such a configuration, the temperature of the heating section can be controlled so as not to vary a lot with respect to the setting temperature, implementing stable temperature control and achieving low power consumption. The operating cost can be therefore reduced.
In stead of the above configuration, the controller may calculate a change in temperature of the heating section per unit time, calculate an amount of feedback negative-proportional to the calculated change in temperature, weight the change in temperature and the amount of feedback according to heat capacity of the heating section, and change the energization ratio based on the weighted change in temperature and amount of feedback.
Such a configuration allows stable temperature control to be performed for devices with different heat capacities, reducing the power consumption and reducing the operating cost.
A hair care device according to a second aspect of the present invention includes the heater according to the first aspect of the present invention.
Such a configuration can provide a hair care device in which the operating cost is reduced by reducing the stand-by power consumption.

Brief Description of Drawings

FIG. 1 is a block diagram illustrating a configuration of a heater of Embodiment 1 of the present invention.
FIG. 2 is a diagram illustrating a specific configuration example of the heater illustrated in FIG. 1.
FIG. 3 is a diagram illustrating temperature control in a heating section with the configuration illustrated in FIG. 2.
FIG. 4 is a time chart illustrating energization patterns in a heater of Embodiment 2 of the present invention.
FIG. 5 is a chart illustrating temperature control in a heater of Embodiment 3 of the present invention.
FIG. 6 is a chart illustrating temperature control in a heater of Embodiment 4 of the present invention..
FIG. 7 is a cross-sectional view illustrating a structure of a hair dryer as a hair care device according to Embodiment 7 of the present invention.
FIG. 8A is a side view illustrating a structure of a hair iron as the hair care device according to Embodiment 7 of the present invention.
FIG. 8B is a cross-sectional view illustrating the structure of the hair iron as the hair care device according to Embodiment 7 of the present invention.
FIG. 9 is a cross-sectional view illustrating a structure of a hair brush as the hair care device according to Embodiment 7 of the present invention.

Description of Embodiment

Hereinafter, embodiments for carrying out the invention are described using the drawings.

(Embodiment 1)

FIG. 1 is a block diagram illustrating a configuration of a heater according to Embodiment 1 of the present invention. The heater of Embodiment 1 includes a power supply section 1, a body switch section 2, a controller 3, a heating section 4, a temperature detecting section 5, and a power control switch section 6.
The power supply section 1 includes a direct-current (DC) power source with a predetermined power output or receives electric power supply from an alternate-current (AC) power source to supply electric power to the entire heater. The body switch section 2 is connected to between the power supply section 1 and controller 3 and turns a switch on/off to control switching of power supply from the power supply section 1 to the controller 3. The controller 3 receives power supply from the power supply section 1 through the body switch section 2. The controller 3 controls switching (on/off) of the power control switch section 6 based on temperature of the heating section 4 to control driving current supplied to the heating section 4. The heating section 4 is supplied with the driving current from the power supply section 1 through the power control switch section 6 under the control of the controller 3 and generates heat to be heated so as to reach a previously set temperature. The temperature detecting section 5 detects the temperature of the heating section 4 and gives the detected temperature to the controller 3. The power control switch section 6 is directly connected to the power supply section 1 and controls the switching of power supply to the heating section 4 under the control of the controller 3.
FIG. 2 is a diagram illustrating a specific configuration example of the heater illustrated in FIG. 1. In FIG. 2, the power supply section 1 is composed of a DC power supply VCC supplying a predetermined electric power. The body switch section 2 is composed of a slide switch SW1, for example. In the case where the power supply section 1 is configured to receive AC power, the power supply section 1 has a function of rectifying and smoothing the AC power into DC power. The controller 3 includes a microcomputer M1 having a CPU, a storage unit, input/output units, and the like, which are resources necessary for a computer controlling various operating processes based on programs. The controller 3 includes a resistor R1 connected to the temperature detecting section 5 in series between the DC power supply VCC and temperature detecting section 5.
The heating section 4 is composed of a resistor R. The temperature detecting section 5 is composed of a thermistor R2. The voltage of the DC power supply VCC is divided by the resistor R1 and the thermistor R2: The divided voltage obtained at a connection point where the resistor R1 and thermistor R2 are connected in series is given to the microcomputer M1 as a temperature detection signal. The power control switch section 6 is composed of a thyristor Q connected to between the heating section 4 and DC power supply VCC. Switching of the thyristor Q is controlled with gate current thereof which is controlled by the microcomputer M1.
In such a configuration, when the slide switch SW1 of the body switch section 2 is switched from OFF state to ON state to conduct electricity, the DC power supply VCC supplies the microcomputer M1 with rated current previously set for the microcomputer M1 to activate the microcomputer M1. Thereafter, the divided voltage obtained by dividing the voltage of the DC power supply VCC with the resistor R1 and thermistor R2 is given to the microcomputer M1. The microcomputer M1 compares the divided voltage and a voltage value obtained by converting the setting temperature of the heating section 4 (heating target temperature). The setting temperature is previously determined as a predetermined value and is stored in the storage unit of the microcomputer M1 or the like.
As a result of the comparison, if the temperature detected by the thermistor R2 is not more than the setting temperature, as illustrated in FIG. 3, the microcomputer M1 gives a high-level switching control signal to the thyristor Q. This causes the thyristor Q to be turned from a not-conducting state to a conducting state, thus supplying the driving current from the DC power supply VCC to the resistor R of the heating unit 4. The heating section 4 thus generates heat, and the temperature of the heating section 4 gradually increases from the room temperature as illustrated in FIG. 3.
In such a state, when the temperature of the heating section 4 detected by the thermistor R2 exceeds the setting temperature previously determined, the switching control signal given from the microcomputer M1 to the thyristor Q changes from high (H) to low (L). The thyristor Q is turned from the conducting state to a not-conducting state to shut off the driving current supplied to the heating section 4. The heat generation of the heating section 4 is stopped, and the temperature of the heating section 4 falls. By switching the thyristor Q as described above, the driving current from the DC power supply VCC to the heating section 4 is supplied and_shut off. Accordingly, the heating section 4 can be maintained at the setting temperature.
In Embodiment 1, the power control switch section 6 is off when the body switch section 2 is off and the controller 3 is not supplied with electric power. This prevents current from the power supply section 1 from being supplied to the controller 3 and power control switch 6 when the power body switch section 2 is off. It is therefore possible to reduce standby power consumption and therefore reduce operating cost.
Moreover, the controller 3 is not supplied with electric power when the body switch section 2 is off and the heater does not work. This can prevent the controller 3 from being affected by noise or the like and causing errors. Furthermore, it is avoided that the driving current supplied to the heating section 4 is conducted to the body switch section 2. Accordingly, the operating current of the microcomputer M1, which is smaller than the driving current supplied to the heating section 4, is applied to the body switch section 2. The body switch section 2 can be composed of a switch with a smaller rated current in Embodiment 1 than that in the case where the driving current for the heating section 4 is conducted to the body switch section 2. Accordingly, the heater can be miniaturized.

(Embodiment 2)

FIG. 4 is a time chart in temperature control employed in a heater of Embodiment 2 of the present invention. In Embodiment 1, the switching control signal, which is given from the microcomputer M1 to the gate terminal of the thyristor Q, changes from H to L, or from L to H according to the temperature of the heating section 4 as illustrated in FIG. 3. On the other hand, Embodiment 2 is characterized in that the switching of the thyristor Q is controlled according to energization (on/off) patterns previously set.
The switching control signal supplied from the microcomputer M1 to the gate terminal of the thyristor Q includes six patterns of energization periods illustrated in FIG. 4, patterns 0 to 5. Specifically, these patterns have energization periods and ratios for unit period as follows:

Pattern 0- energization period: 0
Pattern 1- energization period: 5, energization ratio: 1/5
Pattern 2- energization period: 4, energization ratio: 1/4
Pattern 3- energization period: 3, energization ratio: 1/3
Pattern 4- energization period: 2, energization ratio: 1/2
Pattern 5- energization period: 1, energization ratio: 1

The switching control signals having the different energization patterns are properly selected and combined to be supplied to the thyristor Q. In other words, the energization ratio is changed by intermittently controlling energization of the heating section 4. The temperature of the heating section 4 can be controlled more accurately than the simple on/off control which supplies the driving current to the heating section 4 if the temperature of the heating section 4 is not more than the setting temperature and shuts off the driving current to the heating section 4 if the temperature of the heating section 4 exceeds the setting temperature. The temperature control can be therefore improved. The temperature of the heating section 4 smoothly changes and does not vary a lot, thus implementing stable temperature control. It is therefore possible to reduce unnecessary power consumption and achieve low power consumption, thus reducing the operating cost.

(Embodiment 3)

FIG. 5 is a time chart for temperature control employed in a heater of Embodiment 3 of the present invention. Compared to Embodiment 2 above, Embodiment 3 is characterized by selecting a pattern from the energization patterns illustrated in FIG. 4 based on the difference between the setting temperature of the heating section 4 and the current temperature of the heating section 4 detected by a thermistor R2 constituting the temperature detecting section 5.
First, if the heating section 4 is at room temperature after the body switch section 2 is turned from the OFF state to the ON state, the current temperature of the heating section 4 is much different from the setting temperature thereof. Accordingly, if the temperature of the heating section 4 is not more than (the setting temperature - 8°C), for example, the pattern 5 illustrated in FIG. 4 is selected to set the energization ratio to 1.
If the temperature of the heating section 4 then increases and reaches (the setting temperature - 8°C), the pattern 4 illustrated in FIG. 4 is selected to reduce the energization ratio to 1/2. Subsequently, if the temperature of the heating section 4 further increases and reaches (the setting temperature 6°C), the pattern 3 illustrated in FIG. 4 is selected to set the energization ratio to 1/3. Similarly, if the temperature of the heating section 4 reaches (the setting temperature - 4°C), the pattern 2 illustrated in FIG. 4 is selected to set the energization ratio to 1/4. If the temperature of the heating section 4 reaches (the setting temperature - 2°C), the pattern 1 illustrated in FIG. 4 is selected to set the energization ratio to 1/5.
If the temperature of the heating section 4 then reaches the setting temperature, the pattern 0 is selected so as not to energize the heating section 4, and such a state is maintained until the temperature of the heating section 4 falls to the setting temperature or below. If the temperature of the heating section 4 falls to the setting temperature or below, the pattern 1 illustrated in FIG. 4 is selected to again start energization with the energization ratio of 1/5. As the heating section 4 decreases in temperature, the pattern 2 illustrated in FIG. 4 is selected at a temperature of (the setting temperature - 2°C) to set the energization ratio to 1/4, and the pattern 3 illustrated in FIG. 4 is selected at a temperature of (the setting temperature - 4°C) to set the energization ratio to 1/3. By changing the energization ratio according to the temperature difference between the temperature of the heating section 4 and the setting temperature thereof in such a manner, the temperature of the heating section 4 is controlled so as to converge to the setting temperature. Depending on the heat capacity of the heating section 4, the temperature of the heating section 4 sometimes cannot be maintained without energization even after the temperature of the heating section 4 exceeds the setting temperature. In such a case, energization of the heating section 4 is continued even after the temperature of the heating section 4 exceeds the setting temperature.
In Embodiment 3, when the temperature of the heating section 4 is considerably lower than the setting temperature, the temperature of the heating section 4 is quickly raised by setting the energization ratio to 1. Moreover, as the temperature of the heating section 4 increases to the setting temperature, the energization ratio is decreased in a stepwise manner. This prevents a rapid rise in temperature of the heating section 4 and avoids overshoot. Furthermore, when the temperature of the heating section 4 falls from the setting temperature, the energization ratio is increased as the difference between the temperature of the heating section 4 and the setting temperature thereof increases. The temperature of the heating section 4 can be thus raised close to the target temperature.
Such temperature control executed by the microcomputer M1 can provide a quick rise of the temperature of the heating section 4 and prevent the temperature of the heating section 4 from varying a lot with respect to the setting temperature. This leads to stable temperature control and reduces unnecessary power consumption, thus reducing the power consumption and therefore reducing the operating cost.

(Embodiment 4)

FIG. 6 is a time chart in temperature control employed in a heater according to Embodiment 4 of the present invention. Embodiment 4 is characterized by adding an amount of feedback to selection of the energization pattern employed in Embodiment 3 above.
The microcomputer M1 stores the temperature of the heating section 4 measured a unit time before as a previous temperature and calculates the difference between the stored previous temperature and current temperature of the heating section 4. For example, as illustrated in FIG. 6, when the difference between the stored previous temperature and current temperature of the heating section 4 is 0, the change in temperature is represented as 0. If the current temperature is 1°C higher than the previous temperature, the change in temperature is represented as +1. If the current temperature is 2°C higher than the previous temperature, the change in temperature is represented as +2. If the current temperature is 1°C lower than the previous temperature, the change in temperature is represented as -1 If the current temperature is 2°C lower than the previous temperature, the change in temperature is represented as -2. The unit time is previously set to an arbitrary time.
The microcomputer M1 calculates the amount of feed back which is negative-proportional to the change in temperature. For example, as illustrated in FIG. 6, if the change in temperature is 0, the amount of feedback is set to 0. Similarly, the amount of feedback is set to -1, -2, +1, and +2 for changes in temperature of+1, +2, -1, and -2, respectively.
The energization patterns 0 to 5, which are the same as those of Embodiment 3, are quantified to numerical values. Specifically, the patterns 0 to 5 are represented as 0, +1, +2, +3, +4, and +5, respectively.
The microcomputer M1 adds up the thus-calculated amount of feedback and the numerical value obtained by quantifying the energization pattern and selects another energization pattern corresponding to the numerical value resulting from the addition. If the result of the addition is a negative value, the pattern 0 is selected.
First, an energization pattern is selected for the change in temperature of the heating section 4 based on the difference between the current temperature of the heating section 4 and the setting temperature thereof in a similar manner to Embodiment 3. Next, the amount of feedback is calculated for the selected energization pattern, and then the calculated amount of feedback is added to the numerical value for the selected energization pattern.
For example, as illustrated in FIG. 6, if the change in temperature is 0 after the energization of the heating section 4 is started, the amount of feedback is set to 0. Then the numerical value +5 of the selected pattern is added to the amount of feedback of 0, and the pattern 5 corresponding to the sum of +5 is selected. If the temperature of the heating section 4 rises and the change in temperature becomes +1., the amount of feedback is set to -1. The amount of feedback of -1 is added to the numerical value of +5 for the pattern 5 selected, and the pattern 4 corresponding to the sum of +4 is then selected. In a similar manner, as illustrated in FIG. 6, the energization pattern is determined by adding the amount of feedback to the energization pattern selected by the method employed in Embodiment 3.
As described above, by detecting the change in temperature of the heating section 4 per unit time and employing the energization ratio which decreases as the increment in temperature of the heating section 4 increases, the temperature of the heating section 4 is prevented from excessively rising much above the target temperature- In some cases, the detected increment in temperature of the heating section 4 per unit time is larger than a real increment in temperature of the heating section 4 per unit time because the temperature detected by the temperature detecting section 5 is much different from real temperature of the heating section 4. Even in such a case, the temperature of the heating section 4 is prevented from excessively rising much above the target temperature.
In a similar manner, by detecting the change in temperature of the heating section 4 per unit time and employing the energization ratio which decreases as the decrement in temperature of the heating section 4 increases, the temperature of the heating section 4 is prevented from excessively falling much below the target temperature. In some cases, the detected decrement in temperature of the heating section 4 per unit time is larger than a real decrement in temperature of the heating section 4 per unit time because the temperature detected by the temperature detecting section 5 is much different from real temperature of the heating section 4. Even in such a case, the temperature of the heating section 4 is prevented from excessively falling much below the target temperature.
The aforementioned temperature control executed by the microcomputer 1. allows the temperature of the heating section 4 to quickly rise and prevents the temperature of the heating section 4 from varying a lot with respect to the setting temperature. This leads to stable temperature control and reduces unnecessary power consumption, thus reducing the power consumption and therefore reducing the operating cost.

(Embodiment 5)

Next, Embodiment 5 of the present invention is described. Compared to Embodiment 4 previously described, Embodiment 5 is characterized by weighting the change in temperature and the amount of feedback according to heat capacity of the heating section 4 for adjustment.
The microcomputer M1 adds up a product of a coefficient A and the difference between the current temperature and setting temperature of the heating section 4 and a product of a coefficient B and the amount of feedback calculated corresponding to the difference between the current temperature and setting temperature of the heating section 4. The microcomputer M1 then selects an energization pattern corresponding to the result of the addition. Herein, the magnitude relation between the coefficients A and B, which are weighting coefficients, is set according to the heat capacity of the heating section 4. Specifically, the coefficients A and B are set as: the coefficient A < the coefficient B for large heat capacity of the heating section 4; and the coefficient A > the coefficient B for small heat capacity of the heating section 4.
In such a manner, it is selected whether or not to reflect the amount of feedback on the selection of the energization pattern more than the change in temperature according to the heat capacity of the heating section 4. By setting the coefficients A and B to proper values, stable temperature control similar to Embodiment 4 can be performed for the heater with a different heat capacity This reduces unnecessary power consumption, thus achieving low power consumption. The operating cost can be therefore reduced.

(Embodiment 6)

FIGS. 7 to 9 are views illustrating structures of hair care devices each including the heater of the present invention. FIG. 7 is a cross-sectional view of a hair dryer; FIG. 8A is a side view of a hair iron; FIG. 8B is a cross-sectional view of the hair iron illustrated in FIG. 8A; and FIG. 9 is a cross-sectional view of a hair brush.
In FTC-. 7, the hair dryer as the hair care device includes a cavity within a case 12 forming an outer wall thereof. In this cavity, an electrical part 13 constituting the heater of the present invention is arranged and accommodated. The electric part 13 is supplied with commercial power through a power cord 14. The power supply is turned on/off through the body switch section 2, which is provided for a grip 15 that a user grips with his/her hand. The heating section 4 is composed of, for example, a belt-shaped or a corrugated plate-shaped electric resistor which is wound along the internal surface of an inner cylinder 17 and warms air blowing out from an outlet opening 16.
In FIGS. 8A and 8B, the hair iron as the hair care device includes arm sections 19a and 19b, which are coupled to each other with a rotational coupling portion 18 and are pivotally opened substantially in a V-shape. Hair is sandwiched in a holding section 20 provided between top halves of the arm portions 19a and 19b and is heated by the heater section 4 for hair styling. There is a cavity formed within a case 21 forming an outer wall of the hair iron. In the cavity, an electrical part 20 constituting the heater of the present invention is positioned and accommodated, The electric part 22 is supplied with commercial power through a power cord 23. The power supply to the hair iron is turned on/off with the body switch section 2, which is provided for the arm section 19b that a user grips with his/her hand.
In FIG. 9, the hair brush as the hair care device has a stick form. A user grips a grip section 24 and puts a brush section 26, which is provided for a top half 25, on hair for hair styling. There is a cavity formed within a case 27 forming an outer wall of the hair brush. In the cavity, an electrical part 28 constituting the heater of the present invention is arranged and accommodated. The electric part 28 is supplied with commercial power through a power cord 29. The power supply to the hair brush iron is turned on/off with the body switch section 2, which is provided for the grip section 24. The brush section 26 includes air blowing holes 31 at individual feet of a plurality of bristles 30. The heating section 4, which warms air blown out from the air blowing holes 31 by a fan 32, is arranged within the cavity formed within the case 27.
As described above, provision of the heater of the present invention described in Embodiments 1 to 5 for the aforementioned hair care devices allows the temperature control to be stably performed and reduces unnecessary power consumption for low power consumption, reducing the operating cost.

Claims

A heater, comprising:
a power supply section (1) supplying predetermined power;

a heating section (4) which is supplied with power from the power supply section (1) to be heated;

a first power supply path for supplying the power from the power supply section (1) to the heating section (4);

a power control switch section (6) which is inserted in the first power supply path and selectively supplies power to the heating section (4);

a controller (3) which is supplied with power from the power supply section (1) and controls the selective power supply by the power control switch section (6);

a second power supply path for supplying power from the power supply section (1) to the controller (3); and

a body switch section (2) which is inserted in the second power supply path and selectively supplies power to the controller (3).
The heater of claim 1, wherein the controller (3) changes an energization period with which the heating section (4) is energized, thereby changing an energization ratio of the heating section (4).
The heater of claim 2, further comprising:
a temperature detecting section (5) for detecting temperature of the heating section (4), wherein

the energization ratio of the heating section (4) is changed based on a difference between a target setting temperature of the heating section (4) and the temperature of the heating section (4) detected by the temperature detecting section (5).
The heater of claim 3, wherein the controller (3) calculates an increment or a decrement in temperature of the heating section (4) per unit time, and decreases the energization ratio when the increment in temperature of the heating section (4) increases while increasing the energization ratio when the decrement in temperature of the heating section (4) decreases.
The heater of claim 3, wherein the controller (3) calculates a change in temperature of the heating section (4) per unit time, calculates an amount of feedback negative-proportional to the calculated change in temperature, weights the change in temperature and the amount of feedback according to heat capacity of the heating section (4), and changes the energization ratio based on the weighted change in temperature and amount of feedback.
A hair care device, comprising the heater of claim 1.