JPH0686873A - Electric razor - Google Patents

Abstract

PURPOSE:To enable an optimum shaving by peroons from a heavy beard to a light beard, by installing a revolution speed control means which is equipped with the first function for varying the number of revolution of a motor on the basis of the output of an electric current detecting means and the second function for varying the motor revolution speed variation range on the basis of the output of a revolution speed detecting means. CONSTITUTION:An electric razor is equipped witt a revolution speed detecting circuit 2 for detecting the number of revolution of a motor 1, revolution control means, loaded electric current detecting means 4 for the motor 1, and a calculation circuit 5 for calculating the output signal. The calculation circuit 5 determines the number of revolution, taking account of the difference I between the electric current value I detected by the electric current detecting means 4 and the measurement value in the preceding time, and outputs the signal to the revolution control means 3. After the lapse of a certain time after the start of the electrical razor, the range of the variation of the number of revolution is gradually lowered. The calculation circuit 5 receives the data of the number of revolution of the motor 5, and carries out calculation, and judges the beard-thickness, and varies the range of the variation of the number of revolution according to the judgement. Accordingly, the revolution speed setting adjusting range is changed, using the beard-thickness and time as a function.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric shaver for controlling the number of rotations of a motor so that it is most suitable for shaving. In particular, the present invention relates to an electric razor capable of shaving in an optimum state for a person with a thick beard and a person with a thin beard.

[0002]

2. Description of the Related Art A conventional electric shaver has a characteristic that the number of revolutions of a motor increases and the number of revolutions decreases when no load is applied because no means for controlling the number of revolutions of a motor is provided. Such an electric shaver causes the motor to rotate at a high speed when there is no load, and thus consumes unnecessary power. By reducing the number of revolutions when there is no load, it is possible to prevent useless power consumption. To achieve this, an electric shaver that controls the number of revolutions of the motor has been proposed (Japanese Patent Laid-Open No. 62-79084). Issue). The electric shaver described in this publication has a motor rotation speed detection means, and the rotation speed detection means controls the motor rotation control means to control the motor rotation speed to a constant value.

However, this electric razor can prevent wasteful power consumption when there is no load, but in order to control the rotation speed of the motor to a constant value, the optimum rotation speed is adjusted according to the user's whisker depth. Can not be adjusted to. Therefore,
In the case of a person with a thin beard, there are problems that the number of rotations is too high and the attraction of the beard is poor, and that after a shave, the person tends to get caught. On the other hand, in the case of a person with a strong beard, on the contrary, if the number of rotations is too low and the user feels insufficient power, or if the shaving progresses, similarly, it may be difficult to attract the person or a tingling may occur.

The present inventor has already proposed an electric shaver in which the number of revolutions of the motor is changed depending on the shaving state in order to solve this drawback (Japanese Patent Application No. 3-4528).
issue). This electric shaver detects the load current of the motor and controls the number of revolutions. Specifically, as shown in FIG. 1, generally, when the amount of cutting of the beard by the blade decreases as the shaving progresses. Focusing on the fact that the load on the motor becomes lighter and the load current decreases, the rotation speed of the motor is lowered when the load current on the motor decreases.
Therefore, the rotation speed of the motor decreases as the shaving progresses.

According to this electric razor, when the number of rotations of the motor decreases as the shaving progresses, the beard is attracted better, and the shaving can be done neatly, and the scratching can be reduced. For this reason, there is a feature that the rotation speed of the motor is first increased to “roughly shave” with good sharpness, and the rotation speed is gradually reduced to the “finished sledge” state.

By the way, since the number of revolutions of this electric razor decreases as the shaving progresses, it is possible to improve the attractiveness of the shaving and whiskers. However, as shown in FIG. 2, the number of revolutions of the motor is 6000. Since the number of rotations of the motor is changed within a fixed range of ~ 7500 rpm, when a person with a thick beard uses it, it lacks sharpness, and when a person with a thin beard uses it, it causes a problem of tingling. Is not resolved. That is, when the region in which the number of revolutions changes is matched to a person with a thick beard, a thin person has a high tendency to get caught, and when matched with a person with a thin beard, the sharpness of a person with a dark hair is further deteriorated.

[0007]

SUMMARY OF THE INVENTION The present invention has been proposed for the purpose of solving this drawback, and it is achieved by varying the region where the rotation speed of the motor changes in accordance with a person with a strong beard or a person with a thin beard. , To provide an electric razor that can be shaved in the best condition for both beard and thin beards.

[0008]

According to the present invention, there is provided a motor for driving a blade, a current detection means for detecting a load current of the motor, a rotation speed detection means for detecting a rotation speed of the motor, and the current detection. A rotation having a first function of changing the rotation speed of the motor based on the output of the means, and a second function of changing the rotation speed change region of the motor based on the output of the rotation speed detection means. And a number control means.

Further, the electric shaver is characterized in that the electric shaver is provided with an arithmetic means for storing the data of the rotational speed detected by the rotational speed detecting means and rearranging the data in descending order.

[0010]

According to the present invention, the rotation speed control means has the first function of changing the rotation speed of the motor based on the output of the current detection means, and at the same time, the rotation speed of the motor is changed based on the output of the rotation speed detection means. Since it has the second function of changing the rotation speed change area, for example, when used for a person with a strong beard, the change area is set at a place where the rotation speed of the motor is high,
When used for a person with a thin beard, it is possible to set a change region at a place where the rotation speed of the motor is low. By setting in this way, the number of rotations of the motor can be changed in accordance with the progress of the shaving in the range of the number of rotations of the motor which is optimum for a person with a dark beard or a person with a thin beard.

Further, the calculating means stores the data of the number of revolutions and rearranges the data in descending order or in descending order,
When the beard depth is determined from the data of the number of revolutions during shaving, the beard depth can be reliably determined even for the data of the number of revolutions that complicatedly varies depending on the shaving.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The electric shaver of the electric circuit shown in FIG. 3 comprises a motor 1 for driving a blade, a rotation speed detection circuit 2 for detecting the rotation speed of the motor 1, and a rotation control means 3 for controlling the rotation speed of the motor. , Current detection means 4 for detecting the load current of the motor 1
And an arithmetic circuit 5 for arithmetically operating the output signal of the current detecting means 4.

A hall element or the like is used for the rotation speed detection circuit 2, and a signal corresponding to the rotation speed of the motor 1 is input to the arithmetic circuit 5.

The rotation control means 3 includes a rotation control circuit 3A and
It is composed of a transistor 3B. Rotation control circuit 3
A adjusts the resistance between the collector and the emitter by the base current flowing through the transistor 3B. The resistance between the collector and the emitter of the transistor 3B changes, and the rotation speed of the motor 1 can be controlled. When the base current increases, the resistance between the collector and the emitter of the transistor 3B decreases.
When the resistance between the collector and the emitter decreases, the motor 1
The current increases and the rotation speed increases. On the contrary, when the base current decreases, the resistance between the collector and the emitter of the transistor 3B increases, the current of the motor 1 decreases, and the rotation speed decreases.

The current detecting means 4 converts a current detecting resistor 4A connected in series with the motor, an amplifier 4B for amplifying a voltage generated across the current detecting resistor 4A, and an output signal of the amplifier 4B into a digital quantity. It is provided with an A / D converter 4C. A voltage proportional to the load current of the motor 1 is generated across the current detection resistor 4A. Current detection resistor 4A
After the voltage generated at both ends of is amplified by the amplifier 4B,
The digital amount is converted by the A / D converter 4C. A /
The output signal of the D converter 4C is input to the arithmetic circuit 5.

The current detecting means for amplifying the voltage generated across the current detecting resistor 4A by the amplifier 4B and inputting it to the A / D converter 4C is characterized in that the current detecting resistor 4A can be made small. The A / D converter 4C uses the amplifier 4 at a constant cycle.
The output of B is converted into a digital amount and input to the arithmetic circuit 5. The arithmetic circuit 5 outputs a trigger pulse to the A / D converter 4C in order to determine the timing at which the A / D converter 4C converts the output of the amplifier 4B into a digital amount.

By the way, the arithmetic circuit 5 determines the number of rotations of the motor in consideration of three factors. The first factor is the magnitude of the current and its change value immediately before the rotation speed is changed. The second factor is the time that has elapsed since the start of shaving. The third factor is beard strength.

First, the first element will be described. The arithmetic circuit 5 determines the rotation speed in consideration of the difference ΔI between the current value I detected by the current detection means 4 which is the first element and the previous measured value, and rotates the signal corresponding to the rotation speed. Output to control means. Fuzzy inference is used as a means for selecting the optimum motor rotation speed from this load current.

The fuzzy inference based on the fuzzy rule table will now be described. The arithmetic circuit compares the measured value I of the load current with the reference value set in the arithmetic circuit. When the measured value is larger than the reference value, how large the measured value is is determined in the range of attributes 0 to 1. The attribute is 1 if it is sufficiently larger than the reference value. Similarly, the measured value I
Attributes 0 to 1 are used to judge an aggregate of which is almost equal to the reference value. Similarly, when the value is smaller than the reference value, the attributes 0
Judge within the range of 1.

On the other hand, the arithmetic circuit calculates the difference ΔI from the previous measured value.
, A group of negative, zero, and positive is judged in the range of attributes 0 to 1. For example, in Table 1, when the measured value I is larger than the reference value, the attribute is 1, and the difference ΔI from the previous measured value is positive and the attribute is 1, the arithmetic circuit is a fuzzy rule table. According to N (negative)
The signal of is output. The P signal indicates the rotation speed of the motor at 50 rp
It is an instruction to raise m. In this way, the fuzzy rule table defines the command when each attribute is 1.

Tables 1 to 3 are fuzzy rule tables in which the rules are changed according to the rotation speed of the motor. Table 1
Is a fuzzy rule table when the rotation speed of the motor is 7200 rpm or more.

[0022]

[Table 1]

Table 2 is a fuzzy rule table when the number of rotations of the motor is 6500 rpm or more and less than 7200 rpm.

[0024]

[Table 2]

Table 3 is a fuzzy rule table when the rotation speed of the motor is less than 6500 rpm.

[0026]

[Table 3]

The symbols used in Tables 1 to 3 are as follows. Rotation speed of PB (Positive Big) motor is 600r
Raise pm. P (Positive) Motor speed 300r
Raise pm. Z (zero) Keeps the motor speed constant. N (Negative) Motor rotation speed is 50 rp
lower by m. NB (Negative Big) Motor speed 150r
pm lower.

As described above, the arithmetic circuit determines the magnitude of the load current value I or the attribute of the difference ΔI from the previous measured value.
Fuzzy reasoning is used to change the rotation speed of the motor. That is, the arithmetic circuit determines to what degree the attributes of 1 match, and reflects the degree of agreement in the output signal to finely adjust the rotation speed of the motor.

Here, the reason why the amount of change (N, NB) for lowering the number of rotations of the motor is made smaller than that (PB, P) for raising is that the amount of beard is suddenly increased after shaving. This is to prevent the user from erroneously recognizing that the number of revolutions of the motor sharply decreases and the user suddenly decreases the capacity of the drive battery or malfunctions of the drive circuit.

Next, the second element will be described. In this electric shaver, the rotation speed of the motor is changed within a predetermined range based on the first element. Here, the arithmetic circuit 5 considers the second element,
After a certain period of time has passed from the start of shaving, the range in which the number of revolutions changes gradually decreases. In FIG. 4, the rotational speed is forcibly reduced to 500 rpm over 20 seconds after a fixed time. In this way, the arithmetic circuit 5 forcibly lowers the range in which the rotational speed changes by 500 rpm by the second factor after a certain time has elapsed.

Finally, the third element will be described. The arithmetic circuit 5 considers the third factor, the darkness of the whiskers. Here, FIGS. 5 to 7 show changes in the number of revolutions when a person with a thick beard and a person with a thin beard shave. Figure 5 shows a person with a dark beard evenly shaved over the face, Figure 6 shows a person with the same beard shaved the left and right sides of the face separately, and Figure 7 shows a person with a light beard evenly over the face. Shows the case of shaving. As these figures show, a person with a dark beard has a higher load than a person with a light beard, and therefore the number of rotations of the motor becomes high.
Further, as the shaving progresses, the load gradually decreases and the rotation speed decreases. In the case of FIG. 6, it is shown that the rotation speed becomes high again when the shave changes to the left and right of the face. As described above, the beard density is clearly represented by the number of rotations of the motor, and thus the beard density can be determined by detecting this number of rotations.

Therefore, the arithmetic circuit 5 includes the rotation speed detecting means 2
Data of the number of rotations of the motor detected by is input and the beard density is determined by calculating the data. Here, FIG. 8 is obtained by rearranging the data of the number of rotations of the motor shown in FIGS. 5 to 7 in descending order. According to this figure, it can be seen that there is a clear difference in the number of rotations between a person with a thick beard and a person with a thin beard.
Further, in the case of a person with a dark beard shown in FIGS. 5 and 6, it is understood that the same waveform can be obtained by rearranging the beards in the descending order even if the shaving method is different. By rearranging the beards in the descending order, it is possible to easily determine whether the beard is dark or light, and even if the beard is shaved differently, the beard depth can be easily determined. The arithmetic circuit 5 has a function of storing the data of the number of revolutions and rearranging the data in descending order, and accurately determines the whisker depth.

When the arithmetic circuit 5 determines the beard density, the arithmetic circuit 5 varies the range in which the rotational speed changes in accordance with the beard density.

That is, as shown in FIG. 4, for a person with a thin beard, the setting adjustment range of the rotational speed is lowered by 500 rpm after 1 minute and 2 minutes. For a person with a strong beard, the rotational speed is reduced by 500 rpm only after 2 minutes have passed. The setting range of the number of rotations of the motor shown in FIG.
Set between 7000 rpm. However, when used by a person with a thin beard, the setting adjustment range of the rotation speed is lowered by 500 rpm after 1 minute, and the rotation speed is adjusted to 8000 to 650.
The speed is set to 0 rpm, and further after 2 minutes, the speed is lowered by 500 rpm to be 7500 to 6000 rpm. When used by a bearded person, the rotation speed does not decrease after 1 minute. After 2 minutes, the setting adjustment range is lowered by 500 rpm to 8000 to 6500 rpm.

As described above, the arithmetic circuit 5 changes the setting adjustment range of the number of revolutions as a function of whisker density and time. This electric razor has a characteristic that it can be used in an ideal state because the rotation speed can be adjusted in a lower range as the shaving approaches the end. However, the electric shaver of the present invention does not necessarily need to lower the setting adjustment range as time passes. The setting adjustment range of the motor speed is changed between a person with a dark beard and a person with a thin beard,
It is also possible to set the same setting adjustment range from the beginning to the end of shaving. For example, when a person with a dark beard uses it, the setting adjustment range of the motor rotation speed is 6500 rpm to 8500 rpm from the beginning to the end, and when a person with a thin beard uses it, the setting adjustment range of the motor rotation speed is 600.
It is also possible to set 0 rpm to 8000 rpm. Further, it is possible to control the rotation speed of the motor by providing different fuzzy rule tables for a person with a thick beard and a person with a thin beard.

Based on the above three factors, the procedure for controlling the number of revolutions in this electric shaver that realizes optimum shaving will be described.

First, when the shaving is performed by turning on the switch of the electric razor, the rotation speed of the motor is adjusted while detecting the load current based on the fuzzy reasoning which is the first element. During this period, the arithmetic circuit stores the data of the rotation speed of the motor. When the switch is turned off after finishing the shaving, the arithmetic circuit sorts the stored data of the number of revolutions in descending order, and then determines the darkness of the beard. When the beard darkness is determined, the range in which the rotation speed is changed is set according to the determined beard darkness. Next, when the switch is turned on to shave, the number of revolutions is controlled within the range of the number of revolutions set for the previous shaving. The above is repeated by turning the switch on and off. Therefore, the beard depth is determined for each shave, and the range in which the rotation speed is changed is set again. However, the beard thickness is not determined by one shaving, but the beard thickness is determined by averaging the waveforms of the shaving rotation speeds several times. By doing so, it is possible to further improve the accuracy of the determination of beard darkness.

[0038]

According to the present invention, the rotation speed control means is
Since it has the first function of changing the rotation speed of the motor based on the output of the current detection means, and has the second function of changing the rotation speed change region of the motor based on the output of the rotation speed detection means. , For example, when used for a person with a dark beard, set the change area at a high motor rotation speed, and for a person with a thin beard, set a change area at a low motor rotation speed. Something like that is possible. By setting in this way, the number of rotations of the motor can be changed in accordance with the progress of the shaving in the range of the number of rotations of the motor which is optimum for a person with a dark beard or a person with a thin beard.

Further, the calculating means stores the data of the number of revolutions and rearranges the data in the descending order,
When the beard depth is determined from the data of the number of revolutions during shaving, the beard depth can be reliably determined even for the data of the number of revolutions that complicatedly varies depending on the shaving.

Therefore, the electric razor according to the present invention has a feature that both a person with a thick beard and a person with a thin beard can control the number of revolutions of the motor to be in an optimum state for himself and can comfortably and neatly shave. That is, a person with a thick beard can use it in a sharp and sharp state, and a person with a thin beard can use it with less tingling. A person with a strong beard has stronger skin than a person with a thin beard, so even if the number of rotations is increased, it is less irritating and can be used in a refreshing state with a sharp sharpness. Since many people with thin beards have weak skin, there is a feature that the skin is prevented from being scratched by lowering the rotation speed of the motor, and the beard can be attracted well to shave cleanly.

[Brief description of drawings]

FIG. 1 is a graph showing a current waveform of a motor when shaving.

FIG. 2 is a graph showing a state in which the rotation speed of a conventional electric shaver motor is changed.

FIG. 3 is a block circuit diagram of an electric shaver showing an embodiment of the present invention.

FIG. 4 is a graph showing a state in which the electric shaver according to the embodiment of the present invention changes the setting adjustment range of the motor rotation speed with time.

FIG. 5 is a graph showing a rotation speed waveform of a motor when a person with a dark beard evenly shaves the entire face.

FIG. 6 is a graph showing a waveform of the number of rotations of a motor when a person with a strong beard has a shave on the left and right sides of the face separately.

FIG. 7 is a graph showing a rotation speed waveform of a motor when a person with a thin beard evenly shaves the entire face.

FIG. 8 is a graph in which the rotation speed waveforms of FIGS. 5 to 7 are rearranged in descending order of rotation speed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 motor 2 rotation speed detection circuit 3 rotation control means 3A rotation control circuit 3B transistor 4 current detection means 4A current detection resistor 4B amplifier 4C A / D converter 5 arithmetic circuit

Claims (2)

[Claims] 1. A motor for driving a blade, a current detection means for detecting a load current of the motor, a rotation speed detection means for detecting a rotation speed of the motor, and the motor based on an output of the current detection means. Rotation speed control means having a second function of changing the rotation speed change region of the motor based on the output of the rotation speed detection means. An electric razor characterized by that. 2. The electric shaver according to claim 1, further comprising arithmetic means for storing the data of the number of revolutions detected by the number of revolutions detecting means, and rearranging the data in the descending order.