JPH05317538A - Electric razor whose number of revolution is controlled in accordance with whiskers - Google Patents

Abstract

PURPOSE:To constitute the electric razor so that shaving can be executed sharply, and by decreasing smarting, to a person whose whiskers are thick, and a person whose whiskers are thin, respectively. CONSTITUTION:The electric razor is provided with a motor for driving a blade, a rotation control means of the motor, a current detecting means of the motor, and an arithmetic circuit for operating an output signal of the current detecting means. The arithmetic circuit is constituted so that thickness of whiskers is operated, and a set adjustment range of the number of revolution of the motor is varied in accordance with thickness of whiskers. In such a way, thickness of whiskers is decided, the set adjustment range of the number of revolution of the motor is changed, and in the case of a person whose whiskers are thin, the number of revolution is lowered, and in the case of a person whose whiskers are thick, the number of revolution is heightened, and the motor can be rotated in an optimal state to thickness of whiskers.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric razor for controlling the number of rotations of a motor so as to optimize the shaving.
In particular, the present invention relates to an electric razor capable of optimally shaving from a person with a thick beard to a person with a thin beard.

[0002]

2. Description of the Related Art An electric shaver that does not control the rotation speed of a motor has a property that the rotation speed increases when there is no load and decreases when a load is applied. This electric razor rotates the motor at high speed when there is no load and consumes unnecessary power. Unnecessary power consumption can be prevented by reducing the unloaded rotation speed. To achieve this, an electric shaver that controls the rotation speed of a motor has been developed (Japanese Patent Laid-Open No. 62-79084). The electric shaver described in this publication has a motor rotation speed detecting means. The rotation speed detection means controls the rotation control means of the motor to keep the rotation speed of the motor constant.

This electric razor can prevent wasteful power consumption with no load. However, it is not possible to adjust the number of rotations to an optimum value according to the strength of the beard of the user. Since the motor is driven at a constant rotation speed, a person with a thin beard has too high a rotation speed to attract the beard. In addition, there is a problem that after a shave, a tingling easily occurs. In addition, when used by a person with a strong beard, the hair is kept rotating at a constant speed during shaving, and thus, when the shaving progresses, similarly, the attraction may be worsened or a tingling may occur.

The present inventor has further developed an electric shaver in which the number of revolutions of the motor is changed according to the state of the shaving, for the purpose of solving this drawback (Japanese Patent Application No. 3-45).
No. 28). This electric razor detects the load current of the motor and controls the rotation speed. When the load current of the motor becomes low, the rotation speed of the motor is reduced. The load current of the motor decreases as the blade cuts the whiskers less. Therefore, the rotation speed of the motor decreases as the shaving progresses. When the number of rotations of the motor decreases, the beard is better attracted and you can shave cleanly. In addition, it is possible to reduce the sticking. This electric razor has the feature that the rotation speed of the motor is first increased to sharply "roughly scrape" and finally the rotation speed is lowered to the "finished sled" state.

[0005]

The electric shaver of this structure detects the load current of the motor and controls the rotation speed of the motor immediately after that. At first, the blade cuts many whiskers, so the load current of the motor is large and the rotation speed of the motor is increased. As the shaving progresses, the number of whiskers that the blade cuts decreases and the rotation speed of the motor decreases. However,
When actually using an electric razor, the entire face is not shaved at the same time. By partially repeating the rough shaving and the finishing shaving, the shaving of the entire face is completed.

FIG. 1 shows the load current of the motor when shaving. As shown in this figure, the load current gradually increases and decreases. Therefore, the number of rotations of the motor also increases and decreases and gradually decreases. FIG. 2 shows a state in which the rotation speed of the motor changes. As shown in this figure, the rotation speed of the motor is changed within a certain range. Figure 2 shows the motor speed of the electric razor as 600
It is controlled in the range of 0 rpm to 7500 rpm.

[0007] This electric razor makes the shaving progress, so that the number of rotations is reduced, so that it is possible to improve the attraction of the shaving and the beard, but when used by a person with a thick beard, the sharpness is lacking. If used by a person with a thin beard, tingling may occur. In particular, if the number of rotations is adjusted according to a person with a thick beard, there is a drawback that the person with a thin beard is more likely to get caught, and if a person with a thin beard is used, the sharpness of the person with a darker is further deteriorated.

The present invention was further developed with the object of resolving this drawback, and an important object of the present invention is that the number of rotations is increased by a beard that allows both a person with a strong beard and a person with a thin beard to shave in an optimum state. It is in providing a controlled electric razor.

[0009]

The device of the present invention has the following constitution in order to achieve the above-mentioned object. That is,
The electric shaver whose rotation speed is controlled by the whiskers of the present invention is a motor for driving a blade, a rotation control means for controlling the rotation speed of the motor, a current detection means for detecting a load current of the motor, and a current detection means. And an arithmetic circuit for arithmetically operating the output signal of.

The arithmetic circuit calculates the beard depth, and changes the setting adjustment range of the motor rotation speed according to the beard depth.
When used by a person with a strong beard, increase the motor speed setting adjustment range. If used by a person with a thin beard, lower the motor speed setting adjustment range. The whisker density can be calculated, for example, from the average value of the load current of the motor once to a plurality of times. As shown in FIG. 3, the load current waveform (B) of a person with a dark beard and the load current waveform (A) of a person with a light beard are different, and the current waveform of a person with a dark beard is compared to that of a person with a light beard. This is because the average value of the current becomes large.

[0011]

The electric shaver of the present invention adjusts the setting adjustment range of the motor rotation speed by judging the beard thickness of the user. The whisker density is calculated by the arithmetic circuit by analyzing the current waveform when the whisker is used once to several times. The setting adjustment range for changing the motor speed is changed depending on the whiskers. When used for a person with a strong beard, the setting adjustment range of the motor speed is controlled to be high. When used for a person with a thin beard, the setting adjustment range of the motor speed is controlled low.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. However, the examples shown below are examples of the electric shaver for embodying the technical idea of the present invention, the electric shaver of the present invention, the material of the component, the shape,
The structure and arrangement are not specified in the structure below. The electric shaver of the present invention can be variously modified within the scope of the claims.

The electric shaver of the electric circuit shown in FIG. 5 includes a motor 1 for driving the 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. The motor 1 includes a current detection unit 4 that detects a load current and a calculation circuit 5 that calculates an output signal of the current detection unit 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,
It is composed of a transistor 3B. The rotation control circuit 3A controls the base current of the transistor 3B to control the rotation speed of the motor 1. The rotation control circuit 3A adjusts the resistance between the collector and the emitter by the base current flowing through the transistor 3B. Transistor 3B
The resistance between the collector and the emitter of the motor 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 current of the motor 1 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 amount. 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. The voltage generated across the current detection resistor 4A is amplified by the amplifier 4B and then converted into a digital amount by the A / D converter 4C.
The output signal of the A / 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 has a feature that the current detecting resistor 4A can be made small. The A / D converter 4C converts the output of the amplifier 4B into a digital amount at a constant cycle and inputs the digital amount to the arithmetic circuit 5. The arithmetic circuit 5 inputs 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.

The arithmetic circuit 5 is composed of a microcomputer. The arithmetic circuit 5 processes the signal input from the current detecting means 4 to determine the rotation speed of the motor 1. When the motor 1 is loaded, the current increases. The load current of the motor increases in proportion to the amount of whiskers. FIG. 3 shows the load current with a dark beard and a light beard. Curve B shows the load current when dark shaving and curve A shows the load current when thin shaving. In this way, the output signal of the current detecting means corresponds to the amount of whiskers, which enables the amount of whiskers to be detected.

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

The arithmetic circuit 4 has a difference ΔI between the current value I detected by the current detecting means, which is the first element, and the previous measured value.
The rotation speed is determined in consideration of the above, and a signal corresponding to the rotation speed is output to the rotation control means.

Here, the fuzzy inference based on the fuzzy rule table will be described. The arithmetic circuit compares the measured value I of the load current with a reference value set in the arithmetic circuit. As a result, when the measured value is larger than the reference value,
It is judged how large it is in the range of attributes 0 to 1. The attribute is 1 if it is sufficiently larger than the reference value. Similarly,
Attribute 0 to the aggregate of measured values I almost equal to the reference value
Judge with 1. Further, when the value is smaller than the reference value, the judgment is similarly made within the range of attributes 0 to 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 in the fuzzy rule table. Therefore P (positive)
The signal of is output. P signal is the number of rotations of the motor is 300
It is an instruction to increase the rpm. In this way, the fuzzy rule table defines the command when each attribute is 1.

Tables 1 to 3 are fuzzy rule tables whose rules are changed according to the number of rotations of the motor. Table 1 is a fuzzy rule table when the rotation speed of the motor is 7200 rpm.

[0024]

[Table 1]

Table 2 shows that the motor speed is 6500 rpm.
It is a fuzzy rule table in the case of above 7200 rpm.

[0026]

[Table 2]

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

[0028]

[Table 3]

The symbols used in Tables 1 to 3 are as follows. PB (Positive big) Increase the motor speed by 600 rpm P (Positive) Increase the motor speed by 300 rpm Z (Zero) Keep the motor speed constant N (Negative) Decrease the motor speed by 50 rpm NB (Negative big) ) Lower the motor speed by 150 rpm

As described above, the arithmetic circuit uses the fuzzy inference to change the rotation speed of the motor according to the magnitude of the load current value I or the attribute of the difference ΔI from the previous measured value. 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 number of rotations of the motor.

The reason why the amount of change for lowering the number of revolutions of the motor is made smaller than that for raising it is that the amount of beard is sharply reduced after shaving and the number of revolutions of the motor is drastically reduced. This is to prevent the user from erroneously recognizing that the capacity of the drive battery is suddenly reduced or the drive circuit malfunctions.

Further, in consideration of the second factor, the arithmetic circuit 5 gradually reduces the rotation speed after a certain period of time has passed since the start of shaving. In FIG. 4, the rotation speed is forcibly reduced to 500 rpm over 20 seconds after a fixed time. After the elapse of a certain time, the arithmetic circuit 5 causes the second element to
The rotational speed determined by the first factor is forcedly reduced to 500 rpm. In the control shown in this figure, the setting adjustment range for adjusting the rotational speed of the motor is changed in consideration of the third element, the darkness of the whiskers. A person with a light beard lowers the rotation speed by 500 rpm after 1 minute and after 2 minutes, and a person with a dark whiskers lowers the rotation speed by 500 rpm only after 2 minutes. The setting range of the motor rotation speed shown in this figure is initially 8
It is set between 500 rpm and 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 one minute,
500 rpm to 8000 rpm, further lowering 500 rpm after 2 minutes, 6000 rpm to 750 rpm
It is set to 0 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 6500 rpm-800.
Set to 0 rpm.

The arithmetic circuit for controlling as shown in FIG. 4 gradually decreases the setting adjustment range of the rotation speed of the motor depending on the whisker density as a function of time. in this way,
An electric razor that changes the setting adjustment range of the number of revolutions as a function of the beard density and time can adjust the number of revolutions lower as the shaving approaches the end,
It has the feature that it can be used under ideal conditions. However, the electric shaver of the present invention does not necessarily need to lower the setting adjustment range as time passes. Although the person with a thick beard and the person with a thin beard change the setting adjustment range of the motor rotation speed,
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 beard is used, the setting range of the motor rotation speed is set to 6500 rpm to 8500 rpm from the beginning to the end.
It is also possible to set it to 000 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.

The arithmetic circuit 5 calculates the current waveform when shaving once to determine the darkness of the user's whiskers. 1
When the error is large in the measurement of one time, the density of the whiskers is judged from the current waveform which is shaved several times. When used by people with different beard thickness, the waveform of the load current of the motor changes as shown in FIG. When used by a bearded person, it takes time for the current to drop, as shown by curve B. The current drops quickly as shown by curve A because the shave ends early when used by a thin person. Therefore, the beard density of a person who uses the electric razor can be determined by the arithmetic circuit by averaging the currents when the shaving is performed once or several times.

[0035]

According to the electric shaver of the present invention, the number of rotations of which is controlled by the beard, the darkness of the beard is detected, and the setting adjustment range for changing the number of rotations is changed between a person with a thick beard and a person with a thin beard. There is. That is, a person with a thick beard changes the rotation speed of the motor in a high rotation speed range, and a person with a thin beard changes the rotation speed of the motor in a low rotation speed range. Therefore, the electric razor of 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 rotations 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 thick beard has stronger skin than a person with a thin beard.
It can be used in a magnificent state as a sharp sharpness. In addition, since people with a thin beard often have weak skin, there is a feature that the rotation of the motor is lowered to prevent skin from being scratched, 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 razor motor changes.

FIG. 3 is a graph showing the load current of the motor when used by a person with a thick beard and a person with a thin beard.

FIG. 4 is a graph showing a state where 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 block diagram showing an electric circuit of an electric shaver showing an embodiment of the present invention.

[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 resistance 4B ... Amplifier 4C
… A / D converter 5… Arithmetic circuit

Claims (1)

[Claims] 1. A motor for driving a blade, a rotation control means for controlling a rotation speed of the motor, a current detection means for detecting a load current of the motor, and an output signal of the current detection means to calculate a load of the motor. In an electric shaver that is configured to change the rotation speed of the motor within a set adjustment range depending on the load of the motor, the calculation circuit calculates the thickness of the whiskers and the thickness of the whiskers A beard characterized by changing the speed adjustment range to control the motor speed setting adjustment range for a person with a thin beard to be lower than the motor speed setting adjustment range for a person with a dark beard. Electric razor whose rotation speed is controlled by.