JP4663904B2 - Electric razor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a small electric device such as an electric razor, and particularly to a device having a function for detecting the magnitude of a load.
[0002]
[Prior art]
Conventionally, in this type of small electrical equipment, the rotational speed of the motor is changed by increasing / decreasing the magnitude of the DC voltage applied to the motor, while the load current corresponding to the magnitude of the load applied to the motor is changed. Proposals have been made that make it possible to detect the magnitude of a load by utilizing the change in size (see, for example, JP-A-5-38387 and JP-A-5-200168).
[0003]
[Problems to be solved by the invention]
By the way, when the motor is driven with a DC voltage as described above, since the value of the motor current in a steady state when no load is applied is stable, the motor current caused by the application of the load is not It is not difficult to detect the increase.
[0004]
However, when the motor is pulse-driven, even before the load load is applied, the motor current itself exhibits a fluctuation corresponding to the duty ratio of the driving voltage. It is difficult to detect the load fluctuations separately because they overlap.
[0005]
On the other hand, it is also possible to integrate the change in motor current and compare the averaged detection voltage with the comparison value. However, the motor drive voltage duty ratio is small and large, with respect to load load fluctuations. As a result of the difference in the fluctuation ratio of the detection voltage, it is difficult to set the comparison voltage.
[0006]
The present invention has been made in view of such inconvenience, and by changing the reference for detection in accordance with the magnitude of the duty ratio of the drive voltage, the load can be maintained while maintaining a relatively simple configuration. It is an object of the present invention to provide a small electric device that can detect a size without erroneous detection and can accurately execute a control operation corresponding to the detection operation.
[0007]
[Means for Solving the Problems]
The small electrical device according to the present invention has a duty ratio in the applied voltage in conjunction with the application of a DC voltage output from a DC power source 71 such as a secondary battery, as shown in FIG. Corresponding to the change as illustrated in FIG. 10, the driving means 72 operating at a predetermined speed is provided.
[0008]
Furthermore, a load current detection means 73 that can output a detection signal that changes in accordance with the magnitude of the load current flowing through the drive means 72, a detection signal detected by the load current detection means 73, and a preset comparison signal Comparing means 74 that compares the magnitude of S and enables a predetermined determination operation corresponding to the magnitude relationship between the two and control means 75 that can change the duty ratio of the voltage applied to the driving means 72 is provided. .
[0009]
In the present invention, a plurality of sets of comparison signals S1, S2,... Are provided, while the comparison unit 74 corresponds to the difference in duty ratio of the applied voltage used to drive the drive unit 72. The comparison operation is performed by changing the comparison signal S.
[0010]
Here, the driving means 72 is a direct current motor, and the load current detecting means 73 further includes a resistor 76 interposed in series with the driving means 72 and an integrating means 77 for integrating the voltage extracted from both ends of the resistor 76. It consists of and.
[0011]
The above-described comparison signals can be two sets of S1 and S2, and each set of comparison signals can be further composed of one or a plurality of comparison voltages. In that case, the load current detecting means 73 is illustrated in FIG. 11B, which has a relatively large voltage fluctuation corresponding to the intermittent application of the voltage applied to the driving means 72 by setting the time constant in the integrating means 77. The detection voltage range and the detection voltage range with relatively small voltage fluctuations as shown in FIG. 11 (a) are provided, and the comparison signal switching in the comparison means 74 is made large or small in the voltage fluctuation ratio of the detection voltage. Can be done correspondingly.
[0012]
In the control means 75 described above, on / off control of the switching means 78 is performed by applying a drive signal whose duty ratio changes in a plurality of stages to the switching means 78 connected in series with the drive means 72, and the operation of the drive means 72. The speed can be changed in a plurality of stages, and the comparison signal used in the comparison operation is determined in accordance with the change in the duty ratio in the drive signal.
[0013]
Further, the control means 75 described above can automatically change the duty ratio of the drive signal in accordance with the determination operation content in the comparison means 74. Further, in conjunction with the switching operation of the operation means 79 such as a push button switch, it is possible to switch between the above-described automatic drive signal change and manual change.
[0014]
The motor of the driving means 72 drives the inner blade of the electric razor. The control state display means 80 displays the speed change of the driving means 72 in stages, and whether the control state of the control means 75 is automatic or manual. It is preferable that a control content display unit 81 for displaying the difference is further provided, and the control state display unit 80, the control content display unit 81, and the operation unit 79 are arranged close to each other in a line.
[0015]
【The invention's effect】
As described above, the present invention changes the reference for detection according to the duty ratio of the drive voltage, thereby maintaining a relatively simple configuration without erroneously detecting the size of the load. It can be detected, and the control operation corresponding to the detection operation can be accurately executed.
[0016]
Furthermore, by detecting the load with the voltage generated at both ends of the resistor 76 connected in series with the driving means 72 by the integrating means 77, the detection corresponding to the load load can be accurately performed.
[0017]
In addition, the determination of the magnitude of the load current is performed based on two types of criteria, which are compared with an average value in a range where the level fluctuation is small and compared with a peak value in a range where the fluctuation is large. Differences in fluctuations can be accurately separated and detected.
[0018]
Further, the driving means 72 is configured such that the speed is changed by the driving signal output from the control means 75 and the comparison signal to be used corresponding to the change of the driving signal is determined. The load current detection operation is performed without detecting the operation speed of the means 72.
[0019]
Further, by performing control to increase / decrease the operating speed of the driving means in accordance with the detected load load, for example, when shaving, an inner blade speed corresponding to the density of the heel is automatically obtained. .
[0020]
Further, since the control state display means 80, the control content display means 81, and the operation means 79 are arranged close to a single line state, the mode switching operation by the operation means 79 is accurately performed while observing the clearly displayed control state. Can be done.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a small electric apparatus according to the present invention will be described based on an example implemented in a rotary electric shaver illustrated in FIG. 2, but the present invention is not limited thereto, and an electric shaver in which an inner blade rotates in a reciprocating manner or around a vertical axis. Of course, the present invention can be applied to various small electric devices such as a massager, an electric toothbrush or a nail brush having a function of controlling the operation speed of a driving part such as a motor or vibrator.
[0022]
As shown in FIG. 2, the electric razor 10 is provided with a head part 13 that accommodates the inner blade 12 and is open at the upper end position of the main body case 11 so as to be swingable, and further closes the opening in the head part 13. An outer blade holder 15 having a mesh blade-shaped outer blade 14 in contact with the inner blade 12 is disposed.
[0023]
The inner blade 12 has a cylindrical shape with a spiral blade portion on its peripheral surface. The inner blade 12 extends from the opposite ends of the rotating shaft 16 outwardly to support it horizontally above the head portion 13 and rotates one of them. The shaft 16 and the rotating shaft of the motor 17 are connected by a reduction mechanism comprising a plurality of gears or timing belts (not shown).
[0024]
On the front side of the main body case 11, a main switch 19 for controlling on / off of the motor 17 and a driving speed of the motor 17 are displayed on an operation panel 18 that vertically cuts in the center portion and extends in a narrow strip shape in the vertical direction. A first display unit 21 including three light emitting elements 20a, 20b, and 20c, a second display unit 22 for displaying the driving mode of the motor 17, and a sub switch for changing the driving state of the motor 17 23 and the third display unit 24 for displaying the charging time are arranged in a line, and the fourth display unit 25 surrounds the operation panel 18 and can display the remaining battery capacity as shown in FIG. Is provided.
[0025]
A socket 28 is provided at the lower end position of the main body case 11 so that the plug 27 of the charging adapter 26 can be removably connected. The electronic circuit 31 shown in FIG. 4 housed in the main body case 11 uses a commercial AC power source. So that it can be driven.
[0026]
The charging adapter 26 rectifies the commercial AC voltage 30 of about 100 to 250 V input through the power plug 29 by an inverter circuit (not shown) having a configuration substantially similar to that of the conventional battery, and then rectifies the secondary battery 36. A DC low voltage charging voltage Vd of about 4 V, for example, which is slightly higher than the terminal voltage Ve can be output.
[0027]
As the main switch 19 and the sub switch 23, for example, a push-type normally open switch is used, and the electronic circuit 31 performs a preset operation to be described later every time a pressing operation is performed.
[0028]
The first to third display units 21, 22, 24 separate one or a plurality of light emitting elements whose driving voltage is lower than the battery voltage, such as red light emitting diodes, and make their display shapes or display colors different. Thus, a predetermined display operation described later can be performed by changing the lighting position or blinking state of the light emitting elements.
[0029]
More specifically, the colors of the three light emitting elements 20 in the first display unit 21 are all set to yellow, the second display unit 22 is set to green, and the third light emitting unit 24 is set to red. In this way, by changing the display colors in the first display unit 21 and the second display unit 22, the movement of the first display unit 21 can be seen with reference to the second display unit 22. Can be quickly determined visually. This is particularly useful when the display on the first display unit 21 is not individually lit but the rotational speed is displayed by increasing or decreasing the number of lighting.
[0030]
On the other hand, as shown in FIG. 3B, the fourth display unit 25 uses a light emitting element 32 such as a blue LED, and does not directly emit output light, but includes a prism 33. The light is emitted from the light diffusion plate 35 disposed in close contact with the front side of the light guide plate 34 to the outside of the main body case 11 while being bent in a right angle direction and inputted to the lower end of the light guide plate 34. It is configured so as to emit light in a shape.
[0031]
Further, in this embodiment, the light diffusing plate 35 is exposed in a thin strip around the operation panel 18 described above, and the intensity of the light 61 output from the light diffusing plate 35 covers the entire surface. By setting the light incident on the light guide plate 34 to be attenuated as it travels upward, the fourth display unit 25 is the darkest as the lower end is brightest and goes upward when the light emitting element 32 is turned on. The light is emitted in a substantially U shape as shown in FIG.
[0032]
Next, the electronic circuit 31 housed in the main body case 11 is a one-chip type with a secondary battery 36 that can be charged and discharged a plurality of times as a drive source, as schematically shown in FIG. The whole is controlled by the microcomputer device 37, and a charge control unit 38 that regulates the charging timing for the secondary battery 36 and a display corresponding to the remaining battery level during driving by the secondary battery 36 are enabled. The battery remaining amount detection unit 39 and a motor control unit 40 that can change the driving state of the motor 17 are configured.
[0033]
The microcomputer device 37 used in the present invention is a general-purpose device having a plurality of analog voltage input ports by integrating a function as an A / D converter and is housed in a ROM inside. According to the program, the control operation corresponding to the change of the input analog voltage value can be performed only by the microcomputer device 37 without using individual parts such as an A / D converter and a comparator.
[0034]
That is, the voltage value input to the analog signal input port is compared with the divided voltage value of the reference voltage VS stabilized by the constant voltage circuit 41 and converted to a predetermined digital value of about 8 bits. The digital values are appropriately compared, and a predetermined calculation operation is performed according to the magnitude. Then, using the A / D conversion function provided in the microcomputer device 37 and the calculation function by the program, various types of detection and display or control operations corresponding to the detection contents are performed.
[0035]
The secondary battery 36 is a nickel metal hydride battery, and in the present embodiment, by connecting two batteries in series, the terminal voltage Ve becomes 1.8 V to 3 with the charge from the completely discharged state. Those that change to about 5V are used. However, it goes without saying that the type or number of batteries can be changed.
[0036]
As shown in FIG. 5, the charge control unit 38 receives the charge voltage Vd output from the charge adapter 26 via the first transistor 42 provided for switching and the temperature fuse 43 that blows when overheated. By applying to both ends of the secondary battery 36, the secondary battery 36 can be charged.
[0037]
That is, when the charging voltage Vd is input, the second transistor 44 connected to the base terminal of the first transistor 42 is first turned on, and the first transistor 42 is further turned on to start charging the secondary battery 36. At the same time, the light emitting element 45 provided in the third display unit 24 is energized to display that it is being charged.
[0038]
When the charging completion time is further reached, the microcomputer device 37 turns on the third transistor 46. As a result, the second transistor 44 and the first transistor 42 are turned off, and the charging of the secondary battery 36 is stopped. The current supply to the light emitting element 45 is also stopped to inform the operator that the charging is completed.
[0039]
Here, the method for detecting the full charge timing of the secondary battery 36 is not particularly limited. However, in the present embodiment, the battery voltage detection unit 47 that divides the battery voltage Ve is utilized by utilizing the fact that the terminal voltage Ve at the time of charging the nickel metal hydride battery changes as illustrated in FIG. A voltage proportional to the battery voltage Ve is input to the microcomputer device 37 and the change in the voltage is detected, so that the terminal voltage Ve of the secondary battery 36 reaches the peak value Vp, and further a predetermined voltage ΔV. Basically, it is determined that the time B at which the terminal voltage Ve decreases is at the time of full charge, and rapid charge is stopped.
[0040]
Further, in consideration of the case where the peak value Vp cannot be detected due to deterioration of the secondary battery 36, etc., a maximum charging time of about 1 hour is set in advance by the timer function in the microcomputer device 37, and the peak position is determined from the start of charging. If the longest charging time elapses without detection, charging is forcibly stopped.
[0041]
At the same time, the surface temperature of the secondary battery 36 is detected by the battery temperature detection circuit 49 using the thermistor 48, and after the temperature reaches the set value, for example, the set temperature is higher than the set temperature for about 10 seconds. Even when it is confirmed that the battery has been sustained, it is determined that the battery has been fully charged, and charging is stopped to prevent overcharging.
[0042]
Note that an AC detection unit 63 including a transistor 62 that is turned on when the charging voltage Vd is input is provided so that the input timing of the charging voltage Vd can be determined, and is used during various control operations including the above-described charging control.
[0043]
Next, the remaining capacity detection and display of the secondary battery 36 utilizes the fact that the terminal voltage Ve decreases as the secondary battery 36 is used as illustrated in FIG. Is determined to be in a fully charged state until time C when the terminal voltage Ve reaches the first comparison value V1, and the light emitting element 32 in the fourth display unit 25 is always turned on to display a full charge.
[0044]
Further, until the terminal voltage Ve falls below the first comparison value V1 and reaches the second comparison value V2, the light emitting element 32 is slowly blinked at intervals of about 1 second to display a charge notice display. When the voltage falls below V2, a display control operation is performed to shift to a charging prompt display that shortens the blinking cycle.
[0045]
In order to realize the above-described operation, in this embodiment, as shown in FIG. 7, the voltage stabilized by the constant voltage circuit 41 is used as the reference voltage VS at the time of A / D conversion, and this voltage is further compared to the comparison voltage generation circuit. By dividing the voltage at 50, the first comparison value V1 and the second comparison value V2 are formed.
[0046]
At the same time, the secondary battery voltage Ve is divided by the battery voltage input circuit 51 and input to the microcomputer device 37, and the present battery remaining amount is determined by comparing the input value with the comparison values V1 and V2. The determination result is displayed on the fourth display unit 25.
[0047]
In the present embodiment, a light emitting element having a driving voltage higher than the terminal voltage Ve of the secondary battery 36, such as a blue LED, is used as the light emitting element 32 provided in the fourth display unit 25.
[0048]
Therefore, the terminal voltage Ve of the secondary battery 36 is once increased to a voltage necessary for display on the fourth display unit 25 by the booster circuit 52 and then applied to the light emitting element 32. Further, since the current flowing through the light emitting element 32 on the fourth display unit 25 side is larger than the current flowing through the light emitting element on the first to third display units 21, 22, 24 side, the switching circuit 53 is connected in series with the light emitting element 32. By interposing and controlling the switching circuit 53 with the microcomputer device 37, the display time on the fourth display unit 25 can be regulated.
[0049]
Further, the battery remaining capacity display operation in the fourth display unit 25 can be basically executed during an arbitrary period, including during the ON period of the motor 17. Particularly during the ON period of the motor 17, it also serves as a pilot lamp that indicates that the motor 17 is being driven.
[0050]
However, as shown in FIG. 8E, the terminal voltage Ve of the secondary battery 36 continues to decrease from the time t1 to the time t2 during the driving of the motor 17, but the terminal voltage Ve returns as the driving of the motor 17 stops.
[0051]
Therefore, in this embodiment, as shown in FIGS. 8A and 8B, switching is performed as shown in FIG. 8D when the motor driving is stopped at time t2 after the motor driving is started at time t1. The circuit 53 is turned off, and the remaining capacity display operation in the fourth display unit 25 is temporarily stopped until time t3.
[0052]
On the other hand, during the remaining capacity display stop period T1 from time t2 to t3, the battery remaining capacity detection operation continues as shown in FIG. 8C, and the remaining capacity at time t3 is maintained. Then, after the display corresponding to the retained remaining capacity is performed on the fourth display unit 25 during the period T2 from the time t3 to the time t4, the display on the fourth display unit 25 is stopped.
[0053]
For example, in the case of an electric razor, as a result of accumulation of lint between the outer blade 14 and the inner blade 12 and an increase in load, a display indicating that the remaining battery capacity is low despite the battery capacity being sufficient is performed. The user may repeat charging. Even in such a case, it is possible to accurately check whether or not the battery capacity actually remains by detecting and displaying the remaining capacity after the energization of the motor 17 is stopped.
[0054]
It should be noted that the period T1 during which the display is stopped after the motor is stopped is the minimum necessary, for example, 0. 0, for confirming that the battery voltage is restored and separately expressing the state before and after the motor 17 is stopped, as shown in FIG. Although it is preferable to set it for a short time of about 2 to 1 second, of course, it can set arbitrarily.
[0055]
For example, when a time of 0.2 seconds or less is set, the battery voltage recovery is insufficient during that time, so the battery voltage recovery rate is measured, and the final recovery voltage is determined from the measured value. To estimate the remaining capacity. At the same time, the display indicating that the remaining battery level is being detected is of a simple and easy-to-recognize type such as simply stopping the display or changing the color because the setting time is short.
[0056]
On the contrary, when the display stop period is a long time such as 1 second or longer, blinking of the light emitting element 32, change of the light emission color, or warning display is performed to indicate that the remaining battery capacity is being detected during that period. As a result, the driving of the motor 17 is completely stopped, and the operator can be more accurately recognized that the remaining charge detection operation is normally performed.
[0057]
In this case, the display performed during the remaining amount display stop period can be provided with a separate display unit, or can be executed using the fourth display unit 25. In short, the display contents are changed by changing the display contents during driving of the motor 17 and immediately after the stop of driving, for example, changing the display contents to the stop display if the display before that is blinking, and changing to the blinking display if the display is lit. Can be confirmed. Of course, the display means, the display method, and the display contents can be appropriately changed and implemented as long as they fulfill that role.
[0058]
In addition, the display on the fourth display unit 25 is made to increase or decrease the light emission intensity instead of turning on or blinking one light emitting element as described above, or a plurality of light emitting diodes are provided to correspond to the increase or decrease of the remaining capacity. Thus, the number of lighting of the light emitting elements can be increased or decreased. In addition, instead of displaying the increase / decrease of the number of lighting by the light emitting diode, other display means such as a liquid crystal display panel or EL element is used, and the remaining capacity is displayed by a numerical value such as the number of possible shavings. Can change.
[0059]
However, in any of the display methods described above, immediately after the energization of the motor 17 is stopped, the remaining amount display is temporarily turned off for a predetermined time T1, and then the content detected during the display off period is displayed again for a predetermined time T2. The display is the same as described above.
[0060]
It is also possible to store the remaining capacity immediately before the main switch 19 is turned off and display the stored remaining capacity during the post-stop display period T2 performed after the display stop period T1. In this case, the stop display period T1 can be set short, and the remaining amount display can be resumed immediately after being turned off.
[0061]
Next, as shown in FIG. 9, the motor control unit 40 pushes the sub switch 23 to change the rotation speed of the motor 17 to, for example, a high speed of about 8800 revolutions per minute and a medium speed of about 8300 revolutions per minute. In addition to the “manual mode” that can be changed in three stages at a low speed of about 7800 revolutions per minute, a change in load load applied to the motor 17 is detected, and the rotation speed of the motor 17 is adjusted in accordance with the load change. The “automatic mode” that enables automatic change in three stages of manual operation is provided.
[0062]
The motor 17 used here is a DC type that drives the inner blade 12 to rotate. When the rotation speed is determined by the magnitude of the average voltage applied to the motor 17 and the applied voltage is constant, The operation of detecting the magnitude of the load is performed by utilizing the fact that the magnitude of the motor current increases or decreases corresponding to the magnitude of the load applied to the inner blade 12.
[0063]
Therefore, the rotation speed of the motor 17 is changed by applying a voltage that is constantly or close to the motor 17 as shown in FIG. 10A during high-speed rotation, but as shown in FIGS. 10B and 10C. A configuration is adopted in which the average voltage applied to the motor 17 is lowered by sequentially decreasing the ratio of the voltage application time in one cycle to increase or decrease the motor rotation speed.
[0064]
On the other hand, the load applied to the motor 17 is detected by taking out a voltage that increases or decreases in proportion to the motor current through a low resistance 54 in series with the motor 17. Further, the voltage generated at both ends of the low resistance 54 is integrated by the integrating circuit 55 so that the detection voltage Vf as shown in FIGS. 11A and 11B can be input to the microcomputer device 37.
[0065]
Further, the magnitude of the detection voltage Vf is compared with three comparison voltages VH, VM, and VL obtained by dividing the reference voltage VS output from the constant voltage circuit 41 with a resistor, and the magnitude relationship between the two is determined. Thus, the magnitude of the load applied to the motor 17 is determined in three stages.
[0066]
Here, in this embodiment, the time constant in the integrating circuit 55 is set so that the ripple of the voltage applied to the motor 17 can be reduced as shown in FIG. On the other hand, it is set so as to be smoothed to a small state, and at the time of low speed operation with a long rest period, it is set so as to obtain a waveform with a large ripple that repeats charging and discharging as shown in FIG.
[0067]
In addition, two types of comparison voltages formed by dividing the constant voltage circuit 41 are divided into a first comparison voltage generation circuit 56 for medium and high speed and a second comparison voltage generation circuit 57 for low speed, The comparison voltage can be set and judged according to different standards.
[0068]
That is, the motor load detection at medium and high speeds is formed by dividing the constant voltage circuit 41 because the level fluctuation of the detection voltage Vf with the passage of time is small in the same load state. The two kinds of high and low comparison voltages VH and VM are set, and the magnitude of the load is detected based on the vertical relationship between the comparison voltage and the detection voltage Vf. For example, when the detection voltage Vf is higher than VH, it is determined that the load is high, and high speed rotation is performed. When the detection voltage Vf is between VM and VH, it is determined that the load is medium load. Control that shifts to low-speed rotation by judging the load state.
[0069]
On the other hand, when the motor 17 is rotating at a low speed, the detected voltage Vf changes greatly as shown in FIG. 11B even in the same load state. Therefore, the reference voltage VS is divided to set the comparison voltage VL exclusively for the low speed, and while the peak level of the detection voltage Vf is lower than the comparison voltage VL as shown by the one-dot chain line, it is determined that the load is light and the low speed rotation is maintained. However, when the peak position exceeds the comparison voltage VL as indicated by the solid line, it is determined that the load is medium or heavy, and control for shifting from low speed rotation to medium speed rotation is performed.
[0070]
When the remaining capacity is sufficient, the terminal voltage Ve of the secondary battery 36 gradually decreases after starting the driving of the motor 17 to decrease the rotational speed of the motor. However, when the driving is stopped, the voltage value is restored. To do. In this embodiment, therefore, the battery voltage Ve is lowered by increasing the on-time Ta in the first switching circuit 58 step by step after 1 minute, 2 minutes and 3 minutes from the start of driving of the motor 17. The rotational speed is corrected based on.
[0071]
However, when the remaining battery capacity is lower than the set value, the amount of voltage drop when the motor is driven is larger than in the case described above, and the amount of return is smaller. Therefore, in this case, in addition to the dynamic correction due to the increase in the on-time Ta of the first switching circuit 58 described above, by adding a regular correction that decreases the off-period Tb, A decrease in motor rotation speed due to a decrease in the terminal voltage Ve is corrected.
[0072]
Note that, during AC driving using the charging adapter 26, the voltage applied to the motor 36 is higher and more stable than when driven by the secondary battery 36 alone. Therefore, in this case, the off time Tb of the first switching circuit 58 is increased and the correction operation is not performed as compared with the case of battery driving described above.
[0073]
In order to perform the control operation as described above, the motor control unit 40 connects the first switching circuit 58 in series with the motor 17, while the second switching circuit 59 that is turned on in conjunction with the pressing operation of the main switch 19 and By taking out the terminal voltage Ve of the secondary battery 36 via the normally closed switch 64 that is turned off in conjunction with the removal of the outer blade holder 15 and inputting it as the ON signal to the control terminal of the first switching circuit 58, the first switching circuit 58 is turned on so that a battery voltage can be applied to both ends of the motor 17.
[0074]
In this state, the drive signal Sk applied from the microcomputer device 37 to the control terminal of the third switching circuit 60 is inverted from the waveform shown in FIG. 10, so that the drive signal Sk is in the “H” level period. Correspondingly, the third switching circuit 60 is turned on and the on signal applied to the control terminal of the first switching circuit 58 is short-circuited to turn off, corresponding to the length of the on-time Ta of the first switching circuit 58 in one cycle. The motor 17 rotates at the speed.
[0075]
The three-stage change in the motor rotation speed is displayed by changing the lighting positions of the three light emitting elements 20a, 20b, and 20c provided in the first display unit 21. That is, high-speed operation is indicated by lighting the uppermost light emitting element 20a, medium-speed operation is indicated by lighting the light-emitting element 20b at the intermediate position, and low-speed operation is further indicated by lighting the lowermost light-emitting element 20c. The The change between the manual mode and the automatic mode is displayed separately by setting in advance that the automatic mode is displayed when the second display unit 22 is lit and the manual mode is displayed when the second display unit 22 is turned off.
[0076]
As described above, the second display unit 22 that is turned on in the automatic mode is provided below the light-emitting element 20c for low-speed display in the first display unit 21 that displays the rotation speed of the motor 17 in a stepwise manner. By providing the switching sub switches 23 and arranging them in a line in the vertical direction, the mode switching operation can be performed accurately and the operation and control states can be clearly displayed.
[0077]
Note that the rotation speed display on the first display unit 21 increases or decreases the number of lights corresponding to the increase in speed instead of lighting only the light emitting element 20 corresponding to the current rotation speed as described above. Alternatively, the afterlighting effect can be provided by continuously lighting or blinking the previous lighting position for a set time.
[0078]
By performing such afterimage display, the rotational speed before a predetermined time can be confirmed, and the change in speed can be enjoyed visually. Particularly during shaving, even if there is a rapid change in speed by separating the outer blade 14 from the skin surface, for example, the three light-emitting elements in the first display unit 21 have a rotational speed immediately before shaving. As a result of being displayed as an afterimage using the lighting of 20, it is possible to make an intermediate determination of an unshaven portion.
[0079]
Further, by maintaining the above-mentioned afterimage display for a predetermined time after the motor drive is stopped, it can be estimated from the display content of the first display unit 21 whether or not there is any shaving remaining when the motor drive is stopped. Become. For example, if the high speed state is displayed as an afterimage during shaving, or if the shaving is completed in the high speed state, it is determined that there are many unshaved portions.
[0080]
In the following, based on the mode transition diagram shown in FIG. 12 and the explanatory diagram of the change state of the rotational speed shown in FIGS. 13 to 15, the overall operation procedure of the electric shaver 10 will be centered on the operation procedure in the motor control unit 40. Further details will be described.
[0081]
In the standby mode in which the electric razor 10 is not charged and the motor 17 is stopped, all displays are stopped, the operation of the microcomputer device 37 is set to the power saving state, and the power consumption of the secondary battery 36 is minimized. To the limit.
[0082]
Here, when the main switch 19 is pressed for a short time during the standby mode, the DC mode driven only by the secondary battery 36 is entered, the energization of the motor 17 is started and the motor 17 is rotationally driven. Display on the first to fourth display units 21, 22, 24, and 25 corresponding to the driving state is performed.
[0083]
When the main switch 19 is pushed once again for a short time while the motor 17 is being driven, the energization to the motor 17 is immediately stopped. However, as shown in FIG. 8D, the display on the display unit is temporarily stopped for a short time such as about 0.2 seconds and then stopped again for a short time such as about 3 seconds. After displaying that the driving of the motor 17 has been completed and the detection operation has been performed reliably, a display corresponding to the detection content is displayed to make the operator surely recognize the current operation state.
[0084]
When the charging adapter 26 is connected during the above-described DC mode, the battery enters the AC mode accompanied by the power supply by the charging adapter 26 in addition to the secondary battery 36, and returns to the DC mode when the charging adapter 26 is removed.
[0085]
When the charging adapter 26 is connected during the standby mode, the charging mode is entered. In this mode, capacity detection during charging is performed, and charging timing is displayed on the third display unit 24 corresponding to charging. When it is detected that the charging is completed, the charging is automatically turned off, and the third display unit 24 stops displaying the charging and displays that the charging is completed. Even in this charging mode, if the main switch 19 is pushed and operated, the mode is changed to the AC mode, and if the main switch 19 is pushed again, the charging mode is restored.
[0086]
Further, when the main switch 19 is pushed in the standby mode, the DC mode is entered and the motor 17 is turned on as described above. However, if the main switch 19 is continuously pushed for about 10 seconds, for example, the demonstration is continued. Enter the mode. In this demonstration mode, the driving of the motor 17 is stopped, and a demonstration display for displaying a difference in display contents on the fourth display unit 25 is performed, for example.
[0087]
The display contents and display method in the display unit described above are merely examples, and different display operations are performed according to various detection contents, such as a display corresponding to the degree of accumulation of fuzz and the memory effect of the secondary battery 36. Can do. Further, the display method can be changed, for example, by changing the light emission intensity or light emission color of the light emitting element instead of blinking the light emitting element. Further, by using a buzzer or other sound generation means and performing sound display in addition to the visual display described above, the difference in use mode can be recognized more accurately.
[0088]
Here, when the sub switch 23 is turned on during the execution of the DC mode or the AC mode, the motor 17 sequentially repeats the automatic mode, the high speed rotation drive, the medium speed rotation drive, and the low speed rotation drive every time the switch operation is performed. Immediately before switching from the automatic mode to the manual mode, the low-speed driving state by no-load operation is common, so by entering the high-speed driving state, the switching state is clearly recognized by the user by the change in motor sound. Can be made.
[0089]
Further, when the main switch 19 is turned off in the predetermined selection state by the sub switch 23 to return to the standby mode, the driving state before turning off is stored, and when turning on again, the driving mode before turning off is restored and the operation is resumed. With such a configuration, it is possible to select the desired number of rotations and use the same number of rotations at the next time, which improves usability. In addition, by allowing mode switching by the sub switch 19 only during motor driving, it is possible to prevent an unexpected rotation speed or driving mode from being started at the next use.
[0090]
By the way, when the drive mode when the main switch 19 is turned on is the manual mode, even when the stored speed is at a medium speed or a low speed, as shown at times t1 to t2 in FIG. For example, until the motor rotation for about 1 second is stabilized, a drive signal at high speed is applied to forcibly rotate at high speed, thereby preventing torque shortage at the initial stage of driving.
[0091]
Similarly, even when the mode at the start of driving is the automatic mode, as illustrated at times t1 to t2 in FIG. 13 and FIG. The state is forcibly maintained for about a second. After that, by automatically shifting to the medium speed state, load detection is performed for the first time at that stage, so that the motor drive and load detection can be started in a stable state, and the above control process is always taken. A display function indicating that the control operation is normally performed is exhibited.
[0092]
In addition, as described above, the detection operation is started by forcibly shifting to the medium speed driving state, and the auditory sense due to the change in sound in the drive system including the motor 17 and the visual perception due to the change in the light emission content in the display unit. And can be confirmed.
[0093]
Instead of performing the detection operation in the medium speed drive state, the detection operation may be started in the high speed drive state or in the low speed drive state. For example, it does not drop to medium speed even after a predetermined period of time while maintaining a high speed state, but only after the pressing operation of the skin surface against the outer blade is detected by some method including a pressure sensor and an optical sensor provided for the outer blade. By making it possible to shift to medium speed or low speed through rotation control by subsequent current detection, it is possible to always maintain a high speed state until it touches the skin, eliminating problems such as motor stop due to insufficient initial torque. Can do.
[0094]
On the other hand, when entering the medium speed position and starting the detection operation, the transition time to both speeds is short when the shift to the high speed or low speed state is made by the rotation control accompanying the detection operation, and the speed transition can be performed smoothly.
[0095]
Next, if a heavy load is detected during low-speed driving, or if a light load is detected during high-speed driving, the medium-speed rotation is maintained for a predetermined time instead of immediately shifting to high-speed or low-speed rotation. After that, by shifting to the target rotational speed, a rapid change in speed is avoided, and the operator is prevented from feeling uneasy.
[0096]
However, when a heavy load is detected during low-speed rotation (see time t5 in FIG. 13), the low-speed rotation immediately shifts to the medium-speed rotation, and the medium-speed rotation state is set to a short time of about 1 second. Shift from low speed rotation to high speed rotation as quickly as possible.
[0097]
On the contrary, even if a medium or light load is detected during high-speed rotation (see time t6 in FIG. 13 and time t11 in FIG. 14), it does not immediately shift to medium speed, but after the heavy load state is no longer detected. For example, after the duration of about 4 seconds has elapsed, after confirming that the light load has been maintained, the speed shifts to a medium speed, and the medium speed is also sufficiently longer than the above-described medium speed during the transition from the low speed to the high speed. The time is set to about.
[0098]
With such a configuration, the detection period of heavy load during low-speed driving is generally the case where shaving is started from the no-load state, so at the same time giving a comfortable feeling to the operator by quick response, The presence of a medium speed for a short period of time reduces the burden on the skin caused by a rapid speed change.
[0099]
On the other hand, in the light load detection period at high speed or medium speed rotation, it is common that the load fluctuation is severe by repeating the operation of separating the outer blade 14 from the heel during shaving. By avoiding frequent speed changes, uncomfortable feelings due to unstable speeds are prevented, and a margin period is provided until the next operation is started.
[0100]
Further, since the medium speed or the high speed is maintained for at least a predetermined time (in this embodiment, 4 seconds), the rotational speed of the inner blade 12 immediately before the outer blade 14 is separated from the skin. That is, as a result of maintaining the display corresponding to the magnitude of the load as it is, it is possible to make an intermediate determination of the unshaven portion.
[0101]
Also, immediately after the transition from the medium speed to the low speed (see times t3 to t4 in FIG. 13), the detection voltage is not stable and erroneous detection is likely to occur. For example, the detection operation is not performed during a period of about 1 second. Is set. As a result, it can be reached in a short time, for example about 2 seconds, from low speed rotation to high speed rotation, whereas it takes a minimum of about 8 seconds from high speed rotation to low speed rotation. Need.
[0102]
Here, driving at medium speed and load detection are started at time t2 in FIG. 13. If a heavy load state is detected at that time, the operation immediately shifts to high speed operation without providing a waiting time. On the other hand, if a medium load is detected during driving at medium speed (see time t2 in FIG. 14), driving at medium speed is continued as it is, but even if a light load is detected at time t3 in FIG. No transition is made, and after maintaining the medium speed state for 4 seconds and confirming that the light load state is maintained, the transition is made to the low speed state.
[0103]
As described above, instead of maintaining the high speed or medium speed state for another 4 seconds after the lighter load state is detected, the speed is forcibly set by the timer for 4 seconds after becoming the high speed or medium speed. The state may be maintained, but if the load corresponding to the current speed is not detected immediately after that, the speed may be changed immediately. In addition, as long as the speed increase side can be controlled quickly and the speed decrease side can be controlled slowly, the maintenance time and speed change timing in each speed state can be changed as appropriate.
[0104]
Further, in the case of switching to the automatic mode during the operation in the manual mode (see times t3 and t9 in FIG. 15), when one second has elapsed after the rotation speed is shifted to the medium speed (time in FIG. 15). By starting the load detection from t4 and t10), it is possible to smoothly change the rotation speed and stably detect the load while displaying that the drive mode has been changed from manual to automatic.
[0105]
In addition, as described above, instead of starting the detection operation after maintaining the high speed operation for a predetermined time of about 3 seconds immediately after starting the driving of the motor 17 in the automatic mode and setting the medium speed, the rotation of the motor 17 is performed, for example. At the time of stable high-speed rotation after 1 second, load detection by the motor current described above or load detection by other means is started, and only in that case, it is immediately shifted to medium or low speed without providing a duration of 4 seconds. You may do it.
[0106]
In this case, the sound is displayed by sounding means such as “beep” and buzzer sound several times, or the light emitting element blinks to emit light, thereby starting load detection one second after the start of the high-speed driving described above. Can be displayed, and the user can be surely recognized the start of detection.
[0107]
Also, by providing a switch for determining the automatic mode, it is possible to fix and set the driving speed that the user feels comfortable during execution of the automatic mode. In addition, by providing a learning function of the operation content and starting from the drive content estimated to be optimal at the next drive, the operation is automatically started in the optimal mode, so that the usability is improved. In this case, the content of the learning is estimated from the average load situation at the end of the previous operation and the time elapsed from that time, or the tendency of the operator to use and the speed selection tendency are determined. The contents are not limited.
[0108]
Furthermore, in the above-described embodiment, the average value of the motor current is determined to determine the magnitude of the load. However, the present invention is not limited to this, and instead of or in addition to this detection method, the outer blade 14 or the vicinity thereof is used. It is also possible to provide a sensor that can determine the contact between the skin surface and the outer blade 14, such as a pressure sensor or an optical sensor. In this case, when the pressing pressure is directly detected or the darkness when the outer blade is pressed against the skin is detected, the predetermined rotation speed control is performed by switching to the load detection based on the load current thereafter. be able to.
[0109]
In addition to the above-described determination method based on the load, a method for determining the load state by counting the number of pulse-like fluctuations of the motor current generated during shaving is provided. It is possible to grasp more precisely whether it is being strongly pressed against
[0110]
Furthermore, in place of changing the drive mode of the motor 17 to the circulation type accompanying the pressing operation of the sub switch 23, a slide type or a plurality of push button switches capable of directly selecting each mode are provided. The method of selection can be changed as appropriate.
[0111]
Further, instead of changing the rotational speed of the motor 17 to three steps, it can be changed in four steps or more or in a stepless manner. Even in such a case, it is needless to say that the control state such as the increase or decrease in the motor rotation speed is applied in substantially the same manner. Furthermore, the display on the first display unit 21 is similarly changed in accordance with the number of speed change stages that can be changed.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram schematically showing a basic configuration of the present invention.
FIG. 2 is a partially cutaway front view showing an example in which the present invention is applied to an electric razor.
FIG. 3 is an explanatory diagram showing a configuration of a fourth display unit.
FIG. 4 is a block diagram schematically showing an overall configuration of an electronic circuit.
FIG. 5 is an electric circuit diagram showing a configuration of a charge control unit.
FIG. 6 is a graph showing a change state of a terminal voltage of the secondary battery during charging and discharging.
FIG. 7 is an electric circuit diagram showing a configuration of a battery remaining amount detection unit.
FIG. 8 is an explanatory diagram showing display timing in a fourth display unit.
FIG. 9 is an electric circuit diagram showing a configuration of a motor control unit.
FIG. 10 is a waveform diagram showing an example of a drive voltage applied to a motor.
FIG. 11 is a graph showing a relationship between a detection voltage and a comparison voltage in a motor control unit.
FIG. 12 is a transition diagram showing an operation mode of an electric razor.
FIG. 13 is an explanatory diagram showing a procedure for changing the rotational speed of the motor, and shows a case where the load application period is short.
FIG. 14 is an explanatory diagram showing a procedure for changing the rotational speed of a motor, and shows a case where a load application period is long.
FIG. 15 is an explanatory diagram showing a procedure for changing the rotation speed of the motor, and shows a case where switching between manual and automatic is used.
[Explanation of symbols]
10 Electric razor
11 Body case
12 Inner blade
14 Outer blade
17 Motor
18 Operation panel
19 Main switch
20 Light emitting device
21 1st display part
22 Second display section
23 Sub switch
24 3rd display part
25 Fourth display section
26 Charge adapter
31 Electronic circuit
32 Light emitting device
34 Light guide plate
35 Light diffusion plate
36 Secondary battery
37 Microcomputer device
38 Charge control unit
39 Battery level detector
40 Motor controller
41 Constant voltage circuit
42 First transistor
43 Thermal fuse
44 Second transistor
45 Light emitting device
46 3rd transistor
47 Battery voltage detector
48 Thermistor
49 Battery temperature detection circuit
50 Comparison voltage generation circuit
51 Battery voltage input circuit
52 Booster circuit
53 Switching circuit
54 Low resistance
55 Integration circuit
56 First comparison voltage generation circuit
57 Second comparison voltage generation circuit
58 First switching circuit
59 Second switching circuit
60 Third switching circuit
71 DC power supply
72 Driving means
73 Load current detection means
74 Comparison means
75 Control means
76 resistance
77 Integration means
78 Switching means
79 Operating means
80 Control state display means
81 Control content display means

Claims (4)

In conjunction with the application of the DC voltage, and a driving means for driving the inner cutter at a speed corresponding to the change of the duty ratio in applied voltage (72),
Load current detection means (73) capable of outputting a detection signal whose magnitude changes corresponding to the magnitude of the load current flowing through the drive means (72);
Comparing means (74) for comparing the magnitude of the detection signal output from the load current detecting means (73) with the magnitude of a preset comparison signal and enabling a determination operation corresponding to the magnitude relationship between the two. ,
In response to the determination operation of the comparison means (74), an electric razor comprising control means (75) capable of changing the duty ratio of the voltage applied to the drive means (72),
The magnitude of the detection signal output from the load current detection means (73) includes a first range having a large variation corresponding to a period in which the duty ratio of the voltage applied to the drive means (72) is small, and a duty A second range having a small variation corresponding to a period in which the ratio is large,
The comparison means (74)
In the first range, the peak value of the detection signal can be compared with the magnitude of the comparison signal, while in the second range, the average value of the detection signal can be compared with the magnitude of the comparison signal, An electric shaver characterized in that the two kinds of comparison operations are switched and used in response to a change in duty ratio in the applied voltage . The drive means (72) is a DC motor,
The load current detecting means (73) includes a resistor (76) interposed in series with the driving means (72), and an integrating means (77) for integrating a voltage taken out from both ends of the resistor (76). Consisting of
The electric shaver according to claim 1 , wherein the first range and the second range in the detection signal are set by a time constant in the integrating means (77) . The comparison signal has two sets corresponding to the first range and the second range, and the comparison signal for the first range is one comparison for distinguishing between a low load and a higher load state. The comparison signal for the second range is composed of two comparison voltages for distinguishing between a low load and a medium load and between a medium load and a high load ,
The electric shaver according to claim 2, wherein the comparison means (74) switches and uses the comparison signal corresponding to the first and second ranges in the detection signal . The control means (75) turns on and off the switching means (78) by applying a driving signal whose duty ratio changes in a plurality of stages to the switching means (78) connected in series with the driving means (72). And the operation speed of the drive means (72) can be changed in a plurality of stages, and the duty ratio of the drive signal can be automatically changed in accordance with the contents of the determination operation in the comparison means (74). To do,
When the comparison means (74) determines a load state exceeding the low load state during low speed operation by the drive means (72), the control means (75) performs control to increase the speed of the drive means (72). The electric razor according to claim 3.

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