JP2956235B2 - Vacuum cleaner dust detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dust detector for a vacuum cleaner for detecting dust passing through an air passage of the vacuum cleaner.

[0002]

2. Description of the Related Art Heretofore, a dust detector for a vacuum cleaner of this type has generally been configured as shown in FIGS. Hereinafter, the configuration will be described.

As shown in the figure, a light emitting diode 4 is provided in a suction passage 3 extending from a floor suction port 1 of a vacuum cleaner to a suction port 2 of a vacuum cleaner main body. And the light from the light emitting diode 4 was received. If dust is contained in the suction airflow flowing through the suction passage 3 during the cleaning operation, the light from the light emitting diode 4 is blocked by the dust, and the phototransistor 5 receives less light and outputs light. The voltage increases. As a result, the output voltage of the voltage change amplifier 10 composed of the resistors 6 and 7, the capacitor 8 and the OP amplifier 9 once decreases and then increases. Therefore, although the output voltage of the comparison unit 14 composed of the resistors 11 and 12 and the OP amplifier 13 is 5 V in a normal state, the output voltage is once reduced to 0 V and then returned to 5 V each time dust passes. Repeat the operation. The output of the comparison unit 14 is input to the microprocessor 15 and drives the fan motor 16 and the display unit 17. The basic time for detecting dust in the microprocessor 15 is 0.1 second. That is, the microprocessor 15 determines the amount of dust based on the number of changes in 0.1 second.

The light emitting diode 4 and the phototransistor 5 are generally inserted and installed in transparent holders 18 and 19 in order to prevent contamination from dust.
Further, in order to correct variations in the sensor section including the light emitting diode 4, the phototransistor 5, and the holders 18 and 19 in which the light emitting diode 4 and the phototransistor 5 are provided, the variable resistor 20 is used so that the light emitting current can be adjusted. Is adjusted to be 3V.

[0005]

However, in such a conventional dust detector for a vacuum cleaner, the amount of dust adhering to the surfaces of the holders 18 and 19 increases as the cleaning time increases. Light gradually stops reaching the phototransistor 5, and the voltage of the phototransistor 5 rises to 4V or more even if the voltage is initially 3V,
The dust detection sensitivity has been reduced, and the user has to clean the holders 18 and 19 for dirt.

The present invention has been made to solve the above-mentioned problem, and when there is a change in the output of a light receiving unit, it is determined whether or not the change is due to dirt. The purpose of the present invention is to always maintain a constant voltage, prevent dust from being undetectable, and improve usability and durability.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a light emitting unit which emits light in an air passage through which dust flows, and which receives light from the light emitting unit and outputs a signal corresponding to the amount of received light. A voltage setting unit that sets a detection level of the light receiving unit, a change detection unit that detects a change in an output voltage of the light receiving unit based on outputs of the light receiving unit and the voltage setting unit, and the change detection unit. A time measuring unit that measures a time during which a change is detected, a preset time setting unit, and whether or not a change in the output voltage of the light receiving unit is caused by dirt is determined by the outputs of the time measuring unit and the time setting unit. A dirt determining unit for determining,
A light-emitting current setting unit configured to set a plurality of energizing currents to the light-emitting unit; and a light-emitting current selection unit that selects a current of the light-emitting current setting unit. The first problem solving means is to select the current of the light emission current setting section.

A light emitting unit that emits light into an air passage through which dust flows, a light receiving unit that receives light from the light emitting unit and outputs a signal corresponding to an amount of received light, and a detection level of an upper limit of the light receiving unit. An upper limit voltage setting section to set, a lower limit voltage setting section to set a lower detection level of the light receiving section, and a change in an output voltage of the light receiving section by comparing outputs of the light receiving section and the upper limit voltage setting section or the lower limit voltage setting section. A change detection unit that detects
A time measuring unit that measures the time during which the change detecting unit detects the change, a preset time setting unit, and a change in the output voltage of the light receiving unit due to dirt due to the outputs of the time measuring unit and the time setting unit. A dirt discriminating unit for discriminating whether or not the light is emitted, a light emitting current setting unit for setting a plurality of currents to the light emitting unit, and a light emitting current selecting unit for selecting a current of the light emitting current setting unit. A second means for solving the problem is that the current selection section selects the current of the light emission current setting section based on the output of the dirt determination section.

[0009]

According to the first aspect of the present invention, there is provided:
The output voltage of the light receiving unit is constantly measured, and if there is a change in the output, the dirt discriminating unit determines whether the change is due to dirt. The light emission current can be adjusted by the light emission current selection unit so that the voltage of the light emission unit becomes constant.

According to the second means for solving the problem, the output voltage of the light receiving section is constantly measured, and if there is a change in the output, it is determined by the dirt determining section whether or not the output is caused by dirt. If it is due to dirt, the light-emitting current can be adjusted by the light-emitting current selector so that the output voltage of the light-receiving unit is from the lower limit to the upper limit of the set voltage. Does not become undetectable.

[0011]

An embodiment of the present invention will be described below with reference to FIG. The same components as those in the conventional example are denoted by the same reference numerals, and description thereof is omitted.

As shown in the figure, a light emitting section 21 emits light into an air passage through which dust flows, and uses a light emitting diode 4. The light receiving unit 2 receives the light from the light emitting unit 21 and outputs a signal corresponding to the amount of received light. It consists of: When dust is contained in the suction airflow flowing through the suction passage during the cleaning operation, the light from the light emitting diode 4 is blocked by the dust, the light receiving amount of the phototransistor 5 decreases, and the output voltage of the phototransistor 5 decreases. Becomes larger. As a result, the output voltage of the light receiving section 22 once decreases and then increases. The output of the light receiving section 22 is connected to resistors 23 and 24 and OP
It is input to a comparison unit 26 composed of an amplifier 25. The voltage setting section 27 sets the detection level of the light receiving section 22 and is constituted by resistors 28 and 29 and is set to about 3.1V. The change detecting section 30 detects a change in the output voltage of the light receiving section 22 based on the outputs of the light receiving section 22 and the voltage setting section 27, and uses a comparator 31.

Next, the time measuring section 32 is connected to the change detecting section 30.
Is used to measure the time during which the output voltage of the light receiving section 22 is changing. The time setting unit 33 is a time measuring unit 3
2. The maximum time to be measured is set in advance. The dirt determining unit 34 determines whether the change in the output voltage of the light receiving unit 22 is due to dirt by comparing the time measuring unit 32 and the time setting unit 33. Further, the light-emitting current setting unit 35 is
This is for setting a plurality of conduction currents to one, and is constituted by a plurality of resistor groups. The light emission current selection section 36 selects the current of the light emission current setting section 35 based on the output of the dirt determination section 34, and selects the output voltage of the light receiving section 22 to be about 3V. All these systems are set to operate at 5V.

The time measuring unit 32, the time setting unit 33,
The dirt determination unit 34 and the light emission current selection unit 36 are configured in a microprocessor 37. The output of the comparison unit 26 is input to the microprocessor 37 to drive the fan motor 16 and the display unit 17. The basic time for detecting dust in the microprocessor 37 is 0.1 second. That is, the microprocessor 37 determines the amount of dust based on the number of changes in 0.1 second.

The operation of the above configuration will be described with reference to FIGS. 2 and 3. If dust is not sucked in, the output of the light receiving section 22 is constant at 3 V as in the conventional example, and the change detecting section 30 operates. No light emission current selection unit 3
An arbitrary resistor is selectively output from 6 so that the output voltage of the light receiving section 22 becomes 3 V (FIG. 2A). However, when the dust passes, the output of the light receiving unit 22 repeats the operation of decreasing from the steady 3V to 0V and returning to 3V again, so that the output of the change detecting unit 30 changes from “L” to “H”. , The time measuring unit 32 measures the changing time. When the dust actually passes, the output of the change detection unit 30 repeats the operation of “L” → “H” → “L”, so the time measurement unit 32 repeatedly starts and stops the operation, and outputs a large value. There is no counting. By inputting a large value to the time setting unit 33 in advance and comparing it with the output of the time measuring unit 32, the dirt determining unit 34 does not operate. In the present embodiment, the value of the time setting unit 33 is set to 0.1 second, which is the basic time for the microprocessor 37 to detect dust (FIG. 2B).

On the other hand, as the light emitting unit 21 is used,
Since dust and dirt gradually adhere to the surface of a holder (not shown) to which the light receiving unit 22 is attached,
The output voltage of the light receiving section 22 gradually increases from 3V. Then, the output of the change detecting unit 30 changes from “L” to “H” by comparison with the voltage setting unit 27, and the time measuring unit 32
Starts operation (T1 in FIG. 2 (c)). In this case, since the output voltage of the light receiving unit 22 does not change, the time measuring unit 32 continues its operation, and eventually becomes larger than the value set in the time setting unit 33 in advance. Then, the dirt determination unit 34 operates to drive the emission current selection unit 36, and the emission current setting unit 3
Select any value of 5. As a result, the current flowing through the light emitting unit 21 increases, and the voltage of the light receiving unit 22 decreases.
In this operation, the output of the change detecting unit 30 changes from “H” to “L”, that is, the output of the light receiving unit 22 is changed to the voltage setting unit 2.
7 until it becomes smaller than the set voltage, and stops when the relationship is reversed (T2 in FIG. 2 (c)).

That is, the light receiving section 22 is
By measuring the change time of the light receiving section 22, it can be determined whether or not the voltage change of the light receiving section 22 is due to dust detection. When it is determined that the voltage change is caused by dirt, the light emission current selecting section 36 is driven to output the output of the light receiving section 22. It can be corrected so that the voltage becomes the initial value 3V.

Next, another embodiment of the present invention will be described with reference to FIG. The components having the same configuration as the above embodiment are denoted by the same reference numerals, and description thereof will be omitted.

As shown in the figure, an upper limit voltage setting section 38 and a lower limit voltage setting section 39 are composed of resistors 40, 41 and 42, and compare with the output voltage of the light receiving section 22. The upper limit voltage comparator 43 and the lower limit voltage comparator 44 are composed of comparators 45 and 46, respectively. The change detecting section 47 detects a change in the light receiving section 22 by performing an OR operation on the outputs of the upper limit voltage comparing section 43 and the lower limit voltage comparing section 44.
In this embodiment, the upper limit voltage is set to 3.1 V, and the lower limit voltage is set to 2.9 V. For this reason, the output voltage of the light receiving section 22 is usually 3V. At this time, since both the upper limit voltage comparing section 43 and the lower limit voltage comparing section 44 are “L”, the output of the change detecting section 47 is “L”.

The operation of the above configuration will be described with reference to FIGS. 5 and 6. When dust is not sucked in and when dust passes therethrough, the operation is the same as in the above embodiment (FIG. 5 (a)). , (B)). On the other hand, as the device is used, dust and dirt gradually adhere to the surface of a holder (not shown) to which the light emitting unit 21 and the light receiving unit 22 are attached, so that the output voltage of the light receiving unit 22 gradually increases from 3V. Will rise. When the voltage exceeds 3.1 V, the output of the upper limit voltage comparing section 43 becomes'
L ′ → “H”, the change detecting unit 47 operates, and the time measuring unit 32 starts operating. In this case, since the output voltage of the light receiving unit 22 does not change, the time measuring unit 32 continues its operation, and eventually becomes larger than the value set in the time setting unit 33 in advance. Then, the dirt determination unit 34 operates to drive the emission current selection unit 36 and select an arbitrary value of the emission current setting unit 35. As a result, the voltage of the light receiving section 22 gradually decreases. In this operation, the change detecting unit 43 stops the operation, that is, the output of the light receiving unit 22 is changed to the upper limit voltage setting unit 38.
, And stops when the relationship is reversed (FIG. 5 (c)).

Next, during use, the voltage of the light receiving section 22 may decrease due to the influence of strong external light for an arbitrary time. At this time, when the output of the light receiving unit 22 becomes smaller than 2.9 V, the change detecting unit 43 operates by comparison with the lower limit voltage setting unit 39, and the time measuring unit 32 starts operating. In this case, since the output voltage of the light receiving unit 22 does not change, the time measuring unit 32 continues its operation, and eventually becomes larger than the value set in the time setting unit 33 in advance. Then, the dirt determination unit 34 operates to drive the emission current selection unit 36 and select an arbitrary value of the emission current setting unit 35. Thus, the voltage of the light receiving section 22 gradually increases. This operation continues until the change detection unit 43 stops operating, that is, continues until the output of the light receiving unit 22 becomes higher than the set voltage 2.9 V of the lower limit voltage setting unit 39, and stops when the relationship is reversed ( FIG. 5 (d)).

That is, in the time measuring section 32, the light receiving section 22
By measuring the change time, it is possible to determine whether the voltage change of the light receiving unit 22 is due to dust detection or the influence of external light, and when it is determined that the voltage change is due to dirt or external light,
By driving the light emitting current selection unit 36, the output voltage of the light receiving unit 22 can be corrected so as to have the initial value of 3V.

[0023]

As is apparent from the above embodiments, according to the present invention, a light emitting section for emitting light into an air passage through which dust flows, and a signal corresponding to the amount of received light and receiving the light from the light emitting section are output. A voltage setting unit that sets a detection level of the light receiving unit, a change detection unit that detects a change in an output voltage of the light receiving unit based on outputs of the light receiving unit and the voltage setting unit, and the change detection unit. A time measuring unit that measures a time during which a change is detected, a preset time setting unit, and whether or not a change in the output voltage of the light receiving unit is caused by dirt is determined by the outputs of the time measuring unit and the time setting unit. A dirt determining unit for determining,
A light-emitting current setting unit configured to set a plurality of energizing currents to the light-emitting unit; and a light-emitting current selection unit that selects a current of the light-emitting current setting unit. Since the current of the light emission current setting section is selected, the output voltage of the light receiving section is always measured, and if there is a change in the output, the dirt determination section determines whether or not the change is due to dirt. The light emission current is adjusted by the light emission current selection unit so that the output voltage of the light receiving unit is always kept at a constant voltage if it is determined that the light is from dirt. Does not become undetectable. Also, the user does not need to clean the holder.

An upper limit voltage setting section for setting an upper detection level of the light receiving section; a lower voltage setting section for setting a lower detection level of the light receiving section; A change detection unit that detects a change in the output voltage of the light receiving unit by comparing the outputs of the units, a time measurement unit that measures the time during which the change detection unit detects a change, a preset time setting unit, A dirt determining unit that determines whether a change in the output voltage of the light receiving unit is due to dirt by an output of the time measuring unit and the time setting unit, and a light emitting current setting unit that sets a plurality of currents to the light emitting unit. ,
A light emission current selection unit that selects the current of the light emission current setting unit, and the light emission current selection unit selects the current of the light emission current setting unit based on the output of the dirt discrimination unit. The voltage is constantly measured, and when there is a change in the output, the dirt determination unit determines whether the change is due to dirt or external light. Since the emission current is adjusted by the emission current selection unit so that the output voltage of the unit always becomes a constant voltage, it is possible that the voltage of the light receiving unit increases due to dirt and dust cannot be detected. There is no malfunction due to the influence of strong external light. Also, the user does not need to clean the holder.

[Brief description of the drawings]

FIG. 1 is a block circuit diagram of a dust detection device of a vacuum cleaner according to one embodiment of the present invention.

Fig. 2 (a) The main part output waveform diagram when there is no dirt and the dust does not pass in the air passage of the dust detector of the same vacuum cleaner (b) In the air passage of the dust detector of the same vacuum cleaner Output waveform diagram of main parts when dust passes without dust (c) Output waveform diagram of main parts when dirt is present in the air passage of the dust detector of the vacuum cleaner

FIG. 3 is a flowchart of a dust detection device of the vacuum cleaner.

FIG. 4 is a block circuit diagram of a dust detection device of a vacuum cleaner according to another embodiment of the present invention.

FIG. 5 (a) is a main part output waveform diagram when there is no dirt in the air passage of the dust detection device of the same vacuum cleaner and no dust passes. (B) In the air passage of the dust detection device of the same vacuum cleaner. Output waveform diagram of the main part when dust passes without contamination (c) Output waveform diagram of the main part when there is dirt in the air passage of the dust detector of the vacuum cleaner (d) Principal part output waveform diagram when outside light is affected in the air passage

FIG. 6 is a flowchart of a dust detection device of the vacuum cleaner.

FIG. 7 is a block circuit diagram of a dust detection device of a conventional vacuum cleaner.

FIG. 8 is a sectional view of a main part of the dust detection device of the vacuum cleaner.

[Explanation of symbols]

 21 light emitting part 22 light receiving part 27 voltage setting part 30 change detecting part 32 time measuring part 33 time setting part 34 dirt discriminating part 35 light emitting current setting part 36 light emitting current selecting part

Continuation of front page (58) Field surveyed (Int.Cl. ⁶ , DB name) A47L 9/28

Claims (3)

(57) [Claims] 1. A light emitting unit that emits light into an air passage through which dust flows, a light receiving unit that receives light from the light emitting unit and outputs a signal corresponding to an amount of received light, and a voltage that sets a detection level of the light receiving unit A setting unit, a change detection unit that detects a change in the output voltage of the light receiving unit based on the outputs of the light receiving unit and the voltage setting unit,
A time measuring unit that measures the time during which the change detecting unit detects the change, a preset time setting unit, and a change in the output voltage of the light receiving unit due to dirt due to the outputs of the time measuring unit and the time setting unit. A dirt discriminating unit for discriminating whether or not the light is emitted, a light emitting current setting unit for setting a plurality of currents to the light emitting unit, and a light emitting current selecting unit for selecting a current of the light emitting current setting unit. A dust detection device for a vacuum cleaner, wherein the current selection unit selects the current of the light emission current setting unit based on the output of the contamination determination unit. 2. A light-emitting unit that emits light into an air passage through which dust flows, a light-receiving unit that receives light from the light-emitting unit and outputs a signal corresponding to a light-receiving amount, and a detection level of an upper limit of the light-receiving unit. An upper limit voltage setting section to set, a lower limit voltage setting section to set a lower detection level of the light receiving section, and a change in an output voltage of the light receiving section by comparing outputs of the light receiving section and the upper limit voltage setting section or the lower limit voltage setting section. A time detecting unit that measures a time during which the change detecting unit detects a change, a preset time setting unit, and the light receiving unit based on outputs of the time measuring unit and the time setting unit. A dirt determining unit that determines whether the change in the output voltage is caused by dirt; a light-emitting current setting unit that sets a plurality of currents to the light-emitting unit; and a light-emitting current that selects a current of the light-emitting current setting unit. And a selection unit. A dust detection device for a vacuum cleaner, wherein the photocurrent selection unit selects the current of the emission current setting unit based on the output of the dirt determination unit. 3. The setting time of the time setting unit is a basic time for detecting dust or a time longer than the basic time.
A dust detection device for a vacuum cleaner according to claim 2.