JPH0377521A - Controller for vacuum cleaner - Google Patents

Abstract

PURPOSE:To improve the precision of dust detection by discriminating the pulse signal outputted from a sensor for detecting the dust in a dust pathway and by counting only the pulse signals over a specified pulse width. CONSTITUTION:After the signal outputted from a photodetector 10 in a dust sensor 12 is amplified in an amplifier part 13 and its waveform is shaped in a pulse transformer part 14, only the pulse signals over a specified pulse width discriminated in a signal-discriminating circuit 17 are counted in a signal- processing part 15 at an interval of a unit time. The power for an electric fan 7 is also controlled by this counted value through a phase control circuit 16. That is to say, in the dust sensor 12, when the position between a light- emitting element 9 and a photodetector 10 is varied by impact, vibration or the like, the narrow width pulse signals generated by the deviation of an optical axis are cut in the signal-discriminating circuit 17, and only the pulse signals over the specified pulse width are detected and counted. In this way, the control with high reliability is made possible against the impact or the vibration.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to improvements in vacuum cleaners used in general households.

BACKGROUND OF THE INVENTION Figures 2 to 4 show a schematic diagram of a conventional vacuum cleaner. In the figure, a hose 3. Extension pipe 4 and suction tool 6 are connected. A hand switch 6 is provided at the tip of the hose 3, and the power of an electric blower 7 disposed inside the cleaner body 1 is controlled by operating the hand switch 6. In addition, the hand operation unit has a light emitting element 9 and a light receiving element 10 in the dust passage 8, which is a part of the hose 3.
are installed facing each other, and changes in the amount of light are detected as the dust 11 passes through the dust passage 8. That is, the light emitting element 9 and the light receiving element 10 form a dust sensor 12.

FIG. 2 is a circuit block diagram of the prior art. In the figure, the light receiving section of the dust sensor 12 (output of the light receiving element 1o)
The signal is amplified by the amplifier 13, waveform-shaped by the pulse converter 14, and input to the signal processor 16. The signal processing section 16 is configured to count the pulse signal from the pulse conversion section 14 every unit time, and based on the counted value, control the electric power of the electric blower 7 via the phase control circuit 16 according to the amount of dust. was.

Problems to be Solved by the Invention However, according to the above-mentioned conventional configuration, since the method detects the change in the amount of light due to the passage of dust between the light emitting element 9 and the light receiving element 10 that constitute the dust sensor 12, the dust sensor 12 is subjected to shocks and vibrations. etc., the optical axis of the dust sensor 12 will shift.
There was a problem in that a pulse signal as shown in a in FIG.

In order to solve the above-mentioned conventional problems, the present invention improves the dust detection accuracy of a dust sensor and provides a product that reliably reacts to even minute dust.

Means for Solving the Problems In order to solve the above-mentioned conventional problems, the present invention uses a signal discrimination circuit to discriminate the pulse signal below the predetermined pulse width plate of the pulse signal from the pulse conversion means, and The configuration is such that only the above pulse signals are counted by the counting means.

Effect: With the means of the present invention, the narrow-width noise generated when shock or vibration is applied to the dust sensor can be eliminated by the gold signal discrimination circuit, and the dust sensor can eliminate the noise generated when dust passes. It works so that only the sys signal is detected.

Example An embodiment thereof will be described below with reference to FIG.

In FIG. 1, parts that are the same as those in FIGS. 2 and 3 are denoted by the same reference numerals, and detailed explanations are omitted. In the figure, the output signal of the light-receiving element 10 of the dust sensor 12 is amplified by the amplifying section 13, waveform-shaped by the pulse converting section 14, and then passed to the signal discrimination circuit 17, where only pulse signals having a predetermined pulse width or more are signaled. The processing unit 15 counts each unit time. Further, the power of the electric blower 7 is controlled via the phase control circuit 16 based on the count value counted by the signal processing section 16.

According to the above configuration, the dust sensor 12 causes the light emitting element 9. A narrow pulse signal (FIG. 5 (IL)-1L) generated due to a shift in the optical axis due to a change in the position of the light-receiving element 1o, that is, a slight change in the amount of light, is cut by the signal discrimination circuit 17, and a predetermined signal is detected. (By detecting and counting only pulse signals that are longer than the pulse width! 1. Highly reliable control of shocks and vibrations is possible. FIG. 6('b) shows the pulse signal (FIG. 5(a)) after passing through the sound signal discrimination circuit 17.

Effects of the Invention As described above, according to the present invention, the reliability of the dust sensor against shocks and vibrations is high, and even if a shock or the like occurs during use, the dust amount can be accurately detected.

In addition, the dust sensor mounting structure conventionally needed to be firmly fixed to prevent malfunction due to vibrations and shocks, but by adopting the method of the present invention, the installation is easier due to the improved impact resistance. It has the advantage of being

[Brief explanation of drawings]

FIG. 1 is a control block diagram showing an embodiment of the present invention, FIG. 2 is a conventional control block diagram, FIG. 3 is an explanatory diagram of the hand-operated part at the end of the hose, and FIG. 4 is a schematic configuration diagram of the vacuum cleaner. FIG. 5 is a pulse signal waveform diagram from the dust sensor. A...Electric blower, 12...Sensor, 14...Pulse converter, 17...Discrimination circuit.

Claims (1)

[Claims] The counting means has a sensor for detecting dust passing through the dust passage, a pulse converting means for converting the output of the sensor into a pulse signal, and a counting means for counting the number of pulses from the pulse converting means within a unit time, and the counting means A control device for controlling electric power of an electric blower based on a count value counted in a vacuum cleaner, comprising a discrimination circuit that does not detect a pulse signal having a predetermined pulse width or less of a pulse signal from the pulse conversion means as a pulse signal. Device.