JPH03237998A - Controller for washing machine - Google Patents

Abstract

PURPOSE:To detect accurately the dirtiness of washing water to be used in the next washing by storing the luminescent output data of a photosensor for detecting the light transmittivity of liquid in a tank, comparing the stored luminescent output data with luminescent output data and storing the previous luminescent output data when a difference exceeding a predetermined value is found. CONSTITUTION:When water is supplied up to a predetermined level in a washing tank, a microcomputer 4 outputs a PWM signal to control current If of a luminescent element 1a in a photosensor 1 for turning on a transistor 2d. The output voltage VC of the photosensor 1 is A/D converted to be inputted to the microcomputer 4 and judged whether or not it is predetermined set value V0. If it is the set value, the If data by the previous PWM control are inputted to the microcomputer 4. A difference between the previous If data and the present set If data is calculated by a comparing means 5. Whether or not thus calculated difference falls within a predetermined value is judged. If the difference does not fall within the predetermined value, dirty water such as remaining hot water in a bathtub is judged to be supplied so that the control according to the dirtiness of the water is determined to be carried out. Then, the previous luminescent output data is memorized again in a memory means 3.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a control device for a washing machine equipped with an optical sensor that detects the light transmittance of washing liquid and rinsing liquid in a washing tub.

Prior art A conventional control device for this type of washing machine was disclosed in Japanese Patent Application Laid-Open No. 61-505.
There is something shown in Publication No. 95. In other words, it optically detects the turbidity of water in the washing tub.The degree of dirt is detected by changes in the output signal of the light-receiving element of the optical sensor, which is made up of a light-emitting element and a light-receiving element, and controls when washing ends. It was something to do.

However, with this configuration, the change in turbidity of the washing liquid is greatly affected by the type and amount of detergent, and in particular, the change in turbidity of liquid detergent is very small compared to that of powder detergent. Therefore, in order to determine the type and amount of this detergent, the light emitting output of the light emitting element of the optical sensor is controlled to a predetermined reference value when fresh water is supplied, and this light emitting output data is stored in a storage means. , the end time of the washing time was controlled as reference data for the next washing.

Problems to be Solved by the Invention However, a problem with this method is that the water supply liquid at the time of water supply is not necessarily clean tap water. In other words, the most commonly used water for washing is the leftover hot water from the bath. The remaining water from a bath is generally cloudy compared to tap water, and more recently bath salts are being used in many cases. Therefore, if the light emitting output of the optical sensor is adjusted to a predetermined reference value with cloudy water such as leftover hot water in a bath, it will not be possible to accurately detect the turbidity of the washing liquid during the next wash. There has been a problem in that the end of the washing time does not match the amount of dirt on the laundry, and the dirt is not removed sufficiently.

Therefore, an object of the present invention is to allow the next washing to be completed in a washing time corresponding to the dirtiness of the laundry even if the light emission output of the optical sensor is adjusted in the case of cloudy water such as bath water.

Means for Solving the Problems In order to achieve this object, the present invention provides an optical sensor comprising a light emitting element and a light receiving element for detecting the light transmittance of the washing liquid and rinsing liquid in the washing tub, and the light emitting element of the optical sensor. a light emission output control means for controlling the light emission output of the element to a predetermined reference value when water is supplied; a memory means for storing light emission output data by the light emission output control means; and a light emission output stored in the memory means. and a comparison means for comparing the data and the light emission output data, and when the light emission output data differs from the previously stored light emission output data by a predetermined value or more, the previous light emission output data is stored in the memory. The information is stored in a means.

With this configuration, even if the laundry is done with cloudy water such as leftover water from a bath, the washing time can be controlled according to the water, and the light output data of the previous light sensor is stored and used for the next wash. Since this data is used, it is possible to accurately detect the turbidity of the washing water during the next wash.

Embodiment Hereinafter, one embodiment of the present invention will be described based on the accompanying drawings. FIG. 1 shows a washing machine control device according to the present invention. In the figure, 1 is an optical sensor consisting of a light emitting element 1a and a light receiving element 1b for detecting the light transmittance of the washing liquid and rinsing liquid in the washing tub, and 2 is the light emitting output of the light emitting element 1a of the optical sensor 1. A light emission output control means controls the light emission output to a predetermined reference value at the time of water supply. Reference numeral 3 denotes a storage means for storing light emission output data from the light emission output control means 2, and uses, for example, a non-volatile memory. 4 is a microcomputer 4, which includes a pulse width control circuit (hereinafter referred to as PWM circuit) for controlling the current If of the light emitting element 1a of the optical sensor 1, and an A/D conversion circuit for converting an analog signal into a digital signal. ing. D the PWM signal from the microcomputer 4
In addition to the /A conversion circuit 2a (usually an integrating circuit), the voltage is converted to a DC voltage and the base voltage of the transistor 2b is controlled.

The light emitting element 1a of the optical sensor 1 is connected to the collector of the transistor 2b, and the emitter resistor 2c is connected to the emitter of the transistor 2b, so that it becomes a constant current circuit, and the current of the light emitting element 1a can be controlled by the base voltage. Emitter resistance 2
A transistor 2b is connected in series with C, and the SW signal of the microcomputer 4 controls the on/off of the current in the light emitting element 1a to drive the light emitting element 1a in pulses. A voltage corresponding to the turbidity of the washing liquid is inputted to the A/D input of the microcomputer 4 from the load resistor 2e of the phototransistor 1b of the optical sensor 1.

FIG. 2 shows changes in the output of the optical sensor 1 during the entire stroke of the fully automatic washing machine. In this case, in the previous washing, the current of the light emitting element was controlled so that the light emission output of the optical sensor 1 became a predetermined reference voltage Vo. As is clear from Fig. 2, using the output voltage Vo of the optical sensor 1 during water supply for rinsing as a reference, the light transmittance during washing, that is, the turbidity of the washing liquid, can be determined by changes from there, and the degree of dirt and the turbidity of the washing liquid can be determined. I can see the fall. You can also see the change from clean water during rinsing. Based on this turbidity, the dirtiness of the laundry is estimated and the end time of the washing period is controlled.

FIG. 3 is a flowchart for setting the light emission output Vc of the light emitting element of the optical sensor according to this embodiment to a predetermined reference voltage Vo by supplying water for rinsing. In step 10, water supply into the washing tub is started. When water is supplied to the washing tub to a predetermined water level, the microcomputer 4 goes to step 11 to check the current of the light emitting element 1a of the optical sensor 1! , PWM to control
A signal is output and transistor 2d is turned on. and,
The output voltage Vc of the optical sensor 1 is input to the microcomputer 4.
Then, in step 12, it is determined whether the current VC is a predetermined set value vo. If the set value is not reached, the process returns to step 11 and PWM control is performed again. If it is the set value, in step 13 the previous PWM
If data under control is input to the microcomputer 4. vinegar.

In step 14, the comparing means 5 calculates the difference between the previous rr data and the currently set If data.

In step 15, it is determined whether the difference between the results of this comparison calculation is within a predetermined value. If it is within the predetermined value, the current light emission output data of the optical sensor is stored in the storage means 3 in step 6. If it is not within the specified value,
It is determined that turbid water such as leftover bath water is supplied, and the washing time control and rinsing control are determined in accordance with the turbidity of the water. Then, the previous light emission output data is stored in the storage means 3 again in step 17. Then, the process proceeds to the next process of step 18.

Effects of the Invention As is clear from the above embodiments, the washing machine control device of the present invention includes a light sensor comprising a light-emitting element and a light-receiving element that detect the light transmittance of the washing liquid and rinsing liquid in the washing tub; a light emission output control means for controlling the light emission output of the light emitting element of the optical sensor so that it reaches a predetermined reference value when water is supplied; a storage means for storing light emission output data by the light emission output control means; Since it has a comparison means for comparing the luminescence output data and the luminescence output data, it is possible to determine whether the water used for washing is clean water or cloudy water such as leftover water from a bath. Can be judged. Washing can then be controlled in accordance with the turbidity of the water.

Furthermore, when the light emission output data differs from the previously stored light emission output data by a predetermined value or more, the previous light emission output data is stored in the storage means, so that the remaining light output data in the bathtub is stored. Even when washing with cloudy water such as hot water, the light output data of the optical sensor from the previous time when the water was fresh is retained and used as data for the next wash, making it possible to accurately detect the turbidity of the wash water during the next wash. Become.

[BRIEF DESCRIPTION OF THE DRAWINGS] Fig. 1 is a block diagram showing a control device for a washing machine according to an embodiment of the present invention, Fig. 2 is a characteristic diagram showing the output of the same optical sensor, and Fig. 3 is a characteristic diagram showing the output of the same optical sensor. 3 is a flowchart showing a method for setting a reference value. l... Optical sensor-1a... Light emitting element,
1b...Light receiving element, 2...Light emission output control means, 3...Storage means, 5...Comparison means.

Claims (2)

[Claims] (1) A light sensor consisting of a light emitting element and a light receiving element detects the light transmittance of the washing liquid and rinsing liquid in the washing tub, and the light output of the light emitting element of the light sensor is set to a predetermined reference value when water is supplied. a light emission output control means for controlling the light emission output, a storage means for storing light emission output data by the light emission output control means, and a comparison means for comparing the light emission output data stored in the storage means and the light emission output data. washing machine control device. (2) The washing machine according to claim 1, wherein when the light emission output data differs from the previously stored light emission output data by a predetermined value or more, the previous light emission output data is stored in the storage means. Control device.