JPH0338875B2 - - Google Patents

Description

TECHNICAL FIELD The present invention relates to a washing machine equipped with an optical turbidity detector.

(Prior Art) Conventionally, a washing machine has been proposed that is equipped with a turbidity detector that optically detects changes in the turbidity of a washing liquid, and that controls washing or rinsing operations based on a signal from the turbidity detector. There is.

However, turbidity detectors have a problem in that the detection level for the same turbidity varies greatly from one turbidity detector to another due to variations in the light-emitting elements and light-receiving elements themselves, variations in manufacturing, and the like. Therefore, when incorporating a turbidity detector into a washing machine, various means are required to match the turbidity detector and the control circuit of the washing machine, which has the disadvantage of making the entire system expensive. Ta.

(Purpose) The present invention has been made in view of the above points, and it is an object of the present invention to correct variations only by adjusting the turbidity detector side, and to eliminate the need for a means for matching with the turbidity detector on the control circuit side. This provides an inexpensive system as a whole.

(Example) Examples of the present invention shown in the drawings will be described in detail below.

First, in FIG. 1, reference numeral 1 indicates a communication pipe which is in communication with the washing tub and through which the cleaning liquid in the washing tub flows when the pulsator rotates, 2 is a transparent detection window provided opposite to the communication pipe 1, and 3 is a light emitting element, 4 is a light receiving element, 5 is a correction resistor connected to the light emitting element 3,
These constitute a turbidity detector.

Therefore, the variation correction of the turbidity detector is performed by the following procedure. First, the turbidity detector is assembled into a completed product, the light emitting element 3 is made to receive light, and the detection window 2 and the inside of the communication tube 1 are This is done by measuring the detection level of the light receiving element 4 that receives the light transmitted through the detection window 2, and adjusting the value of the correction resistor 5 so that the detection level becomes a predetermined value. By performing such variation correction for each turbidity detector, it is possible to obtain the same detection level for the same turbidity, and therefore the washing machine control circuit side can easily adjust the matching with the turbidity detector. There is no need for a means to
An inexpensive system can be provided as a whole.

Next, a description will be given of an adjustment method when the turbidity detector is actually used in a washing machine.

First, FIG. 4 is a diagram showing the relationship between the correction resistor 5 and the detection level of the light receiving element 4. In FIG. The curve shown as shows the characteristics when the inside of the conduction tube 1 is a cleaning liquid. When the correction resistance value approaches 0, the detection level of both the air curve and the cleaning liquid X curve decreases.
Become a Vm. However, the corrected resistance value when the detection level is Vc needs to be reduced to A compared to the corrected resistance value B of air because the cleaning liquid transmits light less easily than air. Figure 5 shows turbidity and light receiving element 4.
is a diagram showing the relationship between the detection level of
In the figure, when the corrected resistance value is A, b indicates the relationship when the corrected resistance value is B in FIG.
Hereinafter, the case of washing operation will be explained as an example.

Now, if the corrected resistance value A is determined with the cleaning liquid at the initial stage of washing inside the communication pipe 1, the relationship between the turbidity and the detection level of the light receiving element 4 will be as shown in Figure 5 by a, As the washing progresses, the turbidity increases from the turbidity Z, and the detection level of the light receiving element decreases linearly accordingly, making it possible to accurately detect changes in turbidity. On the other hand, if the corrected resistance value B is determined in the air condition, the detection level will decrease because the corrected resistance value is large, and the relationship between the turbidity and the detection level of the light receiving element 4 will be as shown by b in FIG. Although the turbidity increases from the turbidity Z as washing progresses, the change in the detection level of the light receiving element 4 is extremely small, making it difficult to accurately detect the change in turbidity.

Therefore, either by putting a cleaning liquid inside the conduit tube 1 or by inserting a filter having the same degree of turbidity,
It is necessary to determine the value of the correction resistor 5 so that the detection level of the light-receiving element 4 is constant, but it is extremely difficult to add cleaning liquid or a filter to each turbidity detector, and it is difficult to install a filter. There were problems such as variations in both directions, making it impractical.

However, in this example, first, in one turbidity detector serving as a reference, the corrected resistance value A in the state containing the cleaning liquid at the initial stage of washing and the corrected resistance value B in the air state are determined. Then, adjust the value of the correction resistor 5 so that the detection level of the light receiving element 4 of the turbidity detector to be adjusted is constant in the air condition, and set the value at this time as B' to detect the turbidity. In the container, B′−
Actually install the correction resistor 5 having the value A' obtained by the equation (B-A). That is, by calculating the values A and B for one turbidity detector in advance, the subsequent turbidity detectors can only be adjusted in the air condition, and the corrected resistance value B' obtained at this time and A corrected resistance value A' of the turbidity detector to be corrected in a cleaned state is calculated from the above corrected resistance values A and B, and the value of the corrected resistance 5 is determined. By doing this, there is no need to add a cleaning solution or a filter to each turbidity detector, making it easy to adjust the turbidity detector, which is useful in practice. 4, the detection level changes are large, and turbidity changes can be detected accurately.

In addition, when adjusting based on the case of rinsing operation, the adjustment is made in the same manner as above by using clean water instead of the washing liquid at the initial stage of washing.

FIG. 2 shows another embodiment of the present invention, in which a correction resistor 6 is connected to the light receiving element 4 to correct variations and adjust the detection level of the light receiving element 4. or,
FIG. 3 shows another embodiment of the present invention, in which a light emitting element 3
Correction resistors 5 and 6 are connected to both the light receiving element 4 and the light receiving element 4.

(Effect) As described above, in the present invention, if the corrected resistance value of the turbidity detector for air is determined, the corrected resistance value for the cleaning liquid is calculated from the corrected resistance value for air and cleaning liquid of the turbidity detector as a reference. To provide an inexpensive system as a whole, which can calculate and correct variations only by adjusting the turbidity detector, and eliminates the need for means for matching with the turbidity detector on the control circuit side. Can be done.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a turbidity detector in one embodiment of the present invention, FIGS. 2 and 3 are block diagrams of a turbidity detector in other different embodiments of the present invention, and FIG. 4 is a correction resistor. FIG. 5 is a diagram showing the relationship between turbidity and the detection level of the light receiving element. 1: Communication tube, 2: Detection window, 3: Light emitting element, 4:
Light receiving element, 5, 6: correction resistor.

Claims (1)

[Claims] 1. A washing machine that includes a turbidity detector that detects changes in the turbidity of a cleaning liquid using a combination of a light-emitting element and a light-receiving element, and that controls operations such as washing based on a signal from the turbidity detector. In the machine, in order to match the output signal characteristics of the turbidity detector described above, using the turbidity detector as a reference, the corrected resistance value A when cleaning liquid is detected in the initial stage of washing and the corrected resistance value B when air is detected are calculated. From the measurement result B′ of the corrected resistance value during air detection of the turbidity detector actually used,
Calculate the corrected resistance value A' of this turbidity detector when detecting the cleaning liquid at the beginning of washing using the formula B'-(B-A),
A washing machine characterized in that the correction resistance value of a resistor connected to at least one of the light emitting element and the light receiving element is adjusted to A' to correct the detection level.