JPH0442036B2 - - Google Patents

Description

Detailed Description of the Invention (Industrial Application Field) The present invention uses a photocoupler consisting of a light-emitting element and a light-receiving element as a detector to detect the turbidity of washing liquid and rinsing liquid. The present invention relates to a washing machine control device that controls a washing machine.

(Configuration of conventional example and its problems) Conventionally, as a method for detecting the degree of cleanliness of washing liquid,
There is a method for detecting the degree of dirt (turbidity) in washing liquid, and the turbidity is measured using a light-emitting element and a light-receiving element. However, depending on the type of detergent, the amount of detergent, the degree of dirtiness of the laundry, etc., it may be difficult to detect changes in turbidity, and it is necessary to change the sensitivity of the detector. Furthermore, since the turbidity in the washing process and the turbidity in the rinsing process are different, it is necessary to change the sensitivity depending on the process. In addition, the output voltage of the light receiving element of the detector is generally measured using a smoothing capacitor, since the light transmittance changes slightly due to the influence of liquid dirt and bubbles.
A method is used for detection by smoothing the output voltage waveform of the output device. However, in order to switch the sensitivity of the detector between two or more stages and set the amount of light emitted from the light emitting element to an appropriate detectable sensitivity, it takes time to switch the sensitivity due to the time constant caused by the smoothing capacitor. However, the drawback was that it was not possible to set an appropriate light output in a short period of time.

(Object of the Invention) The object of the present invention is to solve the conventional drawbacks and to provide a method for switching the sensitivity of a detector in multiple stages. The purpose of the present invention is to provide a control device for the following.

(Structure of the Invention) The washing machine control device of the present invention includes a detector that detects the turbidity of washing liquid, a light emission output switching section that switches the light emission output of the detector in multiple stages, and a light emission output switching section that smooths the output of the detector. A smoothing section for controlling the smoothing section and a transistor for controlling the capacitor in the smoothing section are connected in series with the capacitor, and when setting the light emission output, the transistor is connected in series to the capacitor.
OFF, increase the light emission output by sequentially switching the light emission output switching section, compare the smoothing section output voltage at that time with a preset reference voltage, and check if the output voltage of the detector has become higher than the reference voltage. The light emission output at the time is used as the light emission output for measuring the change in turbidity of the liquid, and the transistor is controlled to be in the ON state.

(Description of Embodiment) An embodiment of the present invention will be described based on FIGS. 1 to 4.

In FIG. 1, 1 is the main body of the washing machine, 2 is an outer tub supported by a suspension 3, and 4 is an inner tub for washing clothes, which has a large number of holes 5 in the wall surface.
6 is a pulsator that stirs the clothes in the inner tank 4. Reference numeral 7 denotes a mechanism case housing a built-in brake and clutch mechanism, and 8 a motor, which repeatedly rotates forward and reverse during washing and rinsing, and rotates the pulsator 6 via the clutch mechanism. 9 is a drain valve, which is open during the washing, rinsing, and water supply processes. Between the drain valve 9 and the bottom of the outer tank 2,
A drainage path 10 is formed in a pipe shape and made of a translucent material. 11 is a drain hose connected to the drain valve 9. 12 is a detector provided in the drainage path 10. The detector has
A light-emitting element consisting of a light-emitting diode and a light-receiving element consisting of a transistor are sandwiched between a drainage path 10 and are configured to face each other, and between the light-emitting element and the light-receiving element, washing liquid and rinsing liquid can freely enter and exit. It is becoming.

FIG. 2 shows a control circuit mainly including a detector 12, 13 is a light emitting element, 14 is a light receiving element, the light emitting output of the light emitting element 13 passes through the medium of washing liquid, is attenuated, and reaches the light receiving element 14. Light reception output voltage is generated. Reference numeral 15 denotes a light emitting output switching unit that switches the light emitting output of the light emitting element 13. When the light transmittance of the washing liquid is poor, the light receiving output power becomes low and it becomes difficult to detect the rate of change in light transmittance, so the light emitting output is changed. By increasing the voltage, the light receiving output voltage becomes high, and changes in light transmittance can be detected. This is generally expressed as the received light output voltage V ₀ =A·P ₀ ·l ⁻ 〓〓. Note that V ₀ is the light receiving output voltage, P ₀ is the light emission output of the light emitting element 13, and μ
is the light attenuation coefficient (corresponds to the turbidity of the washing liquid) A,
B is a coefficient. The slight change in the received light output voltage with respect to turbidity μ is dV ₀ /dμ = A・B・P ₀・l ^- 〓〓,
As the turbidity μ increases, it becomes difficult to detect changes in the received light output voltage. By increasing the light emitting output _P0 , the light receiving output voltage change dv/dμ also increases,
It is possible to increase the change in the received light output voltage with respect to the turbidity μ. Note that the light emission output switching section 15 is composed of resistors, R ₁ , R ₂ , R ₃ and transistors Q ₁ , Q ₂ , Q ₃ . Reference numeral 16 denotes a smoothing section. Since the output voltage of the detector 12 fluctuates slightly due to the state of the washing liquid and the influence of bubbles, etc., the time constant formed by resistor _R5 and capacitor C smooths it out and eliminates the effects of slight fluctuations. . 17 is a DA converter that converts digital values into analog values. Reference numeral 18 denotes a comparison section that compares the output voltage V ₁ of the smoothing section 16 and the output V ₁ of the D-A conversion section 17.
When V ₁ > V ₂ , the output of the comparator 18
V ₃ is a low level signal, and when V ₁ < V ₂ a high level signal is output. 19 is an operation control section, and a light emission output switching section 1
5 and the transistor _Q4 of the smoothing section 16, and controlling the D-A converting section 17.
Although not shown, it is a control unit that controls the operations of motors, displays, stitches, etc. via an interface circuit, and is composed of a CPU, ROM, RAM, input and output ports, etc.

The current I flowing through the light emitting element 13 is I ₁ = when the transistor Q ₁ of the light emission output switching unit 15 is turned on.
V−V _F /R ₁ (V _F is the forward voltage of the light emitting element 13), and similarly when only Q ₂ is turned on, I ₂ =
When only V-V _F /R ₂ and Q ₃ are turned on, I ₃ = V-V _F /R ₃ , and if R ₁ > R ₂ > R 3, I ₁ < I ₂ < _{I 3} Therefore, the current flowing through the light emitting element 13 can be switched by turning Q ₁ , Q ₂ , and Q ₃ ON and OFF, and the light emission output can be increased or decreased. This light emitting element 13
The light emitting output reaches the light receiving element 14, the collector current flows through the resistor _R4 , and the light receiving output _V0 is generated. The relationship between the received light output V ₀ and the output voltage V ₁ of the smoothing section 16 is shown in Figure 3 a, b, and c, where V ₀ has a step characteristic and V ₁ has a transient characteristic when the transistor Q ₄ is ON. It takes a considerable amount of time (more than the time constant R ₆ ×C) for V ₁ to reach the saturation voltage. When the light emitting output (b) in FIG. 3 is sequentially increased and comparing whether the light receiving output has reached a preset voltage V ₂ or higher, when compared with the output voltage V ₁ of the smoothing section 16, V ₁
Since the comparison needs to be made after reaching the saturation voltage of , it takes time to set the light emission output.
The characteristic diagram shown in Fig. 3c is a diagram when the transistor _Q4 of the smoothing section 16 is turned off by the signal from the operation control section 19 to eliminate the influence of the smoothing capacitor C, and _V0 and _V1 are the same. waveform, and there is no delay in the transfer characteristic of V ₀ to V ₁ , and the set voltage V ₂ is changed in a short time.
The target light output can be set by sequentially switching the light emission output.

Figures 4a, b, and c are characteristic diagrams for explaining the operation, and when setting the light emission output, the transistor
When Q ₄ is turned OFF, the light emission output is increased by one step at time t ₁ , and the comparison voltage with the output voltage V ₁ of the smoothing section 16 is set to 2.5V, for example, the DA converter 17 converts V ₂ = 2.5V. The comparator 18 compares V ₁ and V ₂ , and if V ₁ <V ₂ , the output of the comparator 18 becomes a high level, and the operation control unit 19 determines that V ₁ <V ₂ .
Next, at time _t2 , the light emission output is increased by one step and the same process is performed. When V ₁ > V ₂ , the output of the comparison section 18 becomes a low level, and the operation control section 19 determines that V ₁ > V ₂ , and uses the luminous output at this time to determine the turbidity of the washing liquid. is set to the set value, and the light emission output setting process is ended. Next, at time _t4 , the transistor _Q4 of the smoothing section 16 is turned on, the smoothing capacitor C is operated, and the output voltage _V1 of the detector 12 is changed to the time constant
Smooth the waveform with a smoothing circuit of R ₆ ×C and measure the turbidity of the washing liquid.

(Effects of the Invention) According to the present invention, when detecting a change in turbidity of a liquid by switching the light emission output of the detector in multiple stages and smoothing the output voltage of the detector, the cost is low and the number of parts is reduced. The effect is that it is possible to obtain a detector sensitivity switching device that can achieve the desired light emission output in a short time with a small amount of light emission.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a washing machine equipped with a control device according to an embodiment of the present invention, FIG. 2 is a circuit diagram of the same control device, and FIGS. Similarly, FIGS. 4a, b, and c are waveform diagrams of the detector and comparator of the control device. 1...Washing machine body, 2...Outer tub, 3...Suspension, 4...Inner tub, 5...Hole, 6...Pulsator, 7...Mechanism case, 8...Motor, 9...
...Drain valve, 10...Drain path, 11...Drain hose, 12...Detector, 13...Light emitting element, 1
4... Light receiving element, 15... Light emission output switching unit, 16
...Smoothing section, 17...D-A conversion section, 18...Comparison section, 19...Operation control section, R1 _, R2 _{, R3} , _R4 ,
_R5 ...Resistor, _Q1 , _Q2 , _Q3 , _Q4 ...Transistor, C...Capacitor, _V0 , _V1 , _V2 , _V3 ...Output voltage.

Claims (1)

[Claims] 1. A detector that includes a light-emitting element and a light-receiving element facing each other and detects the turbidity of the washing liquid and rinsing liquid based on the light transmittance, and a light-emission output switching unit that switches the light-emission output of the detector into multiple stages. and a smoothing section consisting of a capacitor and a resistor for smoothing the output voltage of the detector, a transistor for controlling the operation of the capacitor is connected in series with the capacitor, and when setting the light emitting output switching, When measuring changes in liquid turbidity with the transistor turned off,
A washing time or rinsing time control device for a washing machine, characterized in that the transistor is controlled to be in an ON state.