KR20220147761A - Optical object detection sensor with improved performance and home appliance including the same - Google Patents

Abstract

The present invention relates to an optical object detection sensor with improved performance and a home appliance including the same and, more specifically, to a reflection-type optical object detection sensor with an improved environmental characteristic and a home appliance including the same. According to the present invention, a reflection-type optical sensor comprises: a light emitting element; a light receiving element in which light emitted from the light emitting element is reflected from a detection member and is incident; and a control unit which sets reference output by using a light receiving element output value input from the light receiving element during a reference output setting period and determines the existence of the detection member by using real-time output from the light receiving element and the reference output. Accordingly, the new high-performance optical sensor may overcome those limitations of existing optical sensors that restrict their use to controlled environments.

Description

Optical object detection sensor with improved performance and home appliance including the same

The present invention relates to an optical object detection sensor with improved performance and a home appliance including the sensor, and more particularly, to an optical reflection type object detection sensor with improved environmental characteristics and a home appliance including the same.

As shown in FIG. 1 , the reflective optical sensor 10 includes a light emitting device 62 emitting light, a light receiving device 64 receiving light, and the light emitting device 62 and the light receiving device 64 . Lenses 50a and 50b arranged on the front side to amplify light are used as a basic configuration.

The light emitting element 62 and the light receiving element 64 are fixed to the substrate 60, and when a current is supplied according to a pre-programmed program, the light emitting element 62 emits light, and the emitted light is condensed by the lens 50a. After being detected, it is emitted to the sensing area where the sensing member 70 to be sensed is located, and when the sensing member 70 is located in the sensing area, the reflected light that collides with the sensing member 70 and is reflected is incident on the light receiving element 64 . It is detected whether the sensing member 70 is present in the sensing area by measuring the amount of light produced, and a lens 50b is installed on the front surface of the light receiving element 64 to collect the reflected light that is reflected by hitting it.

An optical semiconductor chip such as a photodiode that emits current when light is incident is installed inside the light receiving element 64 . The current emitted from the optical semiconductor chip is changed and amplified into a voltage, and when the amount of light exceeds a predetermined reference value through the amplified voltage signal, it is determined that the reflected light has flowed into the sensing member 70, and the amount of light does not exceed the predetermined reference value. If not, it is determined that the sensing member 70 is not present.

Such a reflective optical sensor has the advantage of a simple structure and low price, but since the amount of reflected light varies when the position of the sensing member 70 is changed, the sensing area is narrow and the reflection from the sensing member 70 is changed. When the amount of reflected light is not constant, for example, when the shape of the sensing member 70 is different and/or the material of the sensing member 70 is different, there is an error in sensor recognition for the presence or absence of the sensing member 70 . is more likely to occur

In addition, when light is incident on the light receiving element even in the absence of the sensing member 70 , for example, disturbance light emitted from another light source is incident or reflected to an object other than the sensing member 70 . When the received light is incident, the possibility of an error occurring in the recognition process of the sensing member 70 increases.

Therefore, the conventional reflective optical sensor has a disadvantage that the sensing member 70 having the same amount of reflected light is reflected at the same position, and it can be used only in a controlled environment where there is no disturbance light or other reflected light.

In addition, in spite of such controlled environmental control, the probability of errors occurring as the light-emitting and light-receiving elements change their own characteristics due to external environments such as a decrease in output due to long-term use of the light-emitting and light-receiving elements and temperature and humidity increases.

The problem to be solved in the present invention is to overcome the limitations of the existing optical sensor that the sensing member having the same amount of reflected light is reflected at the same location and can be effectively used only in a controlled environment where there is no disturbance light or other reflected light. It is to provide a new high-performance optical sensor.

Another problem to be solved by the present invention is to overcome the limitations of the existing optical sensor that the sensing member having the same amount of reflected light is reflected at the same location, and can be effectively used only in a controlled environment where there is no disturbance light or other reflected light. It is to provide a new measurement method.

Another object to be solved by the present invention is to provide a new high-performance optical sensor and a measuring method that can solve the performance degradation caused by the usage period and environmental change of the reflective optical sensor.

Another problem to be solved by the present invention is to provide a foot sensor including an optical sensor that can be used in various environments.

Terms

In the present specification, the term 'reference value' means a measured value of an electrical signal output from the reflective sensor in the absence of a sensing object in the environment and/or place where the reflective sensor is installed.

In the specification of the present invention, the term 'reference output setting period' means a time period for obtaining a plurality of reference values.

solution

In order to solve the above problems, the present invention

light emitting element;

a light receiving element in which the light emitted from the light emitting element is reflected and incident on the sensing member; and

During the reference output setting period, the reference output is set using the light receiving element output value input from the light receiving element, and

A control unit that determines the presence of a sensing member using a real-time output and a reference output output from the light-receiving element

It provides a reflective optical sensor comprising a.

In the present invention, the reference output may be a plurality of reference values obtained during the reference output setting period, or a processed value, for example, statistical values of reference values. In an embodiment of the present invention, the statistical value may include an average, a square average, or a standard deviation of a plurality of reference values.

In one embodiment of the present invention, the reference output may be an average value of a plurality of reference values obtained during a reference output setting period.

In the present invention, the reference output may be updated at any time to reflect changes in the use environment and device characteristics over time. In an embodiment of the present invention, the update time may be performed after a predetermined time elapses after the last update. The predetermined time after the update may be 12 hours, 24 hours, a week, or a month.

In the present invention, the real-time output may be an output obtained outside the reference output setting period.

In the present invention, the control unit may have a determination criterion consisting of a real-time output value and a reference value to determine the presence or absence of a sensing object.

In an embodiment of the present invention, the controller may determine the presence or absence of a sensing object using a difference between one or more real-time output values and a reference output formed of an average value of a plurality of reference values.

In one embodiment of the present invention, the control unit is a sensing object when one or more real-time output values are out of a specific range, for example, 3% above and below the reference output, with respect to a reference output made of an average value of a plurality of reference values. can be determined to exist.

In another embodiment of the present invention, when the difference between the reference outputs is greater than the standard deviation of the plurality of reference values, twice the standard deviation, three times the standard deviation, or four times the standard deviation, the sensing object can be determined to exist.

The present invention in one aspect,

a light emitting device,

a light receiving element in which the light emitted from the light emitting element is reflected and incident on the sensing member; and

providing a reflective photosensor including a control unit for determining whether an object exists by using an output value output from the light receiving element;

setting, by the control unit, a reference output using a light-receiving element output value input from the light-receiving element during a reference output setting period; and

and determining, by the control unit, the presence of a sensing member using a real-time output and a reference output output from the light-receiving element.

The present invention in one aspect,

light emitting element;

a light receiving element in which the light emitted from the light emitting element is reflected and incident on the sensing member; and

During the reference output setting period, the reference output is set using the light receiving element output value input from the light receiving element, and

A reflective optical sensor is installed on the lower surface of the device, including a control unit for determining the presence of a sensing member using the real-time output and the reference output output from the light-receiving element,

The reflective optical sensor provides a device, characterized in that for detecting the presence or absence of a foot between the bottom surface of the device.

In the present invention, when the control unit detects the presence of the foot, the control unit may transmit a signal to the refrigerator control unit and activate a predetermined function in the refrigerator according to the signal. A function activated in the refrigerator according to the signal may be opening and closing of a refrigerator door.

The present invention in one aspect,

operating the photosensor;

determining a reference value of the optical sensor by converting the operated optical sensor output value into data;

Comparing the reference value of the optical sensor with the real-time data value, determining whether an object is an object; provides an object detection method comprising.

According to the present invention, a new high-performance optical sensor capable of overcoming the limitations of the existing optical sensor that can be effectively used only in a controlled environment has been provided.

An object of the present invention is to provide a new measurement method that can overcome the limitations of the existing optical sensor that can be effectively used only in a controlled environment.

According to the present invention, a novel high-performance optical sensor capable of overcoming changes in sensor characteristics over time has been provided.

In addition, the present invention provides a foot sensor that can be used in various environments.

1 is a view showing a reflective sensor according to the prior art.
2 is a view showing a reflective sensor according to the present invention.
3 is a view showing a state in which the reflective sensor according to the present invention is installed on the floor of the refrigerator to detect the feet.
4 is a view showing a flowchart for foot detection by the reflective sensor according to the present invention.
5 is a diagram showing a circuit of a reflective sensor according to the present invention.

Hereinafter, the present invention will be described in detail through examples. The following examples are not intended to limit the present invention, but to illustrate the present invention.

As shown in FIG. 2 , the reflective optical sensor 100 according to the present invention includes a rectangular printed circuit board 111 , a connector 112 installed in the center of the upper surface of the printed circuit board 111 , and a connector ( The light emitting element 113 mounted on one side of the printed circuit board 111 on one side of the 112 and the light receiving element 114 mounted on the upper surface of the printed circuit board 111 on one side of the connector 112, the printed circuit board 111 ) and a detector unit 110 composed of an MCU 300 installed on the lower surface of the substrate, and a lens plate 121 in a rectangular shape. A light emitting lens 122 formed on one side of the lower surface of the lens plate 121 and condensing the light of the light emitting element, a light receiving lens 123 for condensing the light reflected on the other side of the lower surface of the lens plate 121, and a lens; The lens unit 120 made of the binding protrusions 124 formed on both ends of the lower surface of the plate 121 and the light emitting forming an optical path from the light emitting element 113 to the light emitting lens 122 on one side of the inner side in a rectangular parallelepiped shape. A light-receiving passage 132 forming an optical path from the light-receiving lens 123 to the light-receiving element 114 on the other side of the passage 131 , and an internal barrier rib forming the light-emitting passage 131 and the light receiving passage 132 . 133, the lower surface has a detector receiving portion 134 in which the detector unit 110 is accommodated, the upper surface has a lens receiving portion 135 so that the lens unit 120 is coupled, and both sides are coupled for fixing It consists of a housing part 130 in the form of a rectangular parallelepiped in which the piece 136 is formed.

The light emitting device 113 is an infrared light emitting device that emits infrared light instead of visible light so as not to be affected by changes in ambient illuminance, and the light receiving device 114 includes an infrared light receiving device capable of outputting a signal using infrared light. . The light receiving element 114 has a shield or a filter to prevent infrared light other than the infrared light reflected from an object or floor in the sensing area from being introduced.

In the MCU 300 of the detector unit, the voltage output from the amplified light receiving element 114 is converted into a digital form through an analog-to-digital converter, and then a storage unit 310 is stored and a processing unit 320 that processes the stored signal. and a determination unit 330 that determines whether over-detection is detected.

As shown in FIGS. 2 and 3 , in the reflective optical sensor 100 according to the present invention, the separation legs 220 of the refrigerator 200 are installed and are spaced apart from the bottom surface 210 by a predetermined interval, and the lower surface The upper surface of the lens plate 120 of the reflective optical sensor 100 is fixed to face the bottom surface 210 on which the refrigerator 200 is installed, and the fixing hole 137 formed in the fixing coupling piece 136 is inserted into the Fasten the screws and fasten.

Daverage creation

2 to 4, when the sensor is operated in a state in which the reflective optical sensor 100 according to the present invention is installed on the bottom surface 210 of the refrigerator 200, the reflective optical sensor ( 100) is generated.

When the operation of the reflective photosensor 100 starts, power is applied to the light emitting device 113 to emit light from the light emitting device 113 . The light emitted from the light emitting device 113 passes through the light emitting passage 131 , passes through the light emitting lens 122 formed on the lower surface of the lens plate 121 , and is focused and then irradiated to the sensing area S.

Since there is no sensing object in the sensing area S at the initial installation stage, the light emitted from the light emitting device 113 is reflected on the bottom surface where the refrigerator 200 is installed, and then the lens plate 121 and the light receiving lens formed on the lower surface of the lens plate. It is incident on the light receiving element 114 via (123).

When the light reflected from the floor is incident on the light receiving element 114 , a current is output from a light receiving chip such as a photodiode or a photo transistor mounted inside the light receiving element 114 . The current output from the light receiving chip is amplified in the form of a voltage to output a first output voltage.

The amplified first output voltage is input to the MCU 300 attached to the printed circuit board 111 , and is converted into a digital form through an analog-to-digital converter, and then the first measurement time as a first reference value of the MCU 300 . It is stored in the reference value storage unit 310 together with (T1).

When the first reference value D1 is stored in the storage unit 310 together with the first measurement time, power is applied to the light emitting device again, and the light reflected from the bottom is inputted to the light receiving device 114 and the light receiving device 114 . ), the second output voltage is output.

The amplified second output voltage is input to the MCU 300 attached to the printed circuit board 111 , converted into a digital form through an analog-to-digital converter, and then converted into a second reference value D2 of the MCU 300 . 2 is stored in the reference value storage unit 310 together with the measurement time T2.

This process is repeated for a predetermined reference output setting period Ta, and is stored in the reference value storage unit 310 together with the measurement time Tn as the nth reference value Dn when the reference output setting period ends.

When the reference output setting period Ta elapses, the MCU 300 processes the n reference values stored in the reference value storage unit 310 in the processing unit 320 in the form of statistical values, and determines the processed statistical values by the determination unit 330 . save to In one embodiment, the processed statistical value is Daverage, which is an average of n reference values stored in the reference value storage unit 310 . The variance and standard deviation for n reference values may be stored together with the Daverage.

Daverage varies depending on the environment in which the refrigerator 200 is installed. In the case of a floor material with high reflectivity, high output is input during the reference output setting period (Ta), so Daverage has a relatively high value. Since a low output is input during Ta), Daverage has a relatively low value.

judgment

After Daverage is set, the actual measurement of the reflective optical sensor 100 is started. When the measurement starts, power is applied to the light emitting device 113 to emit light from the light emitting device 113 . The light emitted from the light emitting device 113 passes through the light emitting passage 131 , passes through the light emitting lens 122 formed on the lower surface of the lens plate 121 , is condensed, and then is irradiated to the sensing area 150 .

If there is no sensing object in the sensing area S, the light emitted from the light emitting device 113 is reflected on the floor where the refrigerator 200 is installed in the same way as when measuring the reference value, and then the lens plate 121 and the lens plate It is incident on the light receiving element 114 through the light receiving lens 123 formed on the lower surface.

If there is a sensing object, for example, a foot in the sensing area S, the light emitted from the light emitting device 113 is reflected by the foot input into the gap between the bottom and the bottom of the refrigerator 200, and then the lens It is incident on the light receiving element 114 through the plate 121 and the light receiving lens 123 formed on the lower surface of the lens plate.

When the light reflected from the floor or feet is incident on the light receiving element 114 , a current is output from a light receiving chip such as a photodiode or phototransistor mounted inside the light receiving element 114 . The current output from the light-receiving chip is amplified and output in the form of a voltage. The amplified output voltage is input to the MCU 300 attached to the printed circuit board 111, is converted into a digital form through an analog-to-digital converter, and is then converted to an actual measured value (Dt, where t is the measurement time) by a determination unit ( 330) and contrasted with the reference value (Daverage).

The determination unit 330 compares the measured value (Dt) with the reference value (Daverage), and if the difference exceeds a preset allowable range, it is determined that a foot has entered between the lower part of the refrigerator and the floor surface and outputs a corresponding signal, and the difference is the standard If it is inside, it is determined that a foot has not entered between the lower part of the refrigerator and the floor, and a corresponding signal is output.

The preset tolerance range is within ±10% of the reference value (Daverage), for example, ±10%, ±9%, ±8%, ±7%, ±6%, ±5%, ±4%, ±3 or set to %. It is set to a multiple of the standard deviation, for example, 2x, 3x, 4x, 5x, or 6x the standard deviation.

Daverage update

Daverage is updated to respond to changes in the installation environment, for example, a refrigerator installation location, a floor type, a change in the distance between the refrigerator and the floor, and a change in characteristics of measuring equipment according to aging.

Daverage is updated at a preset cycle, for example, 1 hour, 1 day, 1 week, 1 month, or 1 year. For the update according to time, the update time is determined by using the elapsed time after the Daverage measurement or by using a separate time timer.

Daverage considers that the refrigerator is substantially operated with constant power, and when there is a signal to turn on/off the power, it is determined that there is a position adjustment of the refrigerator, and the update is performed regardless of a preset period.

When the Daverage is updated, the existing Daverage stored in the reference value storage unit 310 is deleted, and the determination unit 330 compares the updated Daverage_update with the measured data.

100: reflective optical sensor
113: light emitting element
114: light receiving element
121: lens plate
122: luminous lens
123: light receiving lens
200: refrigerator
300 : MCU

Claims (13)

light emitting element;
a light receiving element in which the light emitted from the light emitting element is reflected and incident on the sensing member; and
a control unit configured to set a reference output using a light receiving element output value input from the light receiving element during a reference output setting period, and determining the presence of a sensing member using a real-time output and a reference output output from the light receiving element;
A reflective optical sensor comprising a. According to claim 1,
and the reference output is a statistical value of a plurality of reference values obtained during the reference output setting period. 3. The method of claim 1 or 2,
and the reference output is an average of a plurality of reference values obtained during the reference output setting period. 3. The method of claim 1 or 2,
The reflective optical sensor, characterized in that the reference output is updated at a predetermined time interval. 3. The method of claim 1 or 2,
The reference output is a reflective optical sensor, characterized in that it is updated by power on/off. 3. The method of claim 1 or 2,
The control unit is a reflective optical sensor, characterized in that it comprises an MCU. 7. The method of claim 1 or 6,
The control unit is a reflective optical sensor, characterized in that it comprises a storage unit, a processing unit and a determination unit. Providing a reflective optical sensor comprising: a light emitting element; a light receiving element in which light emitted from the light emitting element is reflected by a sensing member to be incident; step;
setting, by the control unit, a reference output using a light-receiving element output value input from the light-receiving element during a reference output setting period; and
determining, by the controller, the presence of a sensing member using a real-time output and a reference output output from the light-receiving element
A sensing method using a reflective optical sensor comprising a. 9. The method of claim 8,
The reference output is a sensing method using a reflective optical sensor, characterized in that the time is updated by a predetermined time interval and/or an on/off signal. light emitting element; a light receiving element in which the light emitted from the light emitting element is reflected and incident on the sensing member; and a control unit configured to set a reference output using the light receiving element output value input from the light receiving element during the reference output setting period, and to determine the presence of the sensing member using the real-time output and the reference output output from the light receiving element. A reflective optical sensor is installed on the lower surface,
The reflective optical sensor is a refrigerator, characterized in that for detecting the presence or absence of a foot between the bottom surface of the device. 11. The method of claim 10,
Refrigerator, characterized in that when detecting the presence of the foot, the control unit transmits a signal to the refrigerator control unit, and activates a predetermined function in the refrigerator according to the signal. 12. The method of claim 10 or 11,
The reference output is an average of a plurality of reference values obtained during the reference output setting period. 13. The method of claim 12,
The reference output is a reflective optical sensor, characterized in that it is updated after a predetermined time or after an on/off signal of the power source.

Images