Optical proximity sensor

Abstract

The present application provides an optical proximity sensor, including a first light source, a second light source, a light sensing module and a control unit. The first light source emits a first incident light to an object, and the object reflects a first reflected light. The second light source is arranged corresponding to the first light source, and emits a second incident light to the object, and the object reflects a second reflected light, wherein the traveling direction of the second incident light is opposite to the traveling direction of the first incident light. The light sensing module is located on the traveling path of the first reflected light and the traveling path of the second reflected light, and generates a first sensing signal and a second sensing signal according to the first reflected light and the second reflected light. The control unit is electrically connected to the first light source, the second light source and the light sensing module, and determines whether the object is located on one side of the first light source or on one side of the second light source according to the first sensing signal and the second sensing signal. Through the above configuration, objects approaching from two different directions can be sensed.

Description

Technical Field

[0001] The present application relates to the field of sensor technology, and in particular to an optical proximity sensor. Background Art

[0002] Optical proximity sensors are a type of contactless sensors that can sense the approach of objects or people without touching them, and are widely used in mobile phones and wearable devices.

[0003] Generally speaking, an optical proximity sensor includes a light emitting element and a sensing element. The light emitting element emits incident light to an object or a human body, and the incident light is reflected from the object or the human body as reflected light to the sensing element, and the sensing element generates a sensing signal based on the reflected light. The presence or absence of the sensing signal is used to determine whether the object or the human body is close to the sensing element. However, the existing light emitting element is incident in a single direction, and thus can only detect objects or human bodies approaching in a single direction, and cannot detect objects or human bodies approaching in directions other than the direction of the incident light. Utility Model Content

[0004] Based on the above, the present application provides an optical proximity sensor that can solve the problem of single direction detection.

[0005] Based on the above purpose, the present application provides an optical proximity sensor, including a first light source, a second light source, a light sensing module and a control unit. The first light source emits a first incident light to an object, and the object reflects a first reflected light. The second light source and the first light source are arranged corresponding to each other, and emit a second incident light to the object, and the object reflects a second reflected light, wherein the traveling direction of the second incident light is opposite to the traveling direction of the first incident light. The light sensing module is located on the traveling path of the first reflected light and the traveling path of the second reflected light, and generates a first sensing signal and a second sensing signal according to the first reflected light and the second reflected light. The control unit is electrically connected to the first light source, the second light source and the light sensing module, and determines whether the object is located on one side of the first light source or on one side of the second light source according to the first sensing signal and the second sensing signal.

[0006] In an embodiment of the present application, when the control unit receives the first sensing signal but does not receive the second sensing signal, the control unit determines that the object is located at one side of the first light source.

[0007] In an embodiment of the present application, when the control unit receives the second sensing signal but does not receive the first sensing signal, the control unit determines that the object is located at one side of the second light source.

[0008] In an embodiment of the present application, the light sensing module includes a first light sensing element and a second light sensing element. The first light sensing element generates a first sensing signal according to the first reflected light, and the second light sensing element generates a second sensing signal according to the second reflected light.

[0009] In an embodiment of the present application, the first light sensing element is spaced apart from the first light source, and the second light sensing element is spaced apart from the second light source.

[0010] In an embodiment of the present application, the optical proximity sensor further includes a body, and the first light source, the second light source, the light sensing module and the control unit are disposed in the body.

[0011] In an embodiment of the present application, the light emission wavelength of the first light source is different from the light emission wavelength of the second light source.

[0012] In an embodiment of the present application, the light sensing module is disposed between the first light source and the second light source.

[0013] In an embodiment of the present application, the optical proximity sensor further includes an ambient light sensing element, which is electrically connected to the control unit and generates and transmits an ambient light compensation signal to the control unit according to the ambient light of the environment surrounding the object. The control unit adjusts the first sensing signal and the second sensing signal according to the ambient light compensation signal.

[0014] In an embodiment of the present application, the light sensing module includes a filter circuit to filter the first sensing signal and the second sensing signal.

[0015] In summary, the optical proximity sensor of the present application can sense two objects approaching from different directions through the configuration of dual light sources and light sensing modules. In addition, the optical proximity sensor of the present application is further equipped with an ambient light sensing element and a filtering circuit to eliminate the interference of ambient light on reflected light and filter noise.

[0016] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application and implement it according to the contents of the specification, the present application is described in detail below with reference to the preferred embodiments of the present application and the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 FIG. 5 is a diagram showing a configuration of an optical proximity sensor according to an embodiment of the present application.

[0018] Figure 2A and Figure 2B The figure is a schematic diagram showing the operation of an optical proximity sensor according to an embodiment of the present application.

[0019] Figure 3 FIG. 5 is a diagram showing a configuration of an optical proximity sensor according to another embodiment of the present application.

[0020] Figure 4 The figure is a schematic diagram illustrating an optical proximity sensor applied to a conveyor belt according to an embodiment of the present application.

[0021] Description of reference numerals:

[0022] 1A, 1B: Optical proximity sensor

[0023] 10: First Light Source

[0024] 20: Second light source

[0025] 30: Light sensing module

[0026] 31: First light sensing element

[0027] 32: Second light sensing element

[0028] 33: Filter circuit

[0029] 40: Control unit

[0030] 50: Ambient light sensor

[0031] CV1: Conveyor belt

[0032] IL1: First incident light

[0033] IL2: Second incident light

[0034] MB1: Ontology

[0035] OB1: Object

[0036] RL1: First reflected light

[0037] RL2: Second reflected light DETAILED DESCRIPTION

[0038] The following is an explanation of the implementation of the present application by means of specific embodiments. People familiar with the technology can easily understand other advantages and effects of the present application from the contents disclosed in this specification.

[0039] It should be noted that, in the absence of conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The present application will be described in detail below with reference to the drawings and in combination with the embodiments. In order to enable those skilled in the art to better understand the present application scheme, the technical scheme in the embodiments of the present application will be clearly and completely described below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only embodiments of a part of the present application, not all embodiments. Based on the embodiments of the present application, all other embodiments obtained by ordinary technicians in the field without making creative work should fall within the scope of protection of the present application.

[0040] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0041] See also Figure 1 , which is a diagram illustrating the configuration of an optical proximity sensor according to an embodiment of the present application. Figure 1 As shown, the optical proximity sensor 1A comprises a first light source 10, a second light source 20, a light sensing module 30 and a control unit 40. The first light source 10 emits a first incident light IL1 to an object OB1. Figure 2A As shown, the first light source 10 is located on one side of the first light source 10 and reflects the first reflected light RL1 from the object OB1. The second light source 20 is arranged corresponding to the first light source 10 and emits the second incident light IL2 to the object OB1; wherein the traveling direction of the second incident light IL2 is opposite to the traveling direction of the first incident light IL1. At this time, the object OB1 is as shown in FIG. Figure 2B As shown, the object OB1 is located on one side of the second light source 20 and reflects the second reflected light RL2 from the object OB1. The light sensing module 30 is located on the travel path of the first reflected light RL1 and the travel path of the second reflected light RL2, and generates a first sensing signal and a second sensing signal according to the first reflected light RL1 and the second reflected light RL2. The control unit 40 is electrically connected to the first light source 10, the second light source 20 and the light sensing module 30, and determines whether the object OB1 is located on one side of the first light source 10 or the second light source 20 according to the first sensing signal and the second sensing signal. It should be noted that the object OB1 can be an object of any shape, such as a vehicle. In the following text, the number of objects OB1 is single, but it is not limited to this.

[0042] In the present embodiment, the optical proximity sensor 1A further includes a body MB1, a first light source 10, a second light source 20, a light sensing module 30, and a control unit 40 are disposed in the body MB1. Specifically, the body MB1 may be a cylinder, and the interior of the body MB1 has a containing space, the first light source 10 and the second light source 20 are disposed on the left and right sides of the body MB1, the light sensing module 30 and the control unit 40 are disposed in the containing space, and the control unit 40 is electrically connected to the first light source 10, the second light source 20, and the light sensing module 30 through a plurality of conductive wires.

[0043] In the present embodiment, the first light source 10 and the second light source 20 may be light-emitting diodes (LEDs) or lasers (Light Amplification by Stimulated Emission of Radiation, LASERs), and the light emission bands of the first light source 10 and the second light source 20 are both in the visible light band. The light emission wavelength of the first light source 10 is different from the light emission wavelength of the second light source 20; for example, the light emission wavelength of the first light source 10 is in the blue light band, and the light emission wavelength of the second light source 20 is in the red light band.

[0044] The light sensing module 30 is disposed between the first light source 10 and the second light source 20, and the projection of the light sensing module 30 on the circular bottom surface of the body MB1 is located between the projection of the first light source 10 on the circular bottom surface of the body MB1 and the projection of the second light source 20 on the circular bottom surface of the body MB1. The light sensing module 30 includes a first light sensing element 31 and a second light sensing element 32. The first light sensing element 31 is spaced apart from the first light source 10, and the sensing surface of the first light sensing element 31 faces the left side of the body MB1, and the first light sensing element 31 generates a first sensing signal according to the first reflected light RL1. The second light sensing element 32 is spaced apart from the second light source 20, and the sensing surface of the second light sensing element 32 faces the right side of the body MB1, and the second light sensing element 32 generates a second sensing signal according to the second reflected light RL2. The first light sensing element 31 and the second light sensing element 32 can be silicon sensors or infrared sensors.

[0045] The control unit 40 controls the first light source 10 and the second light source 20 to periodically emit the first incident light IL1 and the second incident light IL2, and the period of the first light source 10 emitting the first incident light IL1 may be different from the period of the second light source 20 emitting the second incident light IL2. For example, the control unit 40 controls the first light source 10 to emit the first incident light IL1 every 3 seconds, and the control unit 40 controls the second light source 20 to emit the second incident light IL2 every 2 seconds. The control unit 40 may be a microcontroller unit (MCU) or a programmable logic controller (PLC).

[0046] See also Figure 2A and Figure 2B , which is a schematic diagram illustrating the operation of an optical proximity sensor according to an embodiment of the present application. Figure 2AAs shown, the object OB1 is located on the left side of the body MB1, the first light source 10 emits the first incident light IL1 to the object OB1, the object OB1 reflects the first reflected light RL1 to the first light sensing element 31, and the first light sensing element 31 generates and transmits the first sensing signal to the control unit 40 according to the first reflected light RL1. At this time, the second incident light IL2 emitted by the second light source 20 does not enter the object OB1, and no second reflected light RL2 is generated, and the second light sensing element 32 does not generate the second sensing signal. Then, the control unit 40 receives the first sensing signal but does not receive the second sensing signal, and determines that the object OB1 is located on the side of the first light source 10 according to the first sensing signal.

[0047] Furthermore, the control unit 40 obtains the emission time of the first incident light IL1 and the reception time of the first reflected light RL1 from the first light source 10 and the first light sensing element 31, and calculates the distance between the first light sensing element 31 and the object OB1 according to the light speed corresponding to the first incident light IL1, the emission time of the first incident light IL1, and the reception time of the first reflected light RL1. In addition, the control unit 40 can also determine whether the object OB1 is close to the first light source 10 or far away from the first light source 10 according to the signal strength and the critical value of the first sensing signal. In detail, when the signal strength of the first sensing signal is greater than the first critical value, the control unit 40 determines that the object OB1 is close to the first light source 10; when the signal strength of the first sensing signal is less than the first critical value, the control unit 40 determines that the object OB1 is far away from the first light source 10.

[0048] like Figure 2B As shown, the object OB1 is located on the right side of the body MB1, the first incident light IL1 emitted by the first light source 10 does not enter the object OB1, and no first reflected light RL1 is generated, and the first light sensing element 31 does not generate a first sensing signal. At this time, the second light source 20 emits the second incident light IL2 to the object OB1, and the object OB1 reflects the second reflected light RL2 to the second light sensing element 32, and the second light sensing element 32 generates and transmits a second sensing signal to the control unit 40 according to the second reflected light RL2. Then, the control unit 40 receives the second sensing signal but does not receive the first sensing signal, and determines that the object OB1 is located on the side of the second light source 20 according to the second sensing signal.

[0049] Similarly, the control unit 40 obtains the emission time of the second incident light IL2 and the reception time of the second reflected light RL2 from the second light source 20 and the second light sensing element 32, and calculates the distance between the second light sensing element 32 and the object OB1 according to the light speed corresponding to the second incident light IL2, the emission time of the second incident light IL2, and the reception time of the second reflected light RL2. The control unit 40 can also determine whether the object OB1 is close to the second light source 20 or far away from the second light source 20 according to the signal strength of the second sensing signal and the second critical value. In detail, when the signal strength of the second sensing signal is greater than the second critical value, the control unit 40 determines that the object OB1 is close to the second light source 20; when the signal strength of the second sensing signal is less than the second critical value, the control unit 40 determines that the object OB1 is far away from the second light source 20.

[0050] See also Figure 3 , which is a configuration diagram of an optical proximity sensor according to another embodiment of the present application. Figure 3 As shown, the optical proximity sensor 1B includes a first light source 10, a second light source 20, a light sensing module 30, a control unit 40 and a body MB1. The configuration relationship between the first light source 10, the second light source 20, the light sensing module 30, the control unit 40 and the body MB1 has been described in detail. Figure 1 In the embodiment described, but Figure 3 The embodiment shown is Figure 1 The illustrated embodiment still has some differences: the light sensing module 30 includes a filter circuit 33 , and the optical proximity sensor 1B further includes an ambient light sensing element 50 .

[0051] The filter circuit 33 filters the first sensing signal and the second sensing signal to remove noise from the first sensing signal and the second sensing signal. When the object OB1 is located on the left side of the body MB1, the filter circuit 33 transmits the filtered first sensing signal to the control unit 40; when the object OB1 is located on the right side of the body MB1, the filter circuit 33 transmits the filtered second sensing signal to the control unit 40.

[0052] The ambient light sensing element 50 is electrically connected to the control unit 40 and senses the ambient light intensity of the surrounding environment of the object OB1. In other words, the ambient light sensing element 50 generates and transmits an ambient light compensation signal to the control unit 40 according to the ambient light (e.g., sunlight) of the surrounding environment of the object OB1. When the object OB1 is located on the left side of the body MB1, the control unit 40 performs a subtraction process on the filtered first sensing signal and the ambient light compensation signal to adjust the first sensing signal; when the object OB1 is located on the right side of the body MB1, the control unit 40 performs a subtraction process on the filtered second sensing signal and the ambient light compensation signal to adjust the second sensing signal.

[0053] See also Figure 4, which is a schematic diagram illustrating an optical proximity sensor applied to a conveyor belt according to an embodiment of the present application. Figure 4 As shown, Figure 1 The optical proximity sensor 1A shown is applied to a conveyor belt CV1. When an object OB1 moves from the left side of the conveyor belt CV1 to the bottom of the optical proximity sensor 1A, the first light source 10 emits a first incident light IL1 to the object OB1. Due to the moving state of the object OB1, the first light sensing element 31 receives a plurality of first reflected lights RL1 reflected from the object OB1 at a plurality of time points, and generates and transmits a plurality of first sensing signals to the control unit 40 according to the plurality of first reflected lights RL1. The control unit 40 determines that the object OB1 is approaching the first light source 10 according to the signal strength of the plurality of first sensing signals.

[0054] When the object OB1 is located below the optical proximity sensor 1A, the first incident light IL1 emitted by the first light source 10 and the second incident light IL2 emitted by the second light source 20 are not incident on the object OB1, and the first light sensing element 31 and the second light sensing element 32 do not generate the first sensing signal and the second sensing signal. When the object OB1 moves from below the optical proximity sensor 1A to the right side of the conveyor belt CV1, the second incident light IL2 emitted by the second light source 20 is incident on the object OB1. Due to the moving state of the object OB1, the second light sensing element 32 receives a plurality of second reflected lights RL2 reflected from the object OB1 at a plurality of time points, and generates and transmits a plurality of second sensing signals to the control unit 40 according to the plurality of second reflected lights RL2. The control unit 40 determines that the object OB1 is away from the second light source 20 according to the signal strength of the plurality of second sensing signals.

[0055] In summary, the optical proximity sensor of the present application can sense two objects approaching from different directions through the configuration of dual light sources and light sensing modules. In addition, the optical proximity sensor of the present application is further equipped with an ambient light sensing element and a filtering circuit to eliminate the interference of ambient light on reflected light and filter noise.

Claims

1. An optical proximity sensor, characterized in that: include: A first light source emits a first incident light to an object, and the object reflects a first reflected light; A second light source is disposed corresponding to the first light source and emits a second incident light to the object, and the object reflects a second reflected light, wherein the traveling direction of the second incident light is opposite to the traveling direction of the first incident light; A light sensing module is located on a travel path of the first reflected light and on a travel path of the second reflected light, and generates a first sensing signal and a second sensing signal according to the first reflected light and the second reflected light; as well as The control unit is electrically connected to the first light source, the second light source and the light sensing module, and determines whether the object is located at one side of the first light source or one side of the second light source according to the first sensing signal and the second sensing signal.

2. The optical proximity sensor according to claim 1, wherein: When the control unit receives the first sensing signal but does not receive the second sensing signal, the control unit determines that the object is located at one side of the first light source.

3. The optical proximity sensor according to claim 1, wherein: When the control unit receives the second sensing signal but does not receive the first sensing signal, the control unit determines that the object is located at one side of the second light source.

4. The optical proximity sensor according to claim 1, wherein: The light sensing module includes a first light sensing element and a second light sensing element. The first light sensing element generates the first sensing signal according to the first reflected light, and the second light sensing element generates the second sensing signal according to the second reflected light.

5. The optical proximity sensor according to claim 4, wherein: The first light sensing element is spaced apart from the first light source, and the second light sensing element is spaced apart from the second light source.

6. The optical proximity sensor according to claim 1, wherein: It further includes a body, and the first light source, the second light source, the light sensing module and the control unit are disposed on the body.

7. The optical proximity sensor according to claim 1, wherein: The light emission wavelength of the first light source is different from the light emission wavelength of the second light source.

8. The optical proximity sensor according to claim 1, wherein: The light sensing module is disposed between the first light source and the second light source.

9. The optical proximity sensor according to claim 1, wherein: The device further includes an ambient light sensing element, which is electrically connected to the control unit and generates and transmits an ambient light compensation signal to the control unit according to the ambient light of the surrounding environment of the object. The control unit adjusts the first sensing signal and the second sensing signal according to the ambient light compensation signal.

10. The optical proximity sensor according to claim 1, wherein: The light sensing module includes a filter circuit to filter the first sensing signal and the second sensing signal.

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