KR20190010305A - Optical sensor device with optical structure for noise reduction and electronic device including the same - Google Patents

Abstract

The present invention relates to an optical sensor device for having an optical structure for reducing a noise by a Fresnel-loss generated on a transparent window surface contacted by a body surface of a user. According to an embodiment of the present invention, the optical sensor device comprises: a transparent window including a first surface toward an outside of the optical sensor device and a second surface opposite to the first surface; and optical sensor including a light detector receiving light through a light source emitting the light toward the transparent window and the transparent window and arranged to be spaced by a regular interval from the second surface of the transparent window. The transparent window can include a convex lens protruded toward the optical sensor in at least a part of the second surface.

Description

TECHNICAL FIELD [0001] The present invention relates to an optical sensor device having an optical structure for reducing noise, and an electronic device including the optical sensor device. [0002]

Various embodiments of the disclosure relate to an optical sensor device having an optical structure for reducing noise and an electronic device including the same.

Recently, as the interest in health has increased, the portable electronic device has a function of detecting various information of the body and checking the health state of the body. The user can easily and conveniently measure various biological signals such as heart rate, blood pressure and the like without using a complicated separate detection device by using such a portable electronic device. Particularly, the biometric information measurement function can be mounted on a portable electronic device, for example, a wearable device such as a smart watch. The smart watch can monitor the vital signs of the wearer and inform the user of the health status in real time.

In a conventional portable electronic device, pulse-wave analysis (PWA) based on optical signals, which detects blood flow changes synchronized with the heartbeat, is a method of non-invasively measuring the cardiovascular characteristics of the user, ) Method is used. In the PWA method, light of an appropriate wavelength is irradiated to the surface of a body such as a finger or a wrist using an optical sensor, and the shape of a photo-plethysmoGraph (PPG), for example, And the intensity is measured according to the change in blood flow of the subject.

It is important for the vein wave system to have a clear waveform in order to increase the accuracy of the heart rate measurement by analyzing the pulse waveform based on the optical signal for heart rate measurement. Therefore, it is important to minimize noise other than the PPG signal that is effective in the reflected light detected by the photodetector.

The optical sensor device according to various embodiments of the present disclosure may include an optical structure for reducing noise due to fresnel-loss occurring on the surface of a transparent window on which a user's body surface contacts.

An optical sensor device according to an embodiment of the present disclosure includes: a transparent window including a first surface facing the outside of the optical sensor device and a second surface facing the first surface; And an optical sensor that includes a light source that emits light toward the transparent window and a light detector that receives light through the transparent window and is spaced apart from the second surface of the transparent window by a predetermined distance, And a convex lens protruding from the at least part of the second surface toward the optical sensor.

An electronic device according to one embodiment of the present disclosure includes: a transparent window including a first surface facing outwardly of the electronic device and a second surface facing the first surface and being fixedly coupled to an outer housing of the electronic device; A light source for emitting light toward the transparent window and a photodetector for receiving light reflected from an external object in contact with the first surface of the transparent window, An optical sensor disposed on an internal circuit board of the electronic device; And at least one processor for controlling the optical sensor and processing the signal detected from the optical sensor to determine status information of the external object, And a convex lens protruding toward the sensor.

The optical sensor device according to various embodiments of the present disclosure is characterized in that a convex lens disposed on a surface facing the optical sensor of the transparent window changes the path of reflected light reflected from the surface of the transparent window to minimize the reduction of the effective optical signal, It is possible to have a reducing effect. In addition, the optical sensor device according to various embodiments of the present disclosure can provide an optimum specification of the components so that noise can be reduced even if tolerance occurs during assembly.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a structural diagram for explaining the configuration of an optical sensor device according to various embodiments of the present disclosure; Fig.
2A is a rear perspective view of an electronic device with an optical sensor device according to various embodiments of the present disclosure;
Figure 2B is a rear perspective view of a wearable device with an optical sensor device according to various embodiments of the present disclosure.
3A is an exploded perspective view of an optical sensor device according to various embodiments of the present disclosure as viewed from the front.
3B is an exploded perspective view of an optical sensor device according to various embodiments of the present disclosure, as viewed from the rear.
4 is a cross-sectional view of an optical sensor device according to various embodiments of the present disclosure;
5 is a cross-sectional view of an optical sensor device including a convex lens according to various embodiments of the present disclosure;
6A is a graph showing the amount of light of the PPG signal received by the photodetector according to the structure and thickness of the transparent window.
6B is a graph showing the ratio of the amount of light of the PPG signal according to another structure to that of the transparent window according to the thickness of the transparent window.
6C is a graph showing the amount of noise light received by the photodetector according to the structure and thickness of the transparent window.
6B is a graph showing the ratio of the amount of noise light according to another structure to the plane transparent window according to the thickness of the transparent window.
7 is a graph showing changes in the noise ratio according to the curvature and y-shift amount of a convex lens according to various embodiments of the present disclosure.
8 is a graph showing the amount of noise light according to the amount of protrusion of the convex lens according to the radius of curvature of the transparent window according to various embodiments of the present disclosure.
Figures 9A-9G illustrate an embodiment of various optical structures of the optical sensor device of the present disclosure.

Hereinafter, various embodiments of the present disclosure will be described with reference to the accompanying drawings. It should be understood, however, that this disclosure is not intended to limit the present disclosure to the particular embodiments, but includes various modifications, equivalents, and / or alternatives of the embodiments of the present disclosure. In connection with the description of the drawings, like reference numerals may be used for similar components.

In this document, the expressions "having," " having, "" comprising," or &Quot;, and does not exclude the presence of additional features.

In this document, the expressions "A or B," "at least one of A or / and B," or "one or more of A and / or B," etc. may include all possible combinations of the listed items . For example, "A or B," "at least one of A and B," or "at least one of A or B" includes (1) at least one A, (2) at least one B, (3) at least one A and at least one B all together.

The terms "first," "second," "first," or "second," etc. used in various embodiments may describe various components in any order and / or importance, Lt; / RTI > The representations may be used to distinguish one component from another. For example, the first user equipment and the second user equipment may represent different user equipment, regardless of order or importance. For example, without departing from the scope of the present disclosure, the first component may be referred to as a second component, and similarly, the second component may be named as the first component.

It is also possible that a component (eg, a first component) is "(operatively or communicatively coupled) / to" another component (eg, a second component) It is to be understood that when an element is referred to as being "connected to ", it is to be understood that the element may be directly connected to the other element or may be connected through another element (e.g., a third element). On the other hand, when it is mentioned that a component (e.g., a first component) is "directly connected" or "directly connected" to another component (e.g., a second component) It can be understood that there is no other component (e.g., a third component) between other components.

As used herein, the phrase " configured to " (or set) to be "configured" in accordance with the context may include, for example, " having for capacity to, To be designed to, "" adapted to, "" made to, "or" capable of ". The term " configured to (or configured) "may not necessarily mean specifically designed to be" specifically designed. "Instead, in some circumstances, the expression" a device configured to " (Or set) to perform the phrases A, B, and C. For example, a central processing unit " configured to perform the phrases A, B, and C " Purpose processor (e.g., a CPU or an application processor) that can perform one or more software programs stored on a dedicated central processing unit (e.g., an embedded central processing unit) ). ≪ / RTI >

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the other embodiments. The singular expressions may include plural expressions unless the context clearly dictates otherwise. All terms used herein, including technical or scientific terms, may have the same meaning as commonly understood by one of ordinary skill in the art of the present disclosure. Commonly used predefined terms may be interpreted to have the same or similar meaning as the contextual meanings of the related art and are not to be construed as ideal or overly formal in meaning unless expressly defined in this document . In some cases, the terms defined herein may not be construed to exclude embodiments of the present disclosure.

An electronic device according to various embodiments of the present disclosure may be, for example, a smartphone, a tablet personal computer, a mobile phone, a videophone, an e-book reader, A desktop personal computer, a laptop personal computer, a netbook computer, a workstation, a server, a personal digital assistant (PDA), a portable multimedia player (PMP) A medical device, a camera, or a wearable device (e.g., a smart watch, a smart glass), an electronic garment, an electronic bracelet, an electronic necklace, an electronic app apparel, an electronic tattoo, (e.g., a smart watch).

In some embodiments, the electronic device may be a smart home appliance. Smart home appliances include, for example, televisions, digital video disk players, audio, refrigerators, air conditioners, vacuum cleaners, ovens, microwaves, washing machines, air cleaners, set- such as home automation control panel, security control panel, TV box, such as Samsung HomeSync, Apple TV ^TM or Google TV ^TM , game consoles such as Xbox, PlayStation, , A camcorder, or an electronic frame.

In an alternative embodiment, the electronic device may be any of a variety of medical devices (e.g., various portable medical measurement devices such as a blood glucose meter, a heart rate meter, a blood pressure meter, or a body temperature meter), magnetic resonance angiography (MRA) A global positioning system receiver, an event data recorder (EDR), a flight data recorder (FDR), an automotive infotainment device, a navigation system, a navigation system, Electronic devices (eg marine navigation devices, gyro compass, etc.), avionics, security devices, head units for vehicles, industrial or home robots, ATMs (automatic teller's machines) point of sale or internet of things such as light bulbs, various sensors, electric or gas meters, sprinkler devices, fire alarms, thermostats, street lights, toasters, A water tank, a heater, a boiler, and the like).

According to some embodiments, the electronic device is a piece of furniture or a part of a building / structure, an electronic board, an electronic signature receiving device, a projector, Water, electricity, gas, or radio wave measuring instruments, etc.). In various embodiments, the electronic device may be a combination of one or more of the various devices described above. An electronic device according to some embodiments may be a flexible electronic device. Further, the electronic device according to the embodiment of the present disclosure is not limited to the above-described devices, and may include a new electronic device according to technological advancement.

Hereinafter, various embodiments will be described in detail with reference to the accompanying drawings. In describing the present invention with reference to the accompanying drawings, the same components are denoted by the same reference numerals regardless of the reference numerals, and a redundant description thereof may be omitted. In addition, for convenience of explanation, components may be exaggerated or reduced in size. For example, the size and thickness of each component shown in the drawings are arbitrarily shown for convenience of explanation, and thus the present invention is not necessarily limited to those shown in the drawings.

In addition, a Cartesian coordinate system is used, where the x axis direction refers to the longitudinal direction (e.g., longitudinal direction) of the electronic device and the y axis refers to the lateral direction (e.g., the width direction with a shorter length than the longitudinal direction) , and the z axis may denote the thickness direction of the electronic device. However, the x-axis, the y-axis, and the z-axis are not limited to three axes on the orthogonal coordinate system, and can be interpreted in a broad sense including the three axes. For example, the x-axis, y-axis, and z-axis may be orthogonal to each other, but may refer to different directions that are not orthogonal to each other.

1 is a view for explaining a configuration of an optical sensor device according to various embodiments of the present disclosure.

Referring to FIG. 1, an optical sensor device 100 (for example, a biometric information measuring device) according to an embodiment measures biological signals from a user's body, and estimates the user's biometric information based on the measured biometric signals. can do. For example, the optical sensor device 100 may measure biological signals at a part of the user's wrist or the like, and may estimate the cardiovascular information of the user based on the measured biological signals. Cardiovascular information may include arterial stiffness, blood pressure, arterial age, heart rate, oxygen saturation, and the like. According to one embodiment, the optical sensor device 100 sensor may be implemented in the form of a wearable deice that the user wears or may be provided in a portable electronic device.

According to various embodiments, the optical sensor device 100 may include an optical sensor 110, a signal processor 120, a controller 130, and a communication interface 140. According to one embodiment, the operation of signal processor 120 and controller 130 (e.g., at least one processor) may be operated by one or more processors executing instructions stored in memory.

According to various embodiments, the optical sensor 110 may include a light source 111 and a photodetector 112. The light source 111 can radiate an optical signal modulated according to a specific frequency to a human body, and the photodetector 112 can receive reflected light reflected from a human body and convert the received reflected light into an electrical signal. An electrical signal obtained through reflected light may be referred to as a "PPG signal ". The PPG can be determined by analyzing the intensity change of the reflected light. The light source 111 may include, for example, an electric light source such as a light emitting diode (LED) and a laser diode, or a chemical light source such as a fluorescent lamp. The wavelength of the light emitted from the light source 111 can be variously determined based on the depth for penetrating the skin, the power efficiency, and the like. The photodetector 112 may include, for example, a photodiode or a phototransistor.

According to various embodiments, the signal processor 120 may perform signal processing on an electrical signal provided from the photodetector 112. The signal processor 120 may include a preprocessor 121, an amplifier 122 and an analog-to-digital converter (ADC) 123.

According to various embodiments, the preprocessor 121 converts the components of the electrical signal detected by the photodetector 112, for example, the PPG signal, from a current signal to a voltage signal, and filters the converted voltage signal to remove noise Or to obtain the required signal area. The amplifier 122 may amplify the signal transmitted from the preprocessor 121 and the ADC 123 may convert the signal amplified by the amplifier 122 into a digital signal.

According to various embodiments, the controller 130 may measure the waveform based on the digital signal provided from the signal processor 120. The controller 130 extracts feature points (e.g., peak points, valley points, maximum points of tilt, minimum points of tilt, etc.) of waveforms, and generates biometric information, For example, PPG can be measured.

According to various embodiments, the communication interface unit 140 may transmit data to an external device (e.g., a mobile device, a personal computer, or a network) using wireless communication such as Bluetooth, Zigbee, Or receive commands or data from an external device.

According to various embodiments, the optical sensor device 100 may further include a user interface (UI). The optical sensor device 100 may receive various inputs or provide measured biometric information through a user interface unit. For example, the optical sensor device 100 includes a touch display, through which the user's information can be input or the measured biometric information can be displayed.

2A is a rear perspective view of an electronic device with an optical sensor device according to various embodiments of the present disclosure; The optical sensor device 210 of FIG. 2A may at least partially resemble the optical sensor device 100 shown in FIG. 1, or may include other embodiments of the optical sensor device.

2A, the electronic device 220 may include an optical sensor device 210 disposed on one side (e.g., the backside 221) of the electronic device 220. [ According to one embodiment, the optical sensor device 210 may be installed in such a manner that a part of the external appearance of the electronic device 220 is exposed, and may contact a part of the user's body to measure biometric information. For example, the optical sensor device 210 may be exposed through an opening included in the outer housing of the electronic device 220. The optical sensor device 210 can be disposed at a position where a part (e.g., a finger) of the user's body can be contacted in the most comfortable state when the user holds the electronic device 220. [ According to one embodiment, the optical sensor device 210 may include other electronic components (e.g., camera device 222 and / or fingerprint sensor 223) disposed on the back surface 221 of the electronic device 220 Can be disposed adjacent to each other. According to one embodiment, the electronic device 220 may include a touch display disposed in at least a portion of an area of the other surface (e.g., the front), and the touch display may function as a user interface of the electronic device 220 .

Figure 2B is a rear perspective view of a wearable device with an optical sensor device according to various embodiments of the present disclosure. The optical sensor device 210 of FIG. 2B may include at least some of the optical sensor device 100 shown in FIG. 1 or the optical sensor device 210 shown in FIG. have.

2B, the wearable electronic device 230 may include an optical sensor device 210 disposed on one side (e.g., the rear surface 231) of the wearable device 230. [ According to one embodiment, the wearable device 230 may include a strap 232 that is configured to be worn on the wearer's wrist. The optical sensor device 210 can measure the biometric information by contacting the user's wrist when the wearer wears the wearable device 230 using the strap 232. According to one embodiment, the wearable electronic device 220 may include a touch display disposed in at least a portion of an area on another side (e.g., a front side), and the touch display may function as a user interface of the electronic device 220 have. In another embodiment, the optical sensor device 210 may be disposed on the inside of the strap 232 (e.g., the side that contacts the user's body).

3A is an exploded perspective view of an optical sensor device according to various embodiments of the present disclosure as viewed from the front. 3B is an exploded perspective view of an optical sensor device according to various embodiments of the present disclosure, as viewed from the rear. The optical sensor device 300 of Figures 3a and 3b may be at least partially similar to the optical sensor device 100 shown in Figure 1 or the optical sensor device 210 shown in Figures 2a and 2b, Examples may be included.

3A, the optical sensor device 300 includes an optical sensor 310 including a light source 311 and a photodetector 312, a transparent window 320 disposed to overlap the optical sensor 310, A sensor housing 330 (e.g., a bracket or decorative member) for supporting the sensor 320.

According to various embodiments, the transparent window 320 may be disposed in a direction facing the light source 311 of the optical sensor 310 and the optical detector 312. The light emitted from the light source 311 may be transmitted to the surface of the user's body that is in contact with the outer surface of the transparent window 320 through the transparent window 320. The light transmitted to the surface of the user's body may be reflected from the skin and the blood vessel, and may be transmitted through the transparent window 320 and incident on the photodetector 312. Accordingly, at least a portion of the transparent window 320 where the body surface of the user is in contact may have various structures and shapes that are exposed to the outside of the electronic device. According to one embodiment, the transparent window 320 may be formed of a material selected from the group consisting of a silicon (Si) -based ceramic, a glass, a polymer-based plastic, Or a rubber resin, for example. According to one embodiment, the transparent window 320 may include a non-transparent portion 322 (e.g., a non-transparent coating layer) to provide a suitable optical path of the light and / . ≪ / RTI > For example, the transparent window 320 corresponds to the first transmissive portion 321a and the photodetector 312 formed vertically (z-axis) at the corresponding positions on the upper surface of the light source 311 of the optical sensor 310 And a second transmitting portion 321b formed at a position where the second transmitting portion 321b is formed. In other words, the transparent window 320 may include a non-transmissive portion 322 in an area other than the first and second transmissive portions 321a and 321b. The non-transmissive portion 322 may be formed as a black print layer on the top and / or backside of the transparent window 320.

According to various embodiments, the transparent window 320 may extend through an opening included in the outer housing (e.g., a case, frame, etc.) of the electronic device in which the optical sensor device 300 or the optical sensor device 300 is mounted, Can be exposed to the outside. The transparent window 320 may include a sensor housing 330 for rigid support in exposing as an exterior of the electronic device. According to one embodiment, the sensor housing 330 may be integrally formed with the outer housing of the electronic device, or may be formed separately. According to one embodiment, the sensor housing 330 may be used as a decorative member for the appearance of the electronic device, or may further include a decorative member. According to various embodiments, the sensor housing 330 includes a tubular protrusion 332 having an opening 333 through which at least a portion of the transparent window 320 can be exposed and formed along the rim of the opening 333 . The opening 333 may have a size such that the area where the light source 311 of the optical sensor 310 and the area of the optical detector 312 are overlapped when viewed from above. The sensor housing 330 may include a rim 331 (or flange) formed along the periphery of the protrusion 332. The rim portion 331 is formed in a shape that can be fixedly coupled to an outer housing of an electronic device (for example, the electronic device 220 in Fig. 2A or the wearable device 230 in Fig. 2B) to which the optical sensor device 300 is mounted . When the optical sensor device 300 is mounted on the electronic device, the rim portion 331 is coupled to the inside of the outer housing such that at least a part of the protrusion is exposed or protruded through an opening included in the outer housing of the electronic device. can do. Since the protrusion 332 of the sensor housing 330 is exposed as an outer appearance to the electronic device, the sensor housing 330 can have a beautiful appearance or can be formed of various materials such as metal or plated synthetic resin material.

3B, a transparent window 320 according to one embodiment of the present disclosure may include an optical system including a light source (e.g., light source 311 in FIG. 3A) and a light detector (e.g., optical detector 312 in FIG. 3A) And a convex lens 323 disposed on a surface facing the sensor 310. [ The convex lens 323 can reduce the amount of noise light by changing the optical path of the light emitted from the light source 311 and the reflected light received by the optical detector 312. [ The function of the convex lens 323 and specific specifications such as the curvature and the protrusion amount will be described later.

According to various embodiments, each component of the optical sensor device 300 can be separately assembled or modularized into a single component. For example, the optical sensor device 300 is mounted on a circuit board (e.g., PCB, FPCB, etc.) where the optical sensor 310 is located within the electronics device, and a transparent window 320 is provided through the opening of the outer housing And can be mounted on the electronic device in such a manner as to be fixedly coupled to be exposed. Alternatively, for example, the transparent window 320 may be mounted to the sensor housing 330 and the sensor housing 330 may be mounted to the electronic device in such a manner that the sensor housing 330 is fixedly coupled to the outer housing of the electronic device. Alternatively, for example, the optical sensor 310 and the transparent window 320 and / or the sensor housing 330 can be used in such a way that they are produced in one module and fixedly coupled to the electronic device or detached as an external device have.

4A is a cross-sectional view of an optical sensor device according to various embodiments of the present disclosure; The optical sensor device 400 shown in Fig. 4 may be applied to the optical sensor device 100 shown in Fig. 1, the optical sensor device 210 shown in Figs. 2A and 2B, or the optical sensor device 300 shown in Fig. Or may include other embodiments of the optical sensor device.

4, the optical sensor device 400 includes a light source 411 and a photodetector 412 which are disposed in proximity to or in close proximity to the optical sensor 410 and the optical sensor 410, And may include a transparent window to be disposed. The light emitted from the light source 411 of the optical sensor 410 may be transmitted through the transparent window 420 and transmitted to the user's body surface, for example, the finger 430. The transmitted light can be reflected from the skin and the blood vessel of the finger 430 and the reflected light can be transmitted through the transparent window 420 and incident on the photodetector 412. The transparent window 420 may have a high reflectance at the surface depending on the material and shape. The light emitted from the light source due to the reflectance can not be transmitted through the transparent window 420, but may be reflected by the inner surface of the transparent window 420 and received by the photodetector 412 to be noise. Noise can be generated by reflection at the boundary of the transparent window 420 when it comes into contact with a material having a different refractive index from the refractive index of the transparent window 420, for example, air. In other words, the noise may be caused by a Fresnel-loss (or return-loss) occurring at the surface of the transparent window 420. Generally, the greater the difference in the refractive index and / or the reflectance, the larger the noise can be generated in the Fresnel lens.

4A, an optical sensor device 400 according to various embodiments of the present disclosure includes an optical sensor 410 including a light source 411 and a photodetector 412, But may include a transparent window 420 in which a convex lens 423 is positioned on a surface facing the optical sensor 410.

According to various embodiments of the present disclosure, the optical sensor device 400 may include a convex lens 423 disposed in the transparent window 420 for reduction of the noise described above. The convex lens 423 may be integrally formed with the transparent window or may be attached to the back surface 422 of the window as a discrete component. According to one embodiment, the convex lens 423 may include a light source 411 and a light detector 412 ) Of the transparent window (420). The convex lens 423 can reduce the reflected area S of the light reaching the image surface 421 of the transparent window 420 by changing the optical path of the noise by the light converging effect. The optical path change of the convex lens 423 can reduce the overall amount of reflected light returning to the photodetector 412, thereby reducing the noise.

Generally, a structure for reducing noise in an optical sensor device includes a method in which a black block type barrier film structure is further included between optical paths of noise. However, the accuracy of the optical sensor device can be reduced by influencing the effective reflection amount to be actually measured. A comparison of the structure-specific PPG signal and noise amount in a transparent window to which various structures such as a transparent window according to various embodiments of the present disclosure are applied is as illustrated in Table 1 below.

division PPG signal light quantity Noise intensity Planar transparent window 100% 100% Transparent windows containing barrier wall structures 29.4% 26.7% Transparent window containing convex lens 95.3% 47.0%

[Comparison of PPG signal and noise intensity by structure]

5 is a cross-sectional view of an optical sensor device including a convex lens according to various embodiments of the present disclosure; The optical sensor device 500 shown in Fig. 5 is similar to the optical sensor device 100 shown in Fig. 1, the optical sensor device 210 shown in Figs. 2A and 2B, the optical sensor device 300 shown in Fig. 3A, At least partially similar to the optical sensor device 400 shown in FIG. 4, or may include other embodiments of the optical sensor device.

5, an optical sensor device 500 according to various embodiments of the present disclosure includes an optical sensor 510 including a light source 511 and a light detector 512, And may include a transparent window 520 including a convex lens 523 located on a lower surface 522 facing the optical sensor 510.

The specifications of the components included in the optical sensor device 500 in various embodiments of the present disclosure can be variously determined based on noise reduction efficiency and various product design environments and the like. For example, the specifications of these components may vary depending on the thickness T of the transparent window 520, the radius of curvature R of the convex lens 523, the center C _L of the convex lens 523, The maximum protruding length P of the protruding convex lens 523 or the interval B between the transparent window 520 and the optical sensor 510 may be included.

Experiments to determine the specifications of the most ideal components for reducing noise in the optical sensor device 500 will now be described in terms of the following: i) the center C _S of the light source 511 and the center C _D of the optical detector 512 Ii) the distance B between the transparent window 520 and the optical sensor 510 is 0.4 mm (e.g., between the center C _S of the light source 511 and the light detector 511) 512) (C _D )) as the reference (controlled variable). The shorter the interval (B), the smaller the amount of noise generated. However, the tolerance (÷ 0.2 mm) that can occur during assembly is considered to be 0.4 mm. The center of curvature C _L of the convex lens 523 was experimented based on the case where the center C _s of the light source 511 and the center C _D of the photodetector 512 were located.

Further, with respect to the thickness T of the transparent window, generally, the noise tends to increase together with the increase of the thickness T of the transparent window. Therefore, the thinner the thickness of the transparent window 520, the more advantageous it is in terms of noise reduction. However, the thickness (T) of the transparent window is not limited to a thickness of 1 mm or more due to restrictions such as being installed to be exposed to the outside, or having a rigidity higher than a certain strength, . ≪ / RTI >

FIG. 6A is a graph showing the amount of light of the PPG signal received by the photodetector according to the structure and thickness of the transparent window, FIG. 6B is a graph showing the ratio of the amount of light of the PPG signal according to another structure, Graph. 6C is a graph showing the amount of noise received by the photodetector according to the structure and thickness of the transparent window, FIG. 6D is a graph showing the ratio of the amount of noise light according to another structure, to be.

6A-6D, the structure of a transparent window (e.g., transparent window 520 of FIG. 5) including a convex lens 523 in various embodiments of the present disclosure, Compared with the window structure, it is confirmed that the light amount of the effective PPG signal is received at a ratio of approximately 80% or more, and the noise light amount is received at a ratio of approximately 60% or less. Also, it can be seen that although the window structure including the barrier rib structure receives a noise light amount at a lower rate than the transparent window 520 including the convex lens 523, the light amount of a valid PPG signal is also received at 50% or less have. That is, the structure of the transparent window 520 including the convex lens (e.g., the convex lens 523 in FIG. 5) according to various embodiments of the present disclosure, as compared to the transparent window including the barrier rib structure, And thus can have high accuracy in the measurement of biometric information. In other words, the optical sensor device 500 having the transparent window 520 including the convex lens 523 is advantageous in performance in comparison with the device having the transparent window including the barrier rib structure.

Referring to Figures 6A and 6B, an appropriate value of the thickness T of (e.g., the transparent window 520 of Figure 5) may be determined. Referring to FIG. 6A, it can be seen that the light amount of the effective PPG signal sharply decreases when the thickness T of the transparent window 520 becomes thicker than approximately 2.4 mm. 6B, when the thickness T of the transparent window 520 exceeds 2.0 mm, the ratio of the effective amount of the PPG signal to the conventional planar transparent window decreases. Thus, the thickness T of the transparent window 520 according to various embodiments of the present disclosure may be designed to have a value preferably less than or equal to 2.0 mm. Alternatively, the thickness T of the transparent window 520 may be designed to be 5/8 times or less the length between the light source 511 and each center of the photodetector 512.

7 is a graph showing changes in the noise ratio according to the curvature and y-shift amount of a convex lens according to various embodiments of the present disclosure.

The smaller the value of the radius of curvature R of the transparent window (e.g., the transparent window 520 of FIG. 5) according to various embodiments of the present disclosure, the greater the refraction effect, and the greater the refraction effect. However, in the case of the conventional planar transparent window, there is no change in noise even when moving in the left and right (longitudinal direction or y direction in FIG. 5) with respect to the optical sensor. However, the convex lens (e.g., the convex lens 523 in FIG. , The center C _L of the convex lens is changed and the light path is changed and a change in noise may occur due to the movement of the transparent window 520. In order to take this into consideration, it is assumed that the center of the convex lens C _L is centered between a light source (e.g., the light source 511 in FIG. 5) and a photodetector (e.g., the photodetector 512 in FIG. 5) Experimental results of varying the magnitude of the noise while varying the magnitude of the radius of curvature (R) are as shown in Table 2 and FIG. 7 below. (In the experiment, the thickness T of the transparent window was 1.5 mm, and the distance B between the optical sensor 510 and the transparent window 520 was 0.4 mm.

Change (mm) Plane (R = 0) R = 1.0 R = 2.0 R = 4.5 R = 5.0 R = 6.0 R = 7.0 -0.20 100.0% 117.6% 72.5% 46.3% 33.5% 41.2% 47.3% -0.15 100.0% 84.2% 48.6% 34.1% 37.7% 45.2% 50.7% -0.1 100.0% 50.6% 29.9% 37.6 42.2% 49.4% 54.8% -0.05 100.0% 44.2% 22.8% 43.3% 47.2% 53.8% 59.0% 0.00 100.0% 29.6% 20.3% 48.9% 52.6% 59.1% 63.2% 0.05 100.0% 23.6% 25.8% 55.3% 58.3% 63.7% 68.0% 0.10 100.0% 22.6% 34.9% 62.4% 64.8% 70.5% 73.6% 0.15 100.0% 42.8% 47.5% 70.3% 72.3% 76.0% 78.8% 0.20 100.0% 81.2% 65.9% 79.1% 79.8% 82.7% 83.8%

[Noise comparison at the center position change (y-shift) according to the size of the radius of curvature (R)] [

Referring to Table 2 and 7, the positive lens 523, the center (C _L), in this case located in the zero, the radius of curvature (R) is becomes smaller is large so that noise is reduced, the center of the convex lens (C _L of As a result, the effect of noise reduction is drastically reduced. For example, when the radius of curvature R is 1.0 mm, when the center C _L is moved by -0.20 mm, the amount of noise light is 117.6% as compared with the conventional plane transparent window, and the result is rather increased. In another case, for example, when the radius of curvature R is 7.0 mm, even when the center C _L moves by ± 0.2 mm, the characteristic of reducing the amount of noise light is secured as compared with the case where the convex lens 523 is not present at all positions . However, considering the assembly tolerance ± 0.2 mm that can occur during assembly, it has an improved noise reduction effect over the entire range, especially when the center (CL) of the convex lens is at 0, the radius of curvature R ) Is approximately 2.0 mm, it is possible to obtain an optimum effect and reliability. 2.0 mm is 4/3 times the thickness of the transparent window (T, 1.5 mm). In addition, when the radius of curvature R is approximately 4.5 mm, it can be confirmed that the noise reduction effect is 20% or more in the entire range. 4.5 mm is three times the thickness of the transparent window (T, 1.5 mm). That is, in the optical sensor device according to the embodiment of the present disclosure, when the radius of curvature R of the convex lens is approximately 4/3 to 3 times the thickness T of the transparent window, the noise reduction effect and the product reliability . ≪ / RTI > Particularly, when the radius of curvature R of the convex lens is 4/3 times the thickness T of the transparent window, it is possible to obtain the highest efficiency in noise reduction and product reliability.

8 is a graph showing the amount of noise light according to the amount of protrusion of the convex lens according to the radius of curvature of the transparent window according to various embodiments of the present disclosure. Table 3 below is a table showing the width of the convex lenses according to the amount of protrusion (independent variable).

division Convex lens width length The radius of curvature (R) 1.0 2.0 3.0 The amount of protrusion (A) 0.00 0.00 0.00 0.00 0.05 0.62 0.89 1.09 0.10 0.87 1.25 1.54 0.15 1.05 1.52 1.87 0.20 1.20 1.74 2.15 0.25 1.32 1.94 2.40 0.30 1.43 2.11 2.62 0.35 1.52 2.26 2.81

[Length of convex lens width according to projected amount (p)] [

First, referring to FIG. 8, the noise change according to the protrusion amount p of the convex lens is continuously decreased until the length of the protrusion amount p is 0.35 mm when the radius of curvature R is 1.0 mm, When the radius of curvature R is 2.0 mm, the length of the protrusion p decreases to 0.3 mm, but when the radius of curvature R is 3.0 mm, the length of the protrusion p decreases to 0.15 mm, , Respectively.

Based on the above results, when the protrusion amount p is an independent variable, the width of the convex lens is set as a dependent variable, and the value of the width is shown in Table 3 above. When the width of the convex lens is approximately 0 to 2.0 mm, the reduction amount of the noise is gradually increased as the width of the convex lens becomes larger, and when the width of the convex lens is 2.0 mm The noise reduction tendency is reduced again. The width of the convex lens 523 according to the embodiment is about 2 mm when the distance d between the center of the light source 511 and the center of the photodetector 512 is 3.2 mm The highest noise reduction effect can be obtained. In other words, when the width of the convex lens 523 is approximately 5/8 times the distance between the center of the light source 511 and the center of the photodetector 512, the highest noise reduction effect can be obtained.

Figures 9A-9G illustrate various embodiments of various optical structures of the optical sensor device of the present disclosure. The optical sensor devices 900a, 900b, 900c, 900d, 900e, 900f, and 900g shown in Figs. 9A to 9G include the optical sensor device 100 shown in Fig. 1, the optical sensor device 100 shown in Figs. 2A and 2B, The optical sensor device 300 shown in FIG. 3A, the optical sensor device 400 shown in FIG. 4, or the optical sensor device 500 shown in FIG. 5, Embodiments may be included.

9A to 9G, each of the optical sensor devices 900a, 900b, 900c, 900d, 900e, 900f, 900g includes a light source 921 and a photodetector 922 disposed adjacent to the light source 921. [ And a transparent window 910 disposed at a position overlapping with the optical sensor 920. The optical sensor 920 may include a transparent window 910, According to one embodiment, the transparent window 910 may be formed in various shapes as described below, in various shapes of the convex lenses 910a, 910b, 910c, 910d, 910e, 910f, and 910g.

9A, a transparent window 910 according to one embodiment of the present disclosure may further include a convex lens 910a disposed on a surface facing the optical sensor 920. [ The convex lens 910a can be positioned substantially at the center between the light source 921 and the photodetector 922 with a substantially circular shape when viewed from above. 9B, a transparent window 910 according to one embodiment of the present disclosure may further include a cylindrical convex lens 910b disposed on a surface facing the optical sensor 920. [ The cylindrical convex lens 910b may be disposed in a direction that crosses the light source 921 and the photodetector 922 at approximately the center between the light source 921 and the photodetector 922 when viewed from above.

9C, the transparent window 910 according to one embodiment of the present disclosure may further include an elliptical convex lens 910c disposed on a surface facing the optical sensor 920. [ The elliptical convex lens 910c, when viewed from above, can be disposed at a substantially central position between the light source 921 and the photodetector 922 with a substantially elliptical shape. 9D, a transparent window 910 according to one embodiment of the present disclosure may further include a cylindrical convex lens 910d disposed on a surface facing the optical sensor 920. [ The cylindrical convex lens 910d may have a shape in which the curvature between both ends is gentle or flat than the curvature of both ends toward the light source 921 and the photodetector 922 when viewed from the side. The cylindrical convex lens 910d may be disposed in a direction across the light source 921 and the photodetector 922 at approximately the center between the light source 921 and the photodetector 922 when viewed from above. The cylindrical convex lenses 910c and 910d can be applied when the distance between the light source 921 and the optical detector 922 is long.

9E, a transparent window 910 according to one embodiment of the present disclosure further includes a convex lens 910e disposed on the opposite surface (the surface exposed to the exterior) of the surface facing the optical sensor 920 . The convex lens 910e can be positioned substantially at the center between the light source 921 and the photodetector 922 with a substantially circular shape when viewed from above. 9F, the transparent window 910 according to one embodiment of the present disclosure may further include a cylindrical convex lens 910f disposed on the opposite side of the surface facing the optical sensor 920. [ The cylindrical convex lens 910f may be disposed in a direction crossing the light source 921 and the photodetector 922 at approximately the center between the light source 921 and the photodetector 922 when viewed from above. The optical sensor device according to one embodiment can have the effect of reducing noise by placing a convex lens 910e or 910f on the outer surface of the transparent window 910 and changing the optical path of reflected light.

9G, a first convex lens 910g and a second convex lens 911g may be further disposed on both sides of the transparent window 910 according to an embodiment of the present disclosure. The first and second convex lenses 910g and 911g may be positioned substantially at the center between the light source 921 and the photodetector 922 as viewed from above. Each of the first and second convex lenses 910g and 911g has an appropriate curvature and shape so that the optical path of the reflected light can be changed to provide an effect of reducing noise in the optical sensor device.

An optical sensor device according to an embodiment of the present disclosure includes: a transparent window including a first surface facing the outside of the optical sensor device and a second surface facing the first surface; And an optical sensor that includes a light source that emits light toward the transparent window and a light detector that receives light through the transparent window and is spaced apart from the second surface of the transparent window by a predetermined distance, And a convex lens protruding from the at least part of the second surface toward the optical sensor.

According to one embodiment of the present disclosure, the convex lens may be disposed between the light source and the photodetector when the first surface is viewed from above.

According to one embodiment of the present disclosure, the convex lens can be disposed at the center of the distance between the centers of the light source and the photodetector when the first surface is viewed from above.

According to an embodiment of the present disclosure, the radius of curvature of the convex lens may be 4/3 to 3 times the thickness of the transparent window.

According to one embodiment of the present disclosure, the convex lens is formed such that when the first surface is viewed from above, the width of the convex lens is approximately 5/8 times the length between the centers of the light source and the photodetector .

According to one embodiment of the present disclosure, the thickness of the transparent window may be no more than 5/8 times the length between the centers of the light source and the photodetector.

According to one embodiment of the present disclosure, the constant spacing may be less than about 1/8 times the length between the centers of the light source and the photodetector.

According to one embodiment of the present disclosure, the convex lens has a cylindrical shape and may be arranged to traverse the light source and the photodetector when the first surface is viewed from above.

According to an embodiment of the present disclosure, the convex lens may have an elliptical shape.

According to an embodiment of the present disclosure, the transparent window may further include a second convex lens disposed on the opposite side of the surface on which the convex lens is disposed.

An electronic device according to one embodiment of the present disclosure includes: a transparent window including a first surface facing outwardly of the electronic device and a second surface facing the first surface and being fixedly coupled to an outer housing of the electronic device; A light source for emitting light toward the transparent window and a photodetector for receiving light reflected from an external object in contact with the first surface of the transparent window, An optical sensor disposed on an internal circuit board of the electronic device; And at least one processor for controlling the optical sensor and processing the signal detected from the optical sensor to determine status information of the external object, And a convex lens protruding toward the sensor.

According to one embodiment of the present disclosure, the convex lens may be disposed between the light source and the photodetector when the first surface is viewed from above.

According to one embodiment of the present disclosure, the convex lens may be disposed at the center of the distance between the centers of the light source and the photodetector when the first surface is viewed from above.

According to an embodiment of the present disclosure, the convex lens may have a radius of curvature of 4/3 to 3 times the thickness of the transparent window.

According to one embodiment of the present disclosure, when the convex lens is viewed from above, the convex lens is projected so that the width of the convex lens is approximately 5/8 times the length between the centers of the light source and the photodetector .

According to one embodiment of the present disclosure, the thickness of the transparent window may be no more than 5/8 times the length between the centers of the light source and the photodetector.

According to one embodiment of the present disclosure, the constant spacing may be less than about 1/8 times the length between the centers of the light source and the photodetector.

According to one embodiment of the present disclosure, the convex lens has a cylindrical shape and may be arranged to traverse the light source and the photodetector when the first surface is viewed from above.

According to an embodiment of the present disclosure, at least a part of the transparent window may be exposed to the outside through the opening of the outer housing.

According to an embodiment of the present disclosure, the sensor housing may further include a tubular sensor housing protruding outward from an edge of the opening included in the outer housing.

The term "module" as used herein encompasses units comprised of hardware, software or firmware and may be used interchangeably with terms such as, for example, logic, logic blocks, components, or circuits. A "module" may be an integrally constructed component or a minimum unit or part thereof that performs one or more functions. "Module" may be implemented either mechanically or electronically and may include, for example, known or later developed, application-specific integrated circuit (ASIC) chips, field-programmable gate arrays (FPGAs) Logic devices. At least some of the devices (e.g., modules or functions thereof) or methods (e.g., operations) according to various embodiments may be implemented with instructions stored in a computer-readable storage medium (e.g., memory) . When the instruction is executed by the processor, the processor may perform a function corresponding to the instruction. The computer-readable recording medium may be a hard disk, a floppy disk, a magnetic medium such as a magnetic tape, an optical recording medium such as a CD-ROM, a DVD, a magnetic-optical medium such as a floppy disk, The instructions may include code that is generated by the compiler or code that may be executed by the interpreter. Modules or program modules according to various embodiments may include at least one or more of the components described above Operations that are performed by modules, program modules, or other components, in accordance with various embodiments, may be performed in a sequential, parallel, iterative, or heuristic manner, or at least in part Some operations may be executed in a different order, omitted, or other operations may be added.

The embodiments of the present invention disclosed in this specification and drawings are intended to be illustrative only and not for purposes of limitation of the scope of the present invention, I do not want to. Accordingly, the scope of various embodiments of the present invention should be construed as being included in the scope of various embodiments of the present invention in addition to the embodiments disclosed herein, all changes or modifications derived from the technical ideas of various embodiments of the present invention.

Claims (20)

In the optical sensor device,
A transparent window including a first surface facing the outside of the optical sensor device and a second surface facing the first surface; And
An optical sensor including a light source that emits light toward the transparent window and a light detector that receives light through the transparent window, the optical sensor being spaced apart from the second surface of the transparent window,
Wherein the transparent window comprises a convex lens projecting toward the optical sensor in at least a portion of the second surface.
The method according to claim 1,
Wherein the convex lens is disposed between the light source and the photodetector when the first surface is viewed from above.
The method according to claim 1,
Wherein the convex lens is disposed at the center of a distance between the respective centers of the light source and the photodetector when the first surface is viewed from above.
The method according to claim 1,
Wherein the radius of curvature of the convex lens is not less than 4/3 times and not more than 3 times the thickness of the transparent window.
The method according to claim 1,
Wherein the convex lens is protruded so that the width of the convex lens is approximately 5/8 times or less the length between the centers of the light source and the photodetector when the first surface is viewed from above.
The method according to claim 1,
Wherein the thickness of the transparent window is no more than 5/8 times the length between the centers of the light source and the photodetector.
The method according to claim 1,
Wherein the predetermined distance is about 1/8 times or less the length between the centers of the light source and the photodetector.
The method according to claim 1,
Wherein the convex lens has a cylindrical shape and is arranged to cross the space between the light source and the photodetector when the first surface is viewed from above.
The optical sensor device according to claim 1, wherein the convex lens has an elliptical shape.
The optical sensor device according to claim 1, wherein the transparent window further comprises a second convex lens disposed on the opposite side of the surface on which the convex lens is disposed.
In an electronic device,
A transparent window including a first surface facing the exterior of the electronic device and a second surface facing the first surface and being fixedly coupled to an outer housing of the electronic device;
A light source for emitting light toward the transparent window and a photodetector for receiving light reflected from an external object in contact with the first surface of the transparent window, An optical sensor disposed on an internal circuit board of the electronic device; And
At least one processor for controlling the optical sensor and for processing the signal detected from the optical sensor to determine status information of the external object,
Wherein the transparent window includes a convex lens projecting from the at least a portion of the second surface toward the optical sensor.
12. The method of claim 11,
Wherein the convex lens is disposed between the light source and the photodetector when the first surface is viewed from above.
12. The method of claim 11,
Wherein the convex lens is disposed at a center of a distance between the center of each of the light source and the photodetector when the first surface is viewed from above.
12. The method of claim 11,
And the radius of curvature of the convex lens is not less than 4/3 times and not more than 3 times the thickness of the transparent window.
12. The method of claim 11,
Wherein the convex lens is protruded so that the width of the convex lens is approximately 5/8 times the length between the centers of the light source and the photodetector when the first surface is viewed from above.
12. The method of claim 11,
Wherein the thickness of the transparent window is 5/8 times or less the length between the centers of the light source and the photodetector.
12. The method of claim 11,
Wherein the predetermined interval is approximately 1/8 times or less the length between the centers of the light source and the photodetector.
12. The method of claim 11,
Wherein the convex lens has a cylindrical shape and is disposed across the light source and the photodetector when the first surface is viewed from above.
12. The method of claim 11,
Wherein at least a part of the transparent window is exposed to the outside through an opening of the outer housing.
20. The method of claim 19,
Further comprising a sensor housing having a tubular shape protruding outward from an edge of the opening included in the outer housing.

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