Patent Description:
An electronic device such as a smartphone or a tablet personal computer may perform various functions such as a call function, an Internet search function, and a health care function. The electronic device may execute an application to provide a variety of information to a user.

Also, the electronic device may be equipped with various sensors to collect information of an ambient environment or information (e.g., biometric information) about the user. The electronic device may apply the collected information to the execution of an application. Nowadays, an electronic device that is equipped with an optical sensor for collecting biometric information (e.g., fingerprint information, heartbeat information, or iris information) of the user is being launched. <CIT> discloses an optical sensor device having an emitter, receiver and light conductor unit, the light conductor unit allowing a light beam emitted by the emitter to be coupled into a window, coupled out of the window and directed onto the receiver. <CIT> discloses an optical sensor device having a light transmitter, light receiver and lens plate, with which a beam of light emitted by the light transmitter is coupled into a window pane, coupled out of the window pane and directed onto the light receiver. <CIT> discloses an optical sensor device having a light emitter, light receiver, and a lens plate used for coupling a pencil of rays, radiated by the light emitter, into and out of a pane and directing it onto the light receiver.

An electronic device according to the related art includes an isolator between a light emitting unit and a light receiving unit when being equipped with an optical sensor for collecting biometric information of the user. The isolator may prevent a light emitted from the light emitting unit from being introduced to the light receiving unit without reflection by an external object. When the isolator is disposed, a mounting space of the optical sensor increases.

Also, when the light emitting unit generates non-directional photons, the output photons may be scattered without directivity, thereby causing a decrease in the amount of photons introduced to the light receiving unit. This means that the efficiency with which the sensor receives a light decreases.

The present disclosure has been made to address at least the disadvantages described above and to provide at least the advantages described below.

In accordance with an aspect of the present disclosure, an electronic device defined by the features of claim <NUM> is provided.

An electronic device according to various embodiments of the disclosure may be equipped with an optical sensor using a Fresnel lens without an isolator between a light emitting unit and a light receiving unit, thus improving a transfer efficiency of photons.

The electronic device according to various embodiments of the disclosure may be equipped with a Fresnel lens at a light receiving unit to total reflect and refract an incident light, thus improving a transfer efficiency of photons. Accordingly, the performance of object recognition may be improved.

The electronic device according to various embodiments of the disclosure may be equipped with a Fresnel lens at a light emitting unit to total reflect and refract a light generated from the light emitting unit, thus improving a transfer efficiency of photons.

The electronic device according to the invention includes a notch structure in a peripheral area of a Fresnel lens, thus preventing the crosstalk.

Hereinafter, various embodiments of the present disclosure will be described with reference to the accompanying drawings. Accordingly, those of ordinary skill in the art will recognize that modification, equivalent, and/or alternative on the various embodiments described herein can be variously made without departing from the scope of the present disclosure. With regard to description of drawings, similar components may be marked by similar reference numerals.

In the disclosure disclosed herein, the expressions "have", "may have", "include" and "comprise", or "may include" and "may comprise" used herein indicate existence of corresponding features (for example, elements such as numeric values, functions, operations, or components) but do not exclude presence of additional features.

In the disclosure disclosed herein, the expressions "A or B", "at least one of A or/and B", or "one or more of A or/and B", and the like used herein may include any and all combinations of one or more of the associated listed items. For example, the term "A or B", "at least one of A and B", or "at least one of A or B" may refer to all of the case (<NUM>) where at least one A is included, the case (<NUM>) where at least one B is included, or the case (<NUM>) where both of at least one A and at least one B are included.

The terms, such as "first", "second", and the like used herein may refer to various elements of various embodiments of the present disclosure, but do not limit the elements. For example, such terms are used only to distinguish an element from another element and do not limit the order and/or priority of the elements. For example, a first user device and a second user device may represent different user devices irrespective of sequence or importance. For example, without departing the scope of the present disclosure, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element.

It will be understood that when an element (for example, a first element) is referred to as being "(operatively or communicatively) coupled with/to" or "connected to" another element (for example, a second element), it can be directly coupled with/to or connected to the other element or an intervening element (for example, a third element) may be present. In contrast, when an element (for example, a first element) is referred to as being "directly coupled with/to" or "directly connected to" another element (for example, a second element), it should be understood that there are no intervening element (for example, a third element).

According to the situation, the expression "configured to" used herein may be used as, for example, the expression "suitable for", "having the capacity to", "designed to", "adapted to", "made to", or "capable of". The term "configured to (or set to)" must not mean only "specifically designed to" in hardware. Instead, the expression "a device configured to" may mean that the device is "capable of" operating together with another device or other components. CPU, for example, a "processor configured to (or set to) perform A, B, and C" may mean a dedicated processor (for example, an embedded processor) for performing a corresponding operation or a generic-purpose processor (for example, a central processing unit (CPU) or an application processor) which may perform corresponding operations by executing one or more software programs which are stored in a memory device.

Terms used in this specification are used to describe specified embodiments of the present disclosure and are not intended to limit the scope of the present disclosure. The terms of a singular form may include plural forms unless otherwise specified. Unless otherwise defined herein, all the terms used herein, which include technical or scientific terms, may have the same meaning that is generally understood by a person skilled in the art. It will be further understood that terms, which are defined in a dictionary and commonly used, should also be interpreted as is customary in the relevant related art and not in an idealized or overly formal detect unless expressly so defined herein in various embodiments of the present disclosure. In some cases, even if terms are terms which are defined in the specification, they may not be interpreted to exclude embodiments of the present disclosure.

An electronic device according to various embodiments of the present disclosure may include at least one of smartphones, tablet personal computers (PCs), mobile phones, video telephones, electronic book readers, desktop PCs, laptop PCs, netbook computers, workstations, servers, personal digital assistants (PDAs), portable multimedia players (PMPs), MP3 players, mobile medical devices, cameras, and wearable devices. According to various embodiments of the present disclosure, the wearable devices may include accessories (for example, watches, rings, bracelets, ankle bracelets, glasses, contact lenses, or head-mounted devices (HMDs)), cloth-integrated types (for example, electronic clothes), body-attached types (for example, skin pads or tattoos), or implantable types (for example, implantable circuits).

In some embodiments of the present disclosure, the electronic device may be one of home appliances. The home appliances may include, for example, at least one of a digital video disk (DVD) player, an audio, a refrigerator, an air conditioner, a cleaner, an oven, a microwave oven, a washing machine, an air cleaner, a set-top box, a home automation control panel, a security control panel, a TV box (for example, Samsung HomeSync™, Apple TV™, or Google TV™), a game console (for example, Xbox™ or PlayStation™), an electronic dictionary, an electronic key, a camcorder, or an electronic panel.

In another embodiment of the present disclosure, the electronic device may include at least one of various medical devices (for example, various portable medical measurement devices (a blood glucose meter, a heart rate measuring device, a blood pressure measuring device, and a body temperature measuring device), a magnetic resonance angiography (MRA), a magnetic resonance imaging (MRI) device, a computed tomography (CT) device, a photographing device, and an ultrasonic device), a navigation system, a global navigation satellite system (GNSS), an event data recorder (EDR), a flight data recorder (FDR), a vehicular infotainment device, electronic devices for vessels (for example, a navigation device for vessels and a gyro compass), avionics, a security device, a vehicular head unit, an industrial or home robot, an automatic teller's machine (ATM) of a financial company, a point of sales (POS) of a store, or an internet of things (for example, a bulb, various sensors, an electricity or gas meter, a spring cooler device, a fire alarm device, a thermostat, an electric pole, a toaster, a sporting apparatus, a hot water tank, a heater, and a boiler).

According to some embodiments of the present disclosure, the electronic device may include at least one of a furniture or a part of a building/structure, an electronic board, an electronic signature receiving device, a projector, or various measurement devices (for example, a water service, electricity, gas, or electric wave measuring device). In various embodiments of the present disclosure, the electronic device may be one or a combination of the aforementioned devices. The electronic device according to some embodiments of the present disclosure may be a flexible electronic device. Further, the electronic device according to an embodiment of the present disclosure is not limited to the aforementioned devices, but may include new electronic devices produced due to the development of technologies.

Hereinafter, electronic devices according to an embodiment of the present disclosure will be described with reference to the accompanying drawings. The term "user" used herein may refer to a person who uses an electronic device or may refer to a device (for example, an artificial electronic device) that uses an electronic device.

<FIG> and <FIG> are diagrams of an electronic device, according to an embodiment.

Although an electronic device <NUM> and an electronic device <NUM> are illustrated as a smartphone and a smart watch in <FIG> and <FIG>, the disclosure is not limited thereto. The electronic device <NUM> may be a tablet personal computer (PC) or a laptop PC. The electronic device <NUM> may be a wearable device (e.g., a smart band, a smart necklace, or a smart glass).

Referring to <FIG>, the electronic device <NUM> includes a display <NUM> and a housing (or body) <NUM>.

The display <NUM> may output content such as a text or an image. When a health care (or management) application is executed, the display <NUM> may display a user interface associated with the application. Also, the display <NUM> may display heartbeat information or blood pressure information of a user.

The housing (or body) <NUM> may fix the display <NUM> and may protect various components included in the housing <NUM>. The housing <NUM> may include an optical sensor <NUM>, a processor <NUM>, a memory <NUM>, and a communication circuit, which are necessary to drive the electronic device <NUM>.

The optical sensor <NUM> may include a light emitting unit and a light receiving unit. The light emit part may output a light to the outside. The light receiving unit may receive a light reflected by the external object and may convert the received light to an electrical signal. The light receiving unit may provide a collected signal to the processor <NUM>. The optical sensor <NUM> may be mounted on a back surface <NUM> of the electronic device <NUM>. When the user touches his/her finger on the optical sensor <NUM>, the optical sensor <NUM> may emit a light to the finger of the user and may collect biometric information of the user.

The optical sensor <NUM> may include a Fresnel lens that supports total reflection of a light incident perpendicularly to a sensing surface (or a sensor window or a cover member), at the light emitting unit or the light receiving unit. When the Fresnel lens is disposed at the light emitting unit, a light that is emitted to the outside may be in the form of a collimated light. When the Fresnel lens is disposed at the light receiving unit, light concentration may become higher.

The processor <NUM> may process various data processing and operations for the purpose of driving the electronic device <NUM>. The processor <NUM> may execute an application and may display an execution screen associated with the application in the display <NUM>.

The processor <NUM> may receive information collected through the optical sensor <NUM>. The processor <NUM> may analyze the collected information to provide a variety of information to the user. The processor <NUM> may execute a health care application to display heartbeat information or blood pressure information of the user measured through the optical sensor <NUM>. The processor <NUM> may provide workout information or diet information based on the biometric information of the user.

The memory <NUM> may store various data that are generated in the process of driving the electronic device <NUM>. The memory <NUM> may store the biometric information of the user collected through the optical sensor <NUM>.

Referring to <FIG>, the electronic device <NUM> includes a display <NUM>, a housing (or body) <NUM>, and a strap <NUM>.

The display <NUM> may output content such as a text or an image. When a health care application is executed, the display <NUM> may display a user interface associated with the application. Also, the display <NUM> may display heartbeat information or blood pressure information of a user.

The housing (or body) <NUM> may fix the display <NUM> and may protect various components included in the housing <NUM>. The housing <NUM> may include an optical sensor <NUM>, a processor <NUM>, a memory <NUM>, and a communication circuit, which are necessary to drive the electronic device <NUM>. The housing <NUM> may include a structure that is connectable with the strap <NUM>.

Operations of the optical sensor <NUM>, the processor <NUM>, and the memory <NUM> are the same as or identical to the operations of the optical sensor <NUM>, the processor <NUM>, and the memory <NUM>.

The optical sensor <NUM> may be mounted on a back surface <NUM> of the electronic device <NUM>. When the user wears the electronic device <NUM> on his/her wrist, the optical sensor <NUM> may emit a light to the wrist of the user and may collect biometric information of the user.

The strap <NUM> (or a fixing part or a fastening part) <NUM> may fix the electronic device <NUM> to a portion (e.g., a wrist) <NUM> of the body of the user. The strap <NUM> may include a first portion and a second portion having fastening structures corresponding to each other. The strap <NUM> may be connected to the housing <NUM>.

<FIG> are diagrams of an optical sensor including a Fresnel lens, according to an embodiment.

Referring to <FIG>, an optical sensor <NUM> (e.g., the optical sensor <NUM> of <FIG> or the optical sensor <NUM> of <FIG>) includes a light emitting unit <NUM>, a light receiving unit <NUM>, and a Fresnel lens <NUM> for light reception. The light emitting unit <NUM> may generate an infrared light. The light emitting unit <NUM> may output a collimated light. The light that is generated from the light emitting unit <NUM> may be emitted to the outside through a sensing surface 130a.

The light receiving unit <NUM> may collect a light incident from the outside and may convert the collected light to an electrical signal. The light receiving unit <NUM> may collect a light (hereinafter referred to as a "reflection light") that is reflected by an external object (e.g., a body of the user) after being emitted from the light emitting unit <NUM> and may convert the collected light to an electrical signal. The light receiving unit <NUM> may provide a collected signal to the processor <NUM> or <NUM> in the electronic device <NUM> or <NUM>.

The light emitting unit <NUM> and the light receiving unit <NUM> may be disposed on the same plane. In another embodiment, the light emitting unit <NUM> and the light receiving unit <NUM> may be disposed on different planes, respectively. The light emitting unit <NUM> may protrude more than the light receiving unit <NUM> in a direction facing the sensing surface 130a.

The Fresnel lens <NUM> for light reception may be disposed above the light receiving unit <NUM> (e.g., between the sensing surface 130a and the light receiving unit <NUM>). The Fresnel lens <NUM> for light reception may total reflect and refract the reflection light reflected by the external object (e.g., a body of the user) so as to be induced to the light receiving unit <NUM>. The Fresnel lens <NUM> for light reception may prevent a light passing through the sensing surface 130a from being scattered to a peripheral area in an electronic device, thus improving a light transfer efficiency and an object recognition efficiency. The Fresnel lens <NUM> for light reception may absorb photons in an area wider than the light receiving unit <NUM> so as to be transferred to the light receiving unit <NUM>. This may allow the light receiving unit <NUM> of the narrow area to collect photons in a relatively wide range. The Fresnel lens <NUM> for light reception may be formed of a poly methyl methacrylate (PMMA), acryl, or glass material.

The Fresnel lens <NUM> for light reception may include a center lens <NUM> and a sawtooth lens <NUM>. The center lens <NUM> may be disposed in a center area of the Fresnel lens <NUM> for light reception. The center lens <NUM> may be similar in shape to a general convex lens. A center point of the center lens <NUM> and a center point of the light receiving unit <NUM> may be aligned on a normal perpendicular to the sensing surface 130a.

The sawtooth lens <NUM> may be disposed around the center lens <NUM>. The sawtooth lens <NUM> may be in the form of a circular arc surrounding the center lens <NUM>. As a distance from the center lens <NUM> increases, a circular arc of the sawtooth lens <NUM> may become larger. The sawtooth lens <NUM> may include a plurality of sawtooth lenses, and may be symmetric with respect to the central point of the center lens <NUM>. The sawtooth lens <NUM> may protrude toward the light receiving unit <NUM>.

Through total reflection and refraction, the sawtooth lens <NUM> may induce a reflection light incident perpendicularly to the sensing surface 130a to the light receiving unit <NUM>.

The Fresnel lens <NUM> for light reception may include a notch <NUM>. The notch <NUM> may be in the form of a groove that is formed on a surface, which faces the light receiving unit <NUM>, of the Fresnel lens <NUM> for light reception. The notch <NUM> may prevent a light output from the light emitting unit <NUM> from being introduced directly to the light receiving unit <NUM> without reflection by an external object (cross-talk).

An extension <NUM> of the Fresnel lens <NUM> for light reception may be disposed between the light emitting unit <NUM> and the sensing surface 130a. The extension <NUM> may be integrally formed with the Fresnel lens <NUM> for light reception. The Fresnel lens <NUM> may transmit a light generated from the light emitting unit <NUM>.

Referring to <FIG>, an optical sensor <NUM> (e.g., the optical sensor <NUM> of <FIG> or the optical sensor <NUM> of <FIG>) includes the light emitting unit <NUM>, the light receiving unit <NUM>, and a Fresnel lens <NUM> for light emission.

The Fresnel lens <NUM> for light emission may be disposed above the light emitting unit <NUM> (e.g., between the sensing surface 130a and the light emitting unit <NUM>). The Fresnel lens <NUM> for light emission may total reflect and refract a light generated by the light emitting unit <NUM> so as to be incident perpendicularly to the sensing surface 130a.

A general Fresnel lens may change a direction of an output light up to maximally <NUM> degrees. In contrast, the Fresnel lens <NUM> for light emission, which supports total reflection, may change a direction of an output light up to maximally about <NUM> degrees. As such, a collimated light (or a parallel light) may be incident perpendicularly to the sensing surface 130a. When the collimated light (or the parallel light) is output, it may be easy to measure scattering by an object targeted for measurement. When the propagation of the light is changed to travel in a straight line, the degree of absorption and scattering due to compositions in a human body may be measured more easily by the light receiving unit <NUM>. Also, when the Fresnel lens <NUM> for light emission is applied to a light emitting unit of a distance sensor (e.g., a time of flight (ToF) sensor), the Fresnel lens <NUM> for light emission may be used to measure a distance from an object, thus improving the performance of photographing.

The Fresnel lens <NUM> for light emission may include a center lens <NUM> and a sawtooth lens <NUM>. The center lens <NUM> may be disposed in a center area of the Fresnel lens <NUM> for light emission. The center lens <NUM> may be similar in shape to a general convex lens. In an embodiment, a center point of the center lens <NUM> and a center point of the light emitting unit <NUM> may be aligned on a normal perpendicular to the sensing surface 130a.

The sawtooth lens <NUM> may be disposed in the form of a circular arc surrounding the center lens <NUM>. As a distance from the center lens <NUM> increases, a circular arc of the sawtooth lens <NUM> may become larger. The sawtooth lens <NUM> may include a plurality of sawtooth lenses, and may be symmetric with respect to the central point of the center lens <NUM>. The sawtooth lens <NUM> may protrude toward the light emitting unit <NUM>.

Through refraction and total reflection, the sawtooth lens <NUM> may convert a light generated by the light emitting unit <NUM> to a light perpendicular to the sensing surface 130a. In one sawtooth lens <NUM>, as an output light is refracted at a first surface (an internal surface) and is total reflected at a second surface (an external surface), the output light may be converted to the light perpendicular to the sensing surface 130a.

The Fresnel lens <NUM> for light emission may include a notch <NUM>. The notch <NUM> may be in the form of a groove that is formed on a surface, which faces the light emitting unit <NUM>, of the Fresnel lens <NUM> for light emission. The notch <NUM> may prevent a light output from the light emitting unit <NUM> from being introduced directly to the light receiving unit <NUM> without reflection by an external object (cross-talk).

An extension <NUM> of the Fresnel lens <NUM> for light emission may be disposed between the light receiving unit <NUM> and the sensing surface 130a. The extension <NUM> may be integrally formed with the Fresnel lens <NUM> for light emission. The Fresnel lens <NUM> may transmit a reflection light introduced from the outside.

The light emitting unit <NUM> and the light receiving unit <NUM> may be disposed on different planes, respectively. The light receiving unit <NUM> may further protrude in a direction facing the sensing surface 130a. A separate support member <NUM> may be disposed under the light receiving unit <NUM>. When the light receiving unit <NUM> further protrudes in the direction facing the sensing surface 130a, a light transfer efficiency may be improved.

Referring to <FIG>, an optical sensor <NUM> (e.g., the optical sensor <NUM> of <FIG> or the optical sensor <NUM> of <FIG>) includes the light emitting unit <NUM>, the light receiving unit <NUM>, and a plurality of Fresnel lenses <NUM> (including the Fresnel lens <NUM> for light reception and the Fresnel lens <NUM> for light emission).

When the Fresnel lens <NUM> for light reception and the Fresnel lens <NUM> for light emission are integrally formed is illustrated in <FIG>, but the disclosure is not limited thereto. The Fresnel lens <NUM> for light reception and the Fresnel lens <NUM> for light emission may be separately formed and disposed.

Functions or operations of the light emitting unit <NUM>, the light receiving unit <NUM>, the Fresnel lens <NUM> for light reception, and the Fresnel lens <NUM> for light emission may be the same as or similar to the functions or operations of the corresponding components of <FIG> or <FIG>.

When the Fresnel lens <NUM> for light emission and the Fresnel lens <NUM> for light reception are respectively applied to the light emitting unit <NUM> and the light receiving unit <NUM>, a signal-to-noise ratio may be higher than that of the optical sensor <NUM> of <FIG> or the optical sensor <NUM> of <FIG>.

The Fresnel lens <NUM> for light emission and the Fresnel lens <NUM> for light reception may protrude in the same direction. Both the Fresnel lens <NUM> for light emission and the Fresnel lens <NUM> for light reception may protrude in a direction facing away from the sensing surface 130a.

When the sensing surface 130a and the Fresnel lenses <NUM> and <NUM> are separated is illustrated in <FIG>, but the disclosure is not limited thereto. The sensing surface 130a and the Fresnel lenses <NUM> and <NUM> may be in contact with each other.

<FIG> is a diagram of light traveling in a sawtooth lens of a Fresnel lens, according to an embodiment. Although <FIG> illustrates a reflection light incident to a light receiving unit, the disclosure is also applicable to a light generated from a light emitting unit. In a light emitting unit and a Fresnel lens for light emission, a travel path of a light may be opposite to a travel path illustrated in <FIG>.

Referring to <FIG>, the Fresnel lens <NUM> for light reception may be disposed above the light receiving unit <NUM> (e.g., between the sensing surface 130a and the light receiving unit <NUM>). The Fresnel lens <NUM> for light reception may total reflect and refract a reflection light L1 reflected by an external object (e.g., a body of the user) so as to be induced to the light receiving unit <NUM>. A center point "<NUM>" of the Fresnel lens <NUM> for light reception and a center point of the light receiving unit <NUM> may be aligned on a normal perpendicular to the sensing surface 130a.

The Fresnel lens <NUM> for light reception may include one or more sawtooth lenses <NUM>. The sawtooth lens <NUM> may include an internal surface 252a relatively close to the center point "<NUM>" of the Fresnel lens <NUM> for light reception and an external surface 252b relatively distant from the center point "<NUM>".

The internal surface 252a may form a first angle with the sensing surface 130a. The external surface 252b may form a second angle with the sensing surface 130a. The first angle may be greater than the second angle.

An incident light L1 (having an incidence angle i1) incident perpendicularly to the sensing surface 130a may be total reflected at the external surface 252b. When using the Fresnel lens <NUM> for light reception, which is formed of a poly methyl methacrylate (PMMA) material, a refractive index of the sawtooth lens <NUM> may be about <NUM>. Because a refractive index of air is "<NUM>", the incidence angle i1 of the incident light L1 perpendicular to the sensing surface 130a is greater than about <NUM> degrees, the total reflection may occur at the external surface 252b.

A placement angle, a length, or a curvature of the external surface 252b may be determined based on a material characteristic (e.g., a refractive index) of the Fresnel lens <NUM> for light reception and a distance Rn between the sawtooth lens <NUM> and the center point "<NUM>".

When the reflection light L1 is total reflected at the external surface 252b, the incident light L1 may be induced toward the internal surface 252a without being output to the outside of the sawtooth lens <NUM>.

The internal surface 252a may refract a light L2 (having an incidence angle i2) total reflected at the external surface 252b (at a refraction angle of α) so as to be induced to the light receiving unit <NUM>. A placement angle, a length, or a curvature of the internal surface 252a may be determined based on the material characteristic (e.g., a refractive index) of the Fresnel lens <NUM> for light reception and the distance Rn between the sawtooth lens <NUM> and the center point "<NUM>".

A refracted light L3 may be introduced to the light receiving unit <NUM> and may then be converted to an electrical signal.

A value of a convergent angle Θ between a normal 130a1 of the sensing surface 130a and the light L3 refracted through the internal surface 252a may vary with the incidence angle i1. Through the convergent angle Θ, an angle between the internal surface 252a and the external surface 252b of the sawtooth lens <NUM> that total reflects the incident light L1 may also be determined.

A relationship between an incidence angle and a reflection angle may be determined by Equation <NUM> and Equation <NUM> below:<MAT> <MAT>.

When the first incidence angle i1 is about <NUM> degrees, the convergent angle Θ of the Fresnel lens <NUM> for light reception may be about <NUM> degrees, and the second incidence angle i2 may be about <NUM>. Here, tan(Θ) may be determined by the distance Rn between the external surface 252b of the sawtooth lens <NUM> and the center point "<NUM>" of the Fresnel lens <NUM> for light reception and a focal distance "F" of the Fresnel lens <NUM> for light reception (tan(Θ)=Rn/F).

When the first incidence angle i1 is greater than about <NUM> degrees, the total reflection may occur at the external surface 252b of the Fresnel lens <NUM> for light reception, which is formed of the PMMA material. In the Fresnel lens <NUM> for light reception, which is formed of the PMMA material, an angle between the internal surface 252a and the external surface 252b of the sawtooth lens <NUM> or a shape of the internal surface 252a and the external surface 252b may be determined by using the convergent angle Θ that is calculated when the first incidence angle i1 is greater than about <NUM> degrees.

When using the Fresnel lens <NUM> for light reception formed of a poly methyl methacrylate (PMMA) material, when tan(Θ) > <NUM>, the total reflection may occur at the external surface 252b.

<FIG> is a diagram of transmittance of a lens according to a convergent angle Θ of a Fresnel lens for light reception, according to an embodiment.

Referring to <FIG>, light transmittance of a general Fresnel lens <NUM> and light transmittance of a Fresnel lens <NUM> that supports total reflection may vary with a convergent angle Θ. When the convergent angle Θ is not greater than about <NUM> degrees, the light transmittance of the general Fresnel lens <NUM> may be greater than the light transmittance of the Fresnel lens <NUM> supporting total reflection. In contrast, when the convergent angle Θ is not smaller than about <NUM> degrees, the light transmittance of the Fresnel lens <NUM> supporting total reflection may be greater than the light transmittance of the general Fresnel lens <NUM>. When using the Fresnel lens <NUM> supporting total reflection in a mounting environment in which the convergent angle Θ is not smaller than about <NUM> degrees, a light transfer efficiency may increase.

<FIG> is a diagram of a structure of a notch formed in a Fresnel lens, according to an embodiment. In <FIG>, a description will be given with respect to the Fresnel lens <NUM> for light reception, but the description may also be applied to the Fresnel lens <NUM> for light emission.

Referring to <FIG>, the Fresnel lens <NUM> for light reception includes the notch <NUM>, which prevents a light output from the light emitting unit <NUM> from being introduced directly to the light receiving unit <NUM> without reflection by an external object (cross-talk).

The notch <NUM> may be disposed between a center area 250a and a peripheral area 250b of the Fresnel lens <NUM> for light reception. The notch <NUM> may be in the form of a circle or a circular arc surrounding the center area 250a. The notch <NUM> may be in the form of a groove that is formed on a surface, which faces the light receiving unit <NUM>, of the Fresnel lens <NUM> for light reception.

The Fresnel lens <NUM> may include a support structure <NUM> (or a portion, in which a groove is not formed, of the notch <NUM>). The support structure <NUM> may separate the notch <NUM>. The support structure <NUM> may prevent the Fresnel lens <NUM> for light reception from be damaged when the notch <NUM> is formed. The support structure <NUM> may be formed parallel to a surface, which faces the light receiving unit <NUM>, of the Fresnel lens <NUM> for light reception. The support structure <NUM> may be a portion where the notch <NUM> is not formed and the center area 250a and the peripheral area 250b are connected flatwise.

<FIG> is a diagram of an embodiment in which a reinforcement material is inserted in a notch, according to the invention.

The Fresnel lens <NUM> for light emission and the Fresnel lens <NUM> for light reception may be integrally formed.

The Fresnel lens <NUM> for light emission and the Fresnel lens <NUM> for light reception may include the notch <NUM> and the notch <NUM>, respectively. The notches <NUM> and <NUM> formed in the Fresnel lens <NUM> for light emission and the Fresnel lens <NUM> for light reception may be integrated to form one groove.

The notches <NUM> and <NUM> may prevent a light output from the light emitting unit <NUM> from being introduced directly to the light receiving unit <NUM> without reflection by an external object (cross-talk).

The notches <NUM> and <NUM> may be filled with reinforcement materials 255a and 266a of a good light absorption rate. The notches <NUM> and <NUM> may be filled all or partially with the reinforcement materials 255a and 266a.

<FIG> is a diagram of a layout of an optical sensor including one light emitting unit and a plurality of light receiving units, according to an embodiment.

Referring to <FIG>, an optical sensor <NUM> (e.g., the optical sensor <NUM> of <FIG> or the optical sensor <NUM> of <FIG>) includes one light emitting unit <NUM>, the Fresnel lens <NUM> for light emission, and a plurality of light receiving units <NUM> (e.g., detectors).

The light emitting unit <NUM> may be disposed in a central portion of the optical sensor <NUM>. The light emitting unit <NUM> may be in the form where a plurality of small light sources are combined. The Fresnel lens <NUM> for light emission may be disposed above the light emitting unit <NUM> (or a surface of the light emitting unit <NUM>, from which a light is output or which faces a sensing surface).

The Fresnel lens <NUM> for light emission includes the notch <NUM>. The notch <NUM> may be disposed between the light emitting unit <NUM> and each of the light receiving units <NUM>.

The plurality of light receiving units <NUM> may convert a reflection light, which is reflected by an external object after being generated from the light receiving unit <NUM>, to an electrical signal. The plurality of light receiving units <NUM> may collect different reflection lights based on positions where the light receiving units <NUM> are disposed. A processor may collect biometric information of the user by comparing information collected by each light receiving unit <NUM> and position information of each light receiving unit <NUM> and analyzing comparison results.

A separate isolator for light isolation may not be disposed between the light emitting unit <NUM> and the plurality of light receiving units <NUM>. A characteristic of a light traveling in a straight line may be improved through the Fresnel lens <NUM> for light emission, thus reducing the probability of direct introduction to the light receiving units <NUM> adjacent thereto. Also, the notch <NUM> may make light isolation easy, and thus, the crosstalk of light may be reduced.

A distance between the light emitting unit <NUM> and the plurality of light receiving units <NUM> may be shorter than when an isolator is disposed, and a space where the optical sensor <NUM> is mounted may be reduced.

One or more indium tin oxide (ITO) electrodes may be formed in the Fresnel lens <NUM>. An indium tin oxide (ITO) electrode that is a transparent film may transmit a light. The ITO electrode may be connected to at least one of a touch sensor, an electrocardiogram (ECG) sensor, or a body fat mass/skeletal muscle mass (or bioelectrical impedance analysis (BIA)) sensor, through a conductive line. When a plurality of ITO electrodes are provided, a capacitance may be formed between the ITO electrodes. The touch sensor, the ECG sensor, or the body fat mass/skeletal muscle mass (or BIA) sensor may sense a change in the capacitance between the ITO electrodes to recognize whether a touch is made by a portion of a body of the user. Various sensing information may be collected. The ECG sensor or the body fat mass/skeletal muscle mass (or BIA) sensor may connect one ITO electrode to (+) terminal and the other electrode to (-) terminal of power source to measure the electrocardiogram (ECG) or the body fat mass/skeletal muscle mass.

<FIG> is a diagram of an optical sensor including a Fresnel lens at each of a light emitting unit and a light receiving unit, according to an embodiment.

Referring to <FIG>, an optical sensor <NUM> (e.g., the optical sensor <NUM> of <FIG> or the optical sensor <NUM> of <FIG>) includes the Fresnel lenses <NUM> for light reception, which correspond to the plurality of light receiving units <NUM>, unlike the optical sensor <NUM> of <FIG>. Each Fresnel lens <NUM> for light reception may include the notch <NUM>.

When a Fresnel lens is applied to each of the light emitting unit <NUM> and the light receiving unit <NUM>, a light transfer efficiency may be improved. The Fresnel lens <NUM> for light emission corresponding to the light emitting unit <NUM> may change a light generated from the light emitting unit <NUM> to a collimated light so as to be induced maximally to a sensing surface. The Fresnel lens <NUM> for light reception of the light receiving unit <NUM> may concentrate a light reflected by an external object into the light receiving unit <NUM>, thus making light collection of the light receiving unit <NUM> easy. This may mean that a signal-to-noise ratio is maximized.

<FIG> is a diagram of an optical sensor including one light emitting unit and one light receiving unit, according to an embodiment.

Referring to <FIG>, an optical sensor <NUM> (e.g., the optical sensor <NUM> of <FIG> or the optical sensor <NUM> of <FIG>) includes one light emitting unit <NUM>, the Fresnel lens <NUM> for light emission, one light receiving unit <NUM>, and the Fresnel lens <NUM> for light reception. The Fresnel lens <NUM> for light emission and the Fresnel lens <NUM> for light reception may include the notch <NUM> and the notch <NUM>, respectively.

The optical sensor <NUM> may include one light emitting unit <NUM> and one light receiving unit <NUM> and may be mounted in a smaller space than the optical sensors <NUM> and <NUM> of <FIG> and <FIG>. The light emitting unit <NUM> and the light receiving unit <NUM> may be installed without a separate isolator, and thus, a mounting efficiency may be improved. The optical sensor <NUM> may be installed in a wearable device, which has a relatively small mounting space, such as a smart necklace or a smart ring.

<FIG> is a diagram of an optical sensor including a Fresnel lens at each of a plurality of light emitting units, according to an embodiment.

Referring to <FIG>, the plurality of light emitting units <NUM> may be arranged in a specified shape (e.g., in a tetragonal or triangular shape). The Fresnel lens <NUM> for light emission may be disposed at each of the plurality of light emitting units <NUM>.

Lights emitted from the plurality of light emitting units <NUM> through the Fresnel lenses <NUM> for light emission may be reflected by an external object and may be transferred to the plurality of light receiving units <NUM> adjacent thereto. Each of the plurality of light receiving units <NUM> may receive a light generated from the light emitting unit <NUM> adjacent thereto as a reflection light of the highest intensity.

<FIG> is a diagram an example in which a pattern surface of a Fresnel lens faces a sensing surface, according to an embodiment.

Referring to <FIG>, an optical sensor <NUM> (e.g., the optical sensor <NUM> of <FIG> or the optical sensor <NUM> of <FIG>) includes a light emitting unit <NUM>, a light receiving unit <NUM>, and a plurality of Fresnel lenses <NUM> (including a Fresnel lens <NUM> for light emission and a Fresnel lens <NUM> for light reception).

The light emitting unit <NUM> may generate an infrared light. The light emitting unit <NUM> may output a collimated light. The light that is generated from the light emitting unit <NUM> may be emitted to the outside through the sensing surface 130a.

The light receiving unit <NUM> may collect a light incident from the outside and may convert the collected light to an electrical signal. The light receiving unit <NUM> may collect a reflection light reflected by an external object (e.g., a body of the user) after being emitted from the light emitting unit <NUM> and may convert the collected light to an electrical signal.

The Fresnel lens <NUM> for light emission may be disposed above the light emitting unit <NUM> (e.g., between the sensing surface 130a and the light emitting unit <NUM>). A sawtooth-shaped pattern surface of the Fresnel lens <NUM> for light emission may be disposed to face the sensing surface 130a. The Fresnel lens <NUM> for light emission may total reflect and refract a light generated by the light emitting unit <NUM> so as to be incident to the sensing surface 130a.

The Fresnel lens <NUM> for light emission may support total reflection to change a direction of the light output from the light emitting unit <NUM> up to maximally about <NUM> degrees. As such, in the light emitting unit <NUM>, an incident light that is parallel to the Fresnel lens <NUM> for light emission may be concentrated into a first point "A" of the sensing surface 130a.

The Fresnel lens <NUM> for light reception may be disposed above the light receiving unit <NUM> (e.g., between the sensing surface 130a and the light receiving unit <NUM>). A tooth-shaped pattern surface of the Fresnel lens <NUM> for light reception may be disposed to face the sensing surface 130a. The Fresnel lens <NUM> for light reception may refract and total reflect the reflection light reflected by an external object (e.g., a body of the user) so as to be induced to the light receiving unit <NUM>. The Fresnel lens <NUM> for light reception may allow a light reflected from a second point "B" of the sensing surface 130a to be spread on the whole area of the light receiving unit <NUM>.

When both the Fresnel lens <NUM> for light emission and the Fresnel lens <NUM> for light reception face the sensing surface 130a is illustrated in <FIG>, but the disclosure is not limited thereto. One of the Fresnel lens <NUM> for light emission and the Fresnel lens <NUM> for light reception may be disposed to face the sensing surface 130a, and the other thereof may be disposed to face the light emitting unit <NUM> or the light receiving unit <NUM>.

<FIG> illustrates a block diagram of an electronic device <NUM> in a network environment <NUM>, according to various embodiments. An electronic device according to various embodiments of this disclosure may include various forms of devices. For example, the electronic device may include at least one of, for example, portable communication devices (e.g., smartphones), computer devices (e.g., personal digital assistants (PDAs),tablet personal computers (PCs), laptop PCs, desktop PCs, workstations, or servers), portable multimedia devices (e.g., electronic book readers or Motion Picture Experts Group (MPEG-<NUM> or MPEG-<NUM>) Audio Layer <NUM> (MP3) players), portable medical devices (e.g., heartbeat measuring devices, blood glucose monitoring devices, blood pressure measuring devices, and body temperature measuring devices), cameras, or wearable devices. The wearable device may include at least one of an accessory type (e.g., watches, rings, bracelets, anklets, necklaces, glasses, contact lens, or head-mounted-devices (HMDs)), a fabric or garment-integrated type (e.g., an electronic apparel), a body-attached type (e.g., a skin pad or tattoos), or a bio-implantable type (e.g., an implantable circuit). According to various embodiments, the electronic device may include at least one of, for example, televisions (TVs), digital versatile disk (DVD) players, audios, audio accessory devices (e.g., speakers, headphones, or headsets), refrigerators, air conditioners, cleaners, ovens, microwave ovens, washing machines, air cleaners, set-top boxes, home automation control panels, security control panels, game consoles, electronic dictionaries, electronic keys, camcorders, or electronic picture frames.

In another embodiment, the electronic device may include at least one of navigation devices, satellite navigation system (e.g., Global Navigation Satellite System (GNSS)), event data recorders (EDRs) (e.g., black box for a car, a ship, or a plane), vehicle infotainment devices (e.g., head-up display for vehicle), industrial or home robots, drones, automatic teller's machines (ATMs), points of sales (POSs), measuring instruments (e.g., water meters, electricity meters, or gas meters), or internet of things (e.g., light bulbs, sprinkler devices, fire alarms, thermostats, or street lamps). The electronic device according to an embodiment of this disclosure may not be limited to the above-described devices, and may provide functions of a plurality of devices like smartphones which has measurement function of personal biometric information (e.g., heart rate or blood glucose). In this disclosure, the term "user" may refer to a person who uses an electronic device or may refer to a device (e.g., an artificial intelligence electronic device) that uses the electronic device.

Referring to <FIG>, under the network environment <NUM>, the electronic device <NUM> (e.g., the electronic device <NUM>) may communicate with an electronic device <NUM> through local wireless communication <NUM> or may communication with an electronic device <NUM> or a server <NUM> through a network <NUM>. According to an embodiment, the electronic device <NUM> may communicate with the electronic device <NUM> through the server <NUM>.

According to an embodiment, the electronic device <NUM> may include a bus <NUM>, a processor <NUM>, a memory <NUM>, an input device <NUM> (e.g., a micro-phone or a mouse), a display device <NUM>, an audio module <NUM>, a sensor module <NUM>, an interface <NUM>, a haptic module <NUM>, a camera module <NUM>, a power management module <NUM>, a battery <NUM>, a communication module <NUM>, and a subscriber identification module <NUM>. According to an embodiment, the electronic device <NUM> may not include at least one (e.g., the display device <NUM> or the camera module <NUM>) of the above-described elements or may further include other element(s).

The bus <NUM> may interconnect the above-described elements <NUM> to <NUM> and may include a circuit for conveying signals (e.g., a control message or data) between the above-described elements. The processor <NUM> may include one or more of a central processing unit (CPU), an application processor (AP), a graphic processing unit (GPU), an image signal processor (ISP) of a camera or a communication processor (CP). According to an embodiment, the processor <NUM> may be implemented with a system on chip (SoC) or a system in package (SiP). For example, the processor <NUM> may drive an operating system (OS) or an application to control at least one of another element (e.g., hardware or software element) connected to the processor <NUM> and may process and compute various data. The processor <NUM> may load a command or data, which is received from at least one of other elements (e.g., the communication module <NUM>), into a volatile memory <NUM> to process the command or data and may store the result data into a nonvolatile memory <NUM>.

The memory <NUM> may include, for example, the volatile memory <NUM> or the nonvolatile memory <NUM>. The volatile memory <NUM> may include, for example, a random access memory (RAM) (e.g., a dynamic RAM (DRAM), a static RAM (SRAM), or a synchronous DRAM (SDRAM)). The nonvolatile memory <NUM> may include, for example, a one time programmable read-only memory (OTPROM), a programmable read-only memory (PROM),an erasable PROM (EPROM), an electrically EPROM (EEPROM), a mask ROM, a flash ROM, a flash memory, a hard disk drive (HDD), or a solid-state drive (SSD). In addition, the nonvolatile memory <NUM> may be configured in the form of an internal memory <NUM> or the form of an external memory <NUM> which is available through connection only if necessary, according to the connection with the electronic device <NUM>. The external memory <NUM> may further include a flash drive such as compact flash (CF), secure digital (SD), micro secure digital (Micro-SD), mini secure digital (Mini-SD), extreme digital (xD), a multimedia card (MMC), or a memory stick. The external memory <NUM> may be operatively or physically connected with the electronic device <NUM> in a wired manner (e.g., a cable or a universal serial bus (USB)) or a wireless (e.g., Bluetooth) manner.

For example, the memory <NUM> may store, for example, at least one different software element, such as a command or data associated with the program <NUM>, of the electronic device <NUM>. The program <NUM> may include, for example, a kernel <NUM>, a library <NUM>, an application framework <NUM> or an application program (interchangeably, "application") <NUM>.

The input device <NUM> may include a microphone, a mouse, or a keyboard. According to an embodiment, the keyboard may include a keyboard physically connected or a virtual keyboard displayed through the display <NUM>.

The display <NUM> may include a display, a hologram device or a projector, and a control circuit to control a relevant device. The display may include, for example, a liquid crystal display (LCD), a light emitting diode (LED) display, an organic LED (OLED) display, a microelectromechanical systems (MEMS) display, or an electronic paper display. According to an embodiment, the display may be flexibly, transparently, or wearably implemented. The display may include a touch circuitry, which is able to detect a user's input such as a gesture input, a proximity input, or a hovering input or a pressure sensor (interchangeably, a force sensor) which is able to measure the intensity of the pressure by the touch. The touch circuit or the pressure sensor may be implemented integrally with the display or may be implemented with at least one sensor separately from the display. The hologram device may show a stereoscopic image in a space using interference of light. The projector may project light onto a screen to display an image. The screen may be located inside or outside the electronic device <NUM>.

The audio module <NUM> may convert, for example, from a sound into an electrical signal or from an electrical signal into the sound. According to an embodiment, the audio module <NUM> may acquire sound through the input device <NUM> (e.g., a microphone) or may output sound through an output device (not illustrated) (e.g., a speaker or a receiver) included in the electronic device <NUM>, an external electronic device (e.g., the electronic device <NUM> (e.g., a wireless speaker or a wireless headphone)) or an electronic device <NUM> (e.g., a wired speaker or a wired headphone)connected with the electronic device <NUM>.

The sensor module <NUM> may measure or detect, for example, an internal operating state (e.g., power or temperature) of the electronic device 2001or an external environment state (e.g., an altitude, a humidity, or brightness) to generate an electrical signal or a data value corresponding to the information of the measured state or the detected state. The sensor module <NUM> may include, for example, at least one of a gesture sensor, a gyro sensor, a barometric pressure sensor, a magnetic sensor, an acceleration sensor, a grip sensor, a proximity sensor, a color sensor (e.g., a red, green, blue (RGB) sensor), an infrared sensor, a biometric sensor (e.g., an iris sensor, a fingerprint senor, a heartbeat rate monitoring (HRM) sensor, an e-nose sensor, an electromyography (EMG) sensor, an electroencephalogram (EEG) sensor, an electrocardiogram (ECG) sensor), a temperature sensor, a humidity sensor, an illuminance sensor, or an UV sensor. The sensor module <NUM> may further include a control circuit for controlling at least one or more sensors included therein. According to an embodiment, the sensor module <NUM> may be controlled by using the processor <NUM> or a processor (e.g., a sensor hub) separate from the processor <NUM>. In the case that the separate processor (e.g., a sensor hub) is used, while the processor <NUM> is in a sleep state, the separate processor may operate without awakening the processor <NUM> to control at least a portion of the operation or the state of the sensor module <NUM>.

According to an embodiment, the interface <NUM> may include a high definition multimedia interface (HDMI), a universal serial bus (USB), an optical interface, a recommended standard <NUM> (RS-<NUM>), a D-subminiature (D-sub), a mobile high-definition link (MHL) interface, a SD card/MMC(multi-media card) interface, or an audio interface. A connector <NUM> may physically connect the electronic device <NUM> and the electronic device <NUM>. According to an embodiment, the connector <NUM> may include, for example, an USB connector, an SD card/MMC connector, or an audio connector (e.g., a headphone connector).

The haptic module <NUM> may convert an electrical signal into mechanical stimulation (e.g., vibration or motion) or into electrical stimulation. For example, the haptic module <NUM> may apply tactile or kinesthetic stimulation to a user.

The camera module <NUM> may capture, for example, a still image and a moving picture. According to an embodiment, the camera module <NUM> may include at least one lens (e.g., a wide-angle lens and a telephoto lens, or a front lens and a rear lens), an image sensor, an image signal processor, or a flash (e.g., a light emitting diode or a xenon lamp).

The power management module <NUM>, which is to manage the power of the electronic device <NUM>, may constitute at least a portion of a power management integrated circuit (PMIC).

The battery <NUM> may include a primary cell, a secondary cell, or a fuel cell and may be recharged by an external power source to supply power at least one element of the electronic device <NUM>.

The communication module <NUM> may establish a communication channel between the electronic device <NUM> and an external device (e.g., the first external electronic device <NUM>, the second external electronic device <NUM>, or the server <NUM>). The communication module <NUM> may support wired communication or wireless communication through the established communication channel. According to an embodiment, the communication module <NUM> may include a wireless communication module <NUM> or a wired communication module <NUM>. The communication module <NUM> may communicate with the external device (e.g., the first external electronic device <NUM>, the second external electronic device <NUM>, or the server <NUM>)through a first network <NUM> (e.g. a wireless local area network such as Bluetooth or infrared data association (IrDA)) or a second network <NUM> (e.g., a wireless wide area network such as a cellular network) through a relevant module among the wireless communication module <NUM> or the wired communication module <NUM>.

The wireless communication module <NUM> may support, for example, cellular communication, local wireless communication, global navigation satellite system (GNSS) communication. The cellular communication may include, for example, long-term evolution (LTE), LTE Advance (LTE-A), code division multiple access (CMA), wideband CDMA (WCDMA), universal mobile telecommunications system (UMTS), wireless broadband (WiBro), or global system for mobile communications (GSM). The local wireless communication may include wireless fidelity (Wi-Fi), WiFi Direct, light fidelity (Li-Fi), Bluetooth, Bluetooth low energy (BLE), Zigbee, near field communication (NFC), magnetic secure transmission (MST), radio frequency (RF), or a body area network (BAN). The GNSS may include at least one of a global positioning system (GPS), a global navigation satellite system (Glonass), Beidou Navigation Satellite System (Beidou), the European global satellite-based navigation system (Galileo), or the like. In the present disclosure, "GPS" and "GNSS" may be interchangeably used.

According to an embodiment, when the wireless communication module <NUM> supports cellar communication, the wireless communication module <NUM> may, for example, identify or authenticate the electronic device <NUM> within a communication network using the subscriber identification module (e.g., a SIM card) <NUM>. According to an embodiment, the wireless communication module <NUM> may include a communication processor (CP) separate from the processor <NUM> (e.g., an application processor (AP)). In this case, the communication processor may perform at least a portion of functions associated with at least one of elements <NUM> to <NUM> of the electronic device 2001in substitute for the processor <NUM> when the processor <NUM> is in an inactive (sleep) state, and together with the processor <NUM> when the processor <NUM> is in an active state. According to an embodiment, the wireless communication module <NUM> may include a plurality of communication modules, each supporting only a relevant communication scheme among cellular communication, local wireless communication, or a GNSS communication.

The wired communication module <NUM> may include, for example, include a local area network (LAN) service, a power line communication, or a plain old telephone service (POTS).

For example, the first network <NUM> may employ, for example, WiFi direct or Bluetooth for transmitting or receiving commands or data through wireless direct connection between the electronic device <NUM> and the first external electronic device <NUM>. The second network <NUM> may include a telecommunication network (e.g., a computer network such as a LAN or a WAN, the Internet or a telephone network) for transmitting or receiving commands or data between the electronic device <NUM> and the second electronic device <NUM>.

According to various embodiments, the commands or the data may be transmitted or received between the electronic device <NUM> and the second external electronic device <NUM> through the server <NUM> connected with the second network <NUM>. Each of the first and second external electronic devices <NUM> and <NUM> may be a device of which the type is different from or the same as that of the electronic device <NUM>. According to various embodiments, all or a part of operations that the electronic device <NUM> will perform may be executed by another or a plurality of electronic devices (e.g., the electronic devices <NUM> and <NUM> or the server <NUM>). According to an embodiment, in the case that the electronic device <NUM> executes any function or service automatically or in response to a request, the electronic device <NUM> may not perform the function or the service internally, but may alternatively or additionally transmit requests for at least a part of a function associated with the electronic device <NUM> to any other device (e.g., the electronic device <NUM> or <NUM> or the server <NUM>). The other electronic device (e.g., the electronic device <NUM> or <NUM> or the server <NUM>) may execute the requested function or additional function and may transmit the execution result to the electronic device <NUM>. The electronic device <NUM> may provide the requested function or service using the received result or may additionally process the received result to provide the requested function or service. To this end, for example, cloud computing, distributed computing, or client-server computing may be used.

Claim 1:
An electronic device (<NUM>,<NUM>) comprising:
a housing (<NUM>,<NUM>) including a sensing surface (130a);
a light emitting unit (<NUM>) configured to output a light through the sensing surface (130a);
a light receiving unit (<NUM>) configured to collect a reflection light reflected from an external object in contact with the sensing surface (130a), after the light is output from the light emitting unit (<NUM>), wherein the reflection light is introduced in a direction perpendicular to the sensing surface (130a); and
a first Fresnel lens (<NUM>) disposed between the light receiving unit (<NUM>) and the sensing surface (130a),
wherein a first surface (252b) of the first Fresnel lens (<NUM>) totally reflects the reflection light, , and a second surface (252a) of the first Fresnel lens (<NUM>) refracts the totally reflected light so as to be introduced to the light receiving unit (<NUM>),
wherein the first Fresnel lens (<NUM>) includes a notch (<NUM>) between a point corresponding to the light emitting unit (<NUM>) and a point corresponding to the light receiving unit (<NUM>), so as to prevent light output from the light emitting unit (<NUM>) from being introduced directly to the light receiving unit (<NUM>) without reflection by an external object,
wherein the electronic device (<NUM>, <NUM>) further comprises a reinforcement material (255a) satisfying a specified light absorption rate in the notch (<NUM>).