KR102232467B1 - Ppg sensor package - Google Patents

Abstract

The present invention can provide a PPG sensor package capable of effectively detecting a blood flow signal from a PPG signal even under a user's movement because the amount of light received through the light receiving unit can be increased.
In addition, the present invention can provide a PPG sensor package that can be mounted in a wearable device to efficiently detect a blood flow signal of a human body and easily manage health information.

Description

PPG sensor package {PPG SENSOR PACKAGE}

The present invention relates to a PPG sensor package, and more particularly, to a PPG sensor package capable of effectively detecting a blood flow signal from a PPG signal even under a user's movement.

With the recent increase in interest in health management, there is a growing interest and demand for healthcare devices that can check and manage their own health anytime, anywhere, as well as hospitals. Among them, the photo-electromography (PPG) is a method of measuring health information such as heart rate by measuring the amount of blood flow flowing through blood vessels. In particular, the heart rate information can be easily measured.It is a method of measuring the heart rate through the volume change of the blood vessel that appears during the relaxation and contraction of the heart.Usually, red light or infrared light is irradiated to the blood vessel and transmitted or reflected red light Alternatively, the heart rate can be measured by measuring the amount of change in the infrared light (the amount of change in blood flow). However, the optical volume pulse wave method has many difficulties in reliable heart rate measurement due to individual physical differences caused by fixing a heart rate sensor (PPG sensor) at a certain point due to motion noise generated by movement and physical differences between individuals. come.

In general, PPG is a method of extracting information related to heartbeat using a predetermined number of LEDs and photodetectors. Since heart rate detection using PPG is a simple sensor module that can be measured through only one contact point with the body, it does not cause inconvenience to the user compared to the method using an electrocardiogram (ECG) that requires two or more electrodes to be attached. It is much more suitable for medical or non-medical purposes. On the other hand, the PPG signal has a disadvantage in that even a slight movement causes a large amplitude of motion noise. Such a motion noise may be defined as a noise signal due to vibration and small movements of the body when detecting a heartbeat, and therefore, removal of the motion noise is required for heart rate measurement with high reliability.

In this regard, Japanese Patent Laid-Open Publication No. 1999-9564 discloses a heart function diagnostic apparatus for diagnosing heart function through heart rate and HRV frequency analysis using various pulse wave measuring means including a PPG sensor. However, the heart function diagnosis device is composed of a glasses type, a necklace type, and a watch type, and although an acceleration sensor is used for the purpose of warning about movement, it is difficult to detect an accurate signal when the user is still moving, so it is difficult to detect an accurate heart rate. This is difficult, and when mounted in a wearable device, there is a problem in that signal measurement efficiency is lowered.

Korean Registered Patent Publication 10-1858211

The present invention was conceived to solve the above-described problems, and the problem to be solved by the present invention is to provide a PPG sensor package capable of effective blood flow signal detection from a PPG signal even under a user's movement due to excellent accuracy when detecting a PPG signal. will be.

In order to solve the above problems, the present invention is a base substrate; A light-emitting unit coupled to an upper portion of the base substrate; A plurality of light-receiving units coupled to an upper portion of the base substrate and symmetrically disposed around the light-emitting unit; A light blocking member coupled to the base substrate, forming an accommodation space for accommodating the light emitting part and the light receiving part, and blocking light between the light emitting part and the light receiving part; A light-emitting part optical film coupled to the receiving space in which the light-emitting part is accommodated and including a diffusion sheet; And a light-receiving part optical film coupled to the receiving space in which the light-receiving part is accommodated and including a prism sheet.

According to a preferred embodiment of the present invention, the optical film coupled to the receiving space may be formed on the light-emitting unit and the light-receiving unit by combining at least a portion of the light blocking member.

According to a preferred embodiment of the present invention, the upper surface of the light blocking member may be located above the upper surface of the optical film.

According to a preferred embodiment of the present invention, the accommodation space may be formed by being divided into a partition wall shape by a light blocking member.

According to a preferred embodiment of the present invention, the light emitting part optical film may be a composite sheet further including any one or more of a prism sheet or a microlens sheet, and including a plurality of sheets in an integrated state.

According to a preferred embodiment of the present invention, the optical film of the light receiving unit may be a composite sheet further including at least one of a reflective sheet or a microlens sheet, and including a plurality of sheets in an integrated state.

According to a preferred embodiment of the present invention, the light-emitting unit optical film and the light-receiving unit optical film may be formed to be spaced apart from the light-emitting surface of the light-emitting unit and the light-receiving surface of the light-receiving unit, respectively.

According to a preferred embodiment of the present invention, the plurality of light-receiving units are paired with each other, and one of the light-receiving units paired with each of the two may be disposed to face the other light-receiving unit around the light-emitting unit.

According to a preferred embodiment of the present invention, all of the plurality of light-receiving units may be disposed to be spaced apart by the same distance from the light-emitting unit.

According to a preferred embodiment of the present invention, the optical films of the light-receiving unit coupled to the receiving space in which the light-receiving units are paired with each other include an optical sheet in the same type and order, and implement the same optical characteristics with respect to the received incident light. I can.

The present invention can provide a PPG sensor package capable of effectively detecting a blood flow signal from a PPG signal even under a user's movement because the amount of light received through the light receiving unit can be increased, so that the PPG signal can be more accurately measured.

In addition, the present invention can provide a PPG sensor package that can be mounted in a wearable device to efficiently detect blood flow signals of a human body and easily manage health information.

1 is a cross-sectional view of a PPG sensor package according to an embodiment of the present invention.
2 is a layout diagram showing an arrangement of a light receiving unit and a light emitting unit in a PPG sensor according to a preferred embodiment of the present invention.
3 is a layout diagram showing an arrangement of a light receiving unit in a PPG sensor according to an embodiment of the present invention.
4A is a plan view of a PPG sensor package according to an embodiment of the present invention.
4B is a cross-sectional view of a PPG sensor package according to an embodiment of the present invention.
5A is a perspective view of a PPG sensor package according to an embodiment of the present invention.
5B is a perspective view of a PPG sensor package according to an embodiment of the present invention.
6 is a structural diagram of an optical film layer according to an embodiment of the present invention.
7 is a structural diagram of an optical film layer according to an embodiment of the present invention.
8 is a cross-sectional view of an optical sheet according to an embodiment of the present invention.
9 is a structural diagram of an optical film of a light emitting unit according to an embodiment of the present invention.
10 is a structural diagram of a light-receiving part optical film according to an embodiment of the present invention.
11 is a schematic diagram showing a heart rate detection process using a PPG sensor package according to an embodiment of the present invention.
12 is a cross-sectional view of a light receiving unit paired with each other according to an exemplary embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings, according to an embodiment of the present invention will be described in detail so that those of ordinary skill in the art can easily implement the present invention.

As described above, the conventional PPG sensor package has a limitation in that it is difficult to detect an accurate signal in a state in which a user's movement is present, so that effective heart rate detection is impossible. In addition, due to the low light emission and light-receiving efficiency of the PPG sensor, it is difficult to accurately and accurately measure the PPG signal.

In order to overcome the above-described limitations, the present invention provides a base substrate; A light-emitting unit coupled to an upper portion of the base substrate; A plurality of light-receiving units coupled to an upper portion of the base substrate and symmetrically disposed around the light-emitting unit; A light blocking member coupled to the base substrate, forming an accommodation space for accommodating the light emitting part and the light receiving part, and blocking light between the light emitting part and the light receiving part; A light-emitting part optical film coupled to the receiving space in which the light-emitting part is accommodated and including a diffusion sheet; And it is coupled to the receiving space in which the light receiving unit is accommodated, and provides a PPG sensor package including a light receiving unit optical film including a prism sheet.

Through this, the present invention can accurately and accurately measure the PPG signal, thereby enabling effective heart rate detection from the PPG signal even under the user's movement. In addition, the present invention is mounted in a wearable device to efficiently detect a human heartbeat detection signal, and thus has an advantage that can be usefully used in various wearable devices.

1 is a cross-sectional view of a PPG sensor package according to an embodiment of the present invention. Referring to FIG. 1, the present invention includes a light emitting unit 2 coupled to an upper portion of a base substrate 1 and a plurality of light receiving units 3 symmetrically disposed around the light emitting unit 2. In addition, the light blocking member 4 forms an accommodation space in which each of the light-emitting unit 2 and the light-receiving unit 3 are accommodated, and light is blocked between the light-emitting unit 2 and the light-receiving unit 3. In addition, the light-emitting part optical film 5 and the light-receiving part optical film 6 are respectively coupled to a receiving space in which the light-emitting part 2 is accommodated and a receiving space in which the light-receiving part 3 is accommodated.

First, the light emitting unit 2 functions to irradiate light onto a user's body by emitting light. The PPG sensor uses a change in the degree of absorption and reflection of light according to the change in the thickness of the blood vessel according to the heartbeat, and the light emitted from the light emitting surface of the light emitting unit 2 is irradiated to the user's body and detects the reflected light. Blood flow signal (heart rate) can be detected.

The light emitting unit 2 basically has a function of irradiating light in all directions, and the light irradiated from the light emitting unit 2 is reflected by the body (blood vessel, etc.) of the user who wants to detect a blood flow signal through the PPG sensor. do.

The light emitting unit 2 may use a light source capable of detecting a change in the thickness of a blood vessel by irradiating light, and preferably, a light emitting diode (LED), an organic light emitting diode (OLED), an infrared light emitting diode (Infrared Emitting Diode), and a laser It may be any one or more selected from the group consisting of diodes. Infrared or green light may be emitted through the light source. In the case of emitting infrared rays, the heart rate can be measured by measuring the amount of infrared absorption of red blood cells in blood vessels. In addition, when green light is emitted, red blood cells present in blood vessels tend to absorb green light, so the amount of green light absorption can be measured to measure the heart rate.

In addition, at least one light emitting unit 2 may be included in the PPG sensor package. When two or more light-emitting units 2 are included, the light-emitting units 2 may be spaced apart from each other. Preferably, it may be included in a smaller number than the light-receiving unit 3. In this case, the power supplied can be minimized, but the amount of light received through the light-receiving unit can be greatly increased, thereby improving the efficiency of the device in use.

In addition, the light emitting unit 2 may receive power from an electronic device including a PPG sensor package, and may be driven by the supplied power to emit light having a specific wavelength. In this case, the light-emitting part 2 has a space in which the light-emitting part 2 is accommodated by the light-shielding member 4 as described later in order to change the wavelength of the light signal to be irradiated as necessary, and the light-emitting part (2) It is possible to form an optical film 5 of the light emitting unit combined with the space in which it is accommodated.

Next, the light-receiving unit 3 receives the light signal by sensing the reflected light by irradiating the light emitted from the light-emitting unit 2 to the user's body, and generates a current signal for the received light signal. That is, the light-receiving unit 3 functions to receive an optical signal for the user's human body blood flow and generate a current signal for health information such as heart rate.

The light-receiving unit 3 is capable of receiving an optical signal by detecting the light reflected by the user's body, and may be used conventionally in the relevant technical field, but is preferably an organic photodiode. have. Organic photodiodes are devices that are based on organic materials and can replace photodetectors. When such an organic photodiode is used as the light receiving unit 3, light sensitivity of the electronic device may be improved. In addition, the organic photodiode has an advantage that it is lighter than inorganic materials and can be effectively used in various devices because it is inexpensive to produce. In addition, since organic materials can have sensitivity only in a specific wavelength range (ex; red light, green light, blue light, etc.) depending on the material of the organic material, the spectrum of the optical sensor is selected by selecting an appropriate material for the device to be used for the PPG sensor. Sensitivity can be adjusted.

Referring to FIG. 1, the light-receiving unit 3 includes a lower surface contacting the substrate 1 and a light-receiving surface for receiving an optical signal by sensing reflected light. Other surfaces of the light-receiving unit 3 other than the lower surface and the light-receiving surface may be light shielding surfaces. In this case, there is an effect of performing a light blocking function of preventing light emitted from the light emitting unit 2 from being directly incident on the light receiving unit 3. The light-shielding surface may be formed of various materials having a light-shielding function, but preferably, it may be formed of a black ink material or artificial rubber.

On the other hand, the plurality of light receiving portions 3 of the present invention are disposed surrounding the light emitting portion 2. According to a preferred embodiment of the present invention, the plurality of light-receiving units 3 are paired with each other, and any one of the light-receiving units 3 paired with each of the two light-receiving units 3 is centered on the light-emitting unit 2. As a result, it may be disposed to face the other light-receiving unit 3.

If the light-emitting part 2 is included as one, the plurality of light-receiving parts 3 may be disposed surrounding the light-emitting part 2. In addition, if a plurality of light-emitting units 2 are included, the distance between the plurality of light-emitting units 2 may be shorter than the distance between the light-emitting unit 2 and the light-receiving unit 3. When a plurality of light-receiving units 3 are arranged surrounding the light-emitting unit 2 as described above, since the light-receiving efficiency is remarkably improved, the intensity and accuracy of the detected signal are improved in comparison to the supplied power.

In addition, according to a preferred embodiment of the present invention, all of the plurality of light-receiving units 3 may be disposed to be spaced apart by the same distance from the light-emitting unit 2. In this case, since the light-receiving efficiency of each of the light-receiving units 3 is similar, there is an effect of improving accuracy and precision when detecting a PPG signal.

Specifically, FIG. 2 is a layout diagram showing an arrangement of a light receiving unit and a light emitting unit in a PPG sensor according to a preferred embodiment of the present invention. Referring to FIG. 2 (a), when the PPG sensor of the present invention includes one light-emitting part 2, a plurality of light-receiving parts 3 may be disposed around one light-emitting part 2 as the center. have. Further, referring to FIG. 2B, when the PPG sensor of the present invention includes a plurality of light emitting units 2, the plurality of light emitting units 2 may be disposed adjacent to each other. In addition, the plurality of light-receiving units 3 may be disposed surrounding the light-emitting units 2. Through this structure, light-receiving efficiency can be remarkably improved.

In addition, Figure 3 is a layout view showing the arrangement of the light receiving unit in the PPG sensor according to an embodiment of the present invention. Referring to FIG. 3, a plurality of light-receiving units are paired with each other, and any one of the light-receiving units paired with each of the two light-receiving units may be disposed to face the other light-receiving unit around the light-emitting unit. That is, it can be seen that the light-receiving part X and the light-receiving part X'are arranged to face each other around the light-emitting part 2, and the light-receiving part Y and the light-receiving part Y'are arranged to face each other around the light-emitting part 2.

Next, a light blocking member 4 that is coupled to the base substrate, forms an accommodation space in which the light emitting unit and the light receiving unit are accommodated, and blocks light between the light emitting unit and the light receiving unit, will be described. The light blocking member 4 has physical properties of blocking light, and may be made of a material having a property of blocking light.

The light blocking member 4 may be formed between each light emitting unit 2 and the light receiving unit 3 so as to block light between the light emitting unit 2 and the light receiving unit 3. In this case, an accommodation space in which the light-emitting unit 2 and the light-receiving unit 3 are accommodated may be formed by the light blocking member 4.

In addition, according to a preferred embodiment of the present invention, the accommodation space may be formed by being partitioned in the form of a partition wall by the light blocking member 4. That is, the light blocking member 4 is formed between each of the light emitting parts 2 and the light receiving parts 3, but is formed divided in the form of a partition wall, thereby providing an accommodation space in which each of the light emitting parts 2 and the light receiving parts 3 are accommodated. It can be formed as a separate space separated and spaced apart.

In this regard, referring to FIG. 1, a light blocking member 4 is formed between the light-emitting portion 2 and the light-receiving portion 3. In addition, the light blocking member 4 has a structure so as to surround the light-emitting unit 2 and the light-receiving unit 3 to form an accommodation space in which the light-emitting unit 2 and the light-receiving unit 3 are accommodated. Specifically, the receiving space is formed by being divided into a partition wall by the light blocking member 4, and the spaces in which the light emitting unit 2 and the light receiving unit 3 are accommodated form a separate space separated and spaced apart from each other. can confirm.

In this way, the optical film is coupled to the receiving space of the light-emitting unit 2 and the light-receiving unit 3 formed by the light blocking member 4.

Next, the light-emitting part optical film 5 coupled to the receiving space of the light-emitting part 2 and the light-receiving part optical film 6 combined with the receiving space of the light-receiving part 3 will be described. When the light-emitting part optical film 5 is combined with the light-emitting part 2 accommodation space and the light-receiving part optical film 6 is combined with the light-receiving part 3 accommodation space, a certain distance between the light-emitting part 2 and the light-receiving part 3 It is integrated in a state that maintains, so that the light wavelength can be appropriately converted as needed, and the diffusion and condensing functions can be improved. As described above, the optical films 5 and 6 are combined with the light emitting unit 2 receiving space and the light receiving unit 3 receiving space, so that the present invention can easily implement various optical characteristics, and accordingly, various electronic devices, especially miniaturized It can be usefully used in wearable devices.

According to a preferred embodiment of the present invention, the optical films 5 and 6 coupled to the receiving space are combined with at least a portion of the light blocking member 4 to form an upper portion of the light emitting unit 2 and the light receiving unit 3. Can be formed in That is, the light-emitting unit 2 and the light-receiving unit 3 are shielded from the light-emitting unit 2 and the light-receiving unit 3, and at least a part of the blocking member 4 forming an accommodation space and the optical films 5 and 6 are combined to each other, so that the light-emitting unit 2 and the light-receiving unit 3 The optical films 5 and 6 may be formed on the top of the. In this case,'the upper part of the light-emitting part 2 and the light-receiving part 3'means the upper side of the light-emitting part 2 and the upper side of the light-receiving part 3, and the upper surface of the light-emitting part 2 And the upper surface of the light-receiving part 3 is not meant.

Specifically, FIG. 4A is a plan view of a PPG sensor package according to a preferred embodiment of the present invention, and FIG. 4B is a cross-sectional view of a PPG sensor package according to a preferred embodiment of the present invention. Referring to FIG. 4A, in the present invention, a plurality of light-receiving parts 3 are symmetrically arranged around the light-emitting part 2. In addition, the light-emitting part optical film 5 is formed on the light-emitting part 2, the light-receiving part optical film 6 is formed on the light-receiving part 3, and the optical films 5 and 6 are It is combined with a part of the member 4. In addition, FIG. 4B is a cross-sectional view of the PPG sensor package taken along line A-A shown in FIG. 4A. Referring to FIG. 4B, a light-emitting portion 2 and a light-receiving portion 3 are formed on a base substrate 1, and the light-receiving portion 3 is symmetrically disposed around the light-emitting portion 2. In addition, the light blocking member 4 is also coupled on the base substrate 1 and forms an accommodation space in which the light-emitting unit 2 and the light-receiving unit 3 are accommodated, and the light-emitting unit 2 and the light-receiving unit 3 A light-shielding function is performed by forming a light-shielding wall between them. In addition, optical films 5 and 6 are formed on the light-emitting part 2 and the light-receiving part 3 by being combined with a part of the light blocking member 4. By forming such a structure, the light-emitting unit 2 and the light-receiving unit 3 of the present invention can be disposed at a certain distance from the optical films 5 and 6, and accordingly, the optical wavelength can be appropriately converted as needed. , Diffusion and condensing functions can be improved.

In addition, according to a preferred embodiment of the present invention, the upper surface of the light blocking member 4 may be positioned above the upper surfaces of the optical films 5 and 6. In this way, by adjusting the height and position between the light blocking member 4 and the optical films 5 and 6 in the PPG sensor package, the conversion of the light wavelength can be appropriately performed, and the light diffusion and condensing functions can be further improved. There is an effect.

Specifically, referring to FIGS. 1 and 4B, the upper surface 4 of the light blocking member is positioned above the upper surfaces of the optical films 5 and 6. As described above, it is preferable that the upper surface of the light blocking member 4 of the present invention is positioned above the upper surfaces of the optical films 5 and 6. If the upper surface of the light blocking member 4 is located at the same height as or below the upper surface of the optical films 5 and 6, there is a risk of damage to the optical films 5 and 6, and the light diffusion and condensing functions are slightly lowered. There is a risk of becoming.

As described above, the present invention may be formed in a specific structure, and according to a preferred embodiment of the present invention, the light-emitting unit optical film 5 and the light-receiving unit optical film 6 each have a light-emitting surface of the light-emitting unit 2 And spaced apart from the light-receiving surface of the light-receiving part 3. In this way, since the light-emitting unit 2 and the light-receiving unit 3 are arranged at a certain distance from the optical films 5 and 6, it is possible to appropriately convert the light wavelength as necessary, and the diffusion and condensing functions are improved. .

In this regard, FIGS. 5A and 5B are perspective views of a PPG sensor package according to an exemplary embodiment of the present invention. 5A is a perspective view of the PPG sensor package when the light blocking member 4 is shown, and FIG. 5B is a perspective view of the PPG sensor package when the light blocking member 4 is omitted. Referring to FIG. 5A, the light blocking member 4 blocks light between the light-emitting unit 2 and the light-receiving unit 3, and forms an accommodation space for the light-emitting unit 2 and the light-receiving unit 3. In addition, a part of the light blocking member 4 and the optical films 5 and 6 are combined. Referring to FIG. 5B, the present invention shows that the light emitting part 2 is formed on the base substrate 1, and the plurality of light receiving parts 3 are symmetrically arranged around the light emitting part 2. Able to know. In addition, the optical films 5 and 6 are disposed to be spaced apart from the light-emitting unit 2 and the light-receiving unit 3 at regular intervals, respectively. Through such an arrangement and structure, the present invention can further improve light diffusion and condensing functions, so that the PPG signal can be more accurately measured even under a user's movement.

Meanwhile, the light emitting part optical film 5 includes a diffusion sheet. The light emitting part optical film 5 may further include at least one optical sheet in addition to the diffusion sheet. In addition, the light-receiving part optical film 6 includes a prism sheet. The light receiving part optical film 6 may further include at least one optical sheet in addition to the prism sheet.

In this case, the optical sheet refers to a sheet capable of implementing or improving various optical properties, for example, a sheet capable of converting a light wavelength or improving diffusion or condensing efficiency. When the optical films 5 and 6 include two or more optical sheets, there is an effect of improving specific optical characteristics or implementing various optical characteristics at the same time.

When the optical films 5 and 6 include two or more optical sheets, it is preferable to form the optical films 5 and 6 in a laminated form of the optical sheets. In this case, all of the optical sheets to be laminated may be of different types, or some of them may be of the same type.

In this regard, FIGS. 6 and 7 are structural diagrams of an optical film layer according to a preferred embodiment of the present invention. First, FIG. 6 relates to optical films 5 and 6 in which optical sheets of L1 and L2 are formed in a two-layer structure. In this case, optical sheets having different L1 and L2 types may be stacked as shown in (a), and optical sheets having the same type of L1 and L2 may be stacked as shown in (b). When different types of optical sheets are stacked as shown in (a), it has the effect of simultaneously realizing various desired optical characteristics, and when the same types of optical sheets are stacked as shown in (b), specific optical characteristics are more effective. There is an effect that can be improved.

Next, FIG. 7 relates to optical films 5 and 6 in which optical sheets of L1, L2 and L3 are formed in a 3-layer structure. In this case, as in (a), optical sheets having different types of L1, L2, and L3 may be stacked, or optical sheets of the same type may be stacked with only some of the layers as shown in (b) and (c). In addition, optical sheets of the same type as shown in (b) may be stacked in succession, and optical sheets of the same type may be stacked in a form in which different types of optical sheets are inserted between the optical sheets of the same type as shown in (c).

As described above, in the present invention, optical sheets are stacked in multiple layers, but the optical films 5 and 6 can be formed by selecting the type and number of stacking optical sheets so that the PPG sensor can efficiently express the desired optical properties. have. In this case, a specific desired optical characteristic may be more efficiently implemented, or various optical characteristics may be simultaneously implemented, thereby making it possible to easily measure a PPG signal.

Meanwhile, according to a preferred embodiment of the present invention, the stacked sheets may be integrated to form the optical films 5 and 6 of the composite sheet. In this case, the meaning of being integrated may mean that the respective optical sheets are combined to be integrated into a single layer as a whole. As described above, since the optical film layer 4 of the present invention is integrated, various optical properties can be realized with a single member, mechanical strength can be improved, and handling is easy.

The integration of the optical films 5 and 6 may be performed through an optical bonding material and a bonding process, may be formed in a two-layer structure or more, and preferably may be formed in a 2 to 5-layer structure. When the optical film layer 4 is integrated within the range of the number of layers, there is an effect that the optical function can be simultaneously implemented in an optimized state.

In the optical films 5 and 6 of the present invention, the light emitting unit optical film 5 may further include a diffusion sheet and other optical properties that can be used ordinarily used in the relevant technical field. . In addition, the light-receiving part optical film 6 may further include a prism sheet that can implement or improve other optical properties, and that can be used conventionally in the relevant technical field.

Preferably, it may include any one or more sheets selected from the group consisting of a diffusion sheet, a prism sheet, a reflective sheet, and a microlens sheet, and more preferably, the light emitting part optical film 5 is a prism sheet or a microlens sheet. Any one or more of the sheets may be further included, and a composite sheet including a plurality of sheets in an integrated state, and the light receiving part optical film 6 further includes any one or more of a reflective sheet to a microlens sheet, It may be a composite sheet including a plurality of sheets in an integrated state.

These optical sheets have a diffusion function that diffuses light, a condensing function that improves luminance by refracting and condensing light, as well as a protective function that prevents the occurrence of scratches on other members close to the optical films 5 and 6. have.

The diffusion sheet can be uniformly transmitted to the entire surface of the light-emitting unit 2, that is, the light-transmitting layer that transmits light emitted from the light source. In addition, at the same time, high luminance can be expressed by improving light efficiency.

The diffusion sheet has a structure capable of uniformly transmitting light by diffusing light, and may be formed in various uneven embossing shapes. Preferably, the surface emitting or receiving light may be a three-dimensional protruding surface having a predetermined surface roughness. In this case, the diffusion sheet may have a structure in which beads of the same size are uniformly distributed on one surface of the transparent substrate to form a three-dimensional protruding surface. More preferably, the rear surface of the three-dimensional protruding surface may also be a three-dimensional protruding surface, and in this case, the diffusion sheet may have a structure in which beads are uniformly distributed on the other surface of the transparent substrate to form a three-dimensional protruding surface on both surfaces. In this case, it is preferable that the three-dimensional protruding surface forming the surface that emits or receives light has a larger average particle diameter of the bead than the other surface.

Specifically, FIG. 8 is a cross-sectional view of an optical sheet according to a preferred embodiment of the present invention. Figure 8 (a) shows a cross-section of the diffusion sheet 10 included in the light emitting unit 2 according to a preferred embodiment of the present invention. Beads are uniformly distributed on one side and the other side to form a three-dimensional protruding surface. You can see that it is done.

When the diffusion sheet is included in the optical film 5 of the light-emitting unit 2, the diffusion sheet can uniformly transmit light emitted from the light-emitting unit 2 to the entire surface of the light-transmitting layer. As a result, the electronic device to which the present invention is used can evenly transmit light to the body part of the user who is worn/used, and thus more accurate blood flow information can be obtained.

The prism sheet may diffuse light in various directions, such as horizontally or vertically, or condense light with a sharp drop in luminance in a specific direction through the prism. That is, when there is a need to condense light in a specific direction, it is possible to improve condensing efficiency by using a prism sheet.

The prism sheet may be formed to have a specific pattern with a structure capable of collecting scattered light. Preferably, it may have a linear arrangement pattern of a triangular pyramid or a square pyramid prism or a Fresnel pattern, more preferably, a linear arrangement pattern of a triangular pyramid prism. In the case of having a prism pattern as described above, the prism pattern having two inclined surfaces can improve light-condensing efficiency in a specific direction, and can enhance the luminance of an observed optical signal.

8 (b) is a cross-sectional view of a prism sheet 11 according to an embodiment of the present invention. Referring to FIG. 8B, it can be seen that the prism sheet 11 may be variously formed in a linear arrangement pattern or Fresnel pattern of triangular pyramids or square pyramids. That is, according to the present invention, by using a prism sheet having a pattern suitable for the type and characteristic of an electronic device using a PPG sensor, a specific optical characteristic can be efficiently implemented and a PPG signal can be more accurately detected.

When the prism sheet 11 is included in the light-receiving unit optical film 6, light signals reflected in various directions can be condensed in a specific direction, thereby improving light reception efficiency.

In addition, when the prism sheet 11 is included in the light emitting part optical film 5, the light diffused in an undesired direction among the emitted light may be condensed in a specific direction through the prism. In this case, since it is possible to improve the luminous efficiency compared to the power supply, there is an effect of efficiently detecting the PPG signal.

The reflective sheet may function to prevent light loss by reflecting emitted or incident light in a direction opposite to a light emitting surface or a light receiving surface. The reflective surface of the reflective sheet may be variously formed in a surface structure for performing even light reflection, and preferably may have a structure in which fine protrusions having a size of several to tens of µm are uniformly formed. Light scattered through such a structure can be reflected in a specific direction, thereby improving light efficiency, and through this, it is possible to efficiently detect a PPG signal.

8 (c) is a cross-sectional view of the reflective sheet 12 according to an embodiment of the present invention. Referring to FIG. 8C, the reflective sheet 12 may have uniform and uniform fine protrusions formed on the surface of the reflective sheet 12. Through this, it is possible to prevent light loss by reflecting incident light.

When the reflective sheet is included in the light emitting part optical film 5, it is possible to prevent the emitted light from being re-incident or the light signal to be received by the light receiving part 3 from being incident. In addition, when the prism sheet is included in the light-receiving part optical film 6, it is possible to prevent the light emitted from the light-emitting part 2 from being directly incident to the light-receiving part. Through this, light loss can be prevented, and luminous efficiency and light-receiving efficiency can be improved.

The microlens sheet may improve the luminance of light and at the same time perform a diffusion function of uniformly transmitting the light emitted from the light source to the entire surface of the light-transmitting layer. That is, the brightness enhancing function and the diffusion function can be simultaneously expressed.

The microlens sheet may have a structure in which hemispherical micro patterns are formed on a surface. In this case, since the light can be diffused in a direction perpendicular to the groove of the microlens pattern in one dimension, there is an effect of simultaneously having improved diffusion characteristics than that of a conventional prism sheet and improved luminance characteristics than that of a diffusion sheet.

8 (d) is a cross-sectional view of the microlens sheet 13 according to an embodiment of the present invention. Referring to FIG. 8 (d), hemispherical micropatterns having a uniform size are disposed on one surface of the microlens sheet 13 at uniform intervals. Since light is diffused in a direction perpendicular to the grooves of the patterns, the diffusion characteristic and the luminance characteristic can be realized at the same time.

When the microlens sheet 13 is included in the light-emitting part optical film 5, light emitted from the light-emitting part 2 can be uniformly transmitted to the entire surface of the light-transmitting layer. As a result, the electronic device to which the present invention is used can evenly transmit light to the body part of the user who is worn/used, and thus more accurate blood flow information can be obtained.

When the microlens sheet 13 is included in the light-receiving part optical film 6, light signals reflected in various directions can be condensed in a specific direction, thereby improving light reception efficiency.

The light emitting part optical film 5 of the present invention must include a diffusion sheet 10. In this case, since the light emitted from the light-emitting unit 2 can be evenly transmitted to the entire surface of the light-transmitting layer, there is an effect of evenly transmitting the light to the body part of the user who wants to measure a heartbeat signal.

In this regard, FIG. 9 is a structural diagram of the light emitting part optical film 5 according to a preferred embodiment of the present invention. Referring to FIG. 9, it can be seen that the light emitting part optical film 5 may be configured in various forms including the diffusion sheet 10.

Referring to FIG. 9A, a diffusion sheet 10 may be formed on the prism sheet 11. In this case, light emitted through the prism sheet 11 is condensed and then evenly diffused through the diffusion sheet 10 to the entire surface of the transmission layer, thereby improving luminous efficiency and light transmission efficiency to the user's body.

Referring to FIG. 9B, a microlens sheet 13 may be formed on the diffusion sheet 10. In this case, since the light evenly diffused through the diffusion sheet 10 can be diffused in a specific direction through the microlens sheet 13, the diffusion characteristic and the luminance characteristic can be simultaneously expressed.

Referring to FIG. 9C, the diffusion sheet 10-the microlens sheet 13-the reflective sheet 12 may be sequentially stacked and integrated. In this case, not only can the diffusion characteristic and the luminance characteristic be simultaneously expressed, but also the incident of emitted light and received light can be prevented, thereby minimizing light loss.

Referring to FIG. 9D, the microlens sheet 13-the diffusion sheet 10-the microlens sheet 13 may be sequentially stacked and integrated. In this case, both diffusion characteristics and luminance characteristics can be improved, and thus PPG signal detection efficiency can be remarkably improved.

In addition, the optical film 6 of the light-receiving part of the present invention must include a prism sheet 11. In this case, since the diffused or degraded light can be condensed, the light receiving unit 3 can receive the light signal reflected from the user's body by minimizing light loss.

In this regard, FIG. 10 is a structural diagram of an optical film 6 for a light receiving unit according to an exemplary embodiment of the present invention. Referring to FIG. 10, it can be seen that the light-receiving part optical film 6 may be configured in various forms including the prism sheet 11.

Referring to FIG. 10A, a prism sheet 11 may be formed on the diffusion sheet 10. In this case, light can be condensed in a specific direction with high light efficiency through the diffusion sheet 10 and the prism sheet 11, thereby improving the sensitivity and intensity of PPG signal detection.

Referring to FIG. 10B, a microlens sheet 13 may be formed on the prism sheet 11. In this case, the luminance and light efficiency of light can be remarkably improved, and thus the intensity of PPG signal detection is improved.

Referring to FIG. 10C, the prism sheet 11-the microlens sheet 13-the reflective sheet 12 may be sequentially stacked and integrated. In this case, it is possible to receive the optical signal more efficiently and at the same time, there is an effect of preventing light loss by reflecting light that is not a target of reception. Through this, the light-receiving efficiency can be remarkably improved.

Referring to FIG. 10D, the microlens sheet 13-the prism sheet 11-the microlens sheet 13 may be sequentially stacked and integrated. In this case, condensing efficiency can be remarkably improved, and thus the accuracy and intensity of PPG signal detection can be improved.

As described above, in the present invention, the type and stacking order of the optical sheet can be appropriately selected for the purpose of the PPG sensor package, and through this, it is possible to know the user's blood flow health information (heart rate) by receiving an optical signal from the user's body with excellent efficiency. have.

Specifically, Figure 11 is a schematic diagram showing a heart rate detection process using a PPG sensor package according to an embodiment of the present invention. Referring to FIG. 11, a process of detecting a user's heart rate using the electronic device 100 including the light emitting unit 2, the light receiving unit 3, the optical films 5 and 6, and the light transmitting layer 7 can be seen. First, (a) the light-emitting unit 2 may transmit uniformly diffused light to the light-transmitting layer 7. (b) Light emitted from the light-emitting unit 2 may pass through the light-transmitting layer 7 and irradiate the user's body. Through this, red blood cells in blood vessels absorb light of a specific wavelength such as infrared or green light, and other light is reflected. (c) The light-receiving unit 3 receives the light signal reflected from the user's body and detects the heartbeat signal by determining the amount of light absorbed.

In this way, since heartbeat detection using a PPG sensor package uses absorption and reflection of light, it is important to improve luminous efficiency and light-receiving efficiency. In the present invention, as described above, the luminous efficiency and light-receiving efficiency are remarkably improved, so that the amount of light irradiation to the user's body can be improved, and at the same time, the accuracy and intensity of the detected signal are excellent. In addition, since a signal can be easily detected even under a user's movement, it can be usefully used in various wearable devices.

Meanwhile, according to a preferred embodiment of the present invention, the light-receiving units 3 paired with each other may have corresponding optical characteristics. The meaning of having corresponding optical characteristics means that the same optical characteristics can be implemented with respect to incident light received through the light receiving unit.

Preferably, the optical films 6 of the light-receiving unit paired with each of the two may include an optical sheet in the same type and order, and may implement the same optical characteristics for incident light to be received. For example, referring to FIG. 3, the light-receiving part X and the light-receiving part X'may include the same type of optical sheet in the same order, but when the optical sheet on which the pattern is formed is included, the direction of the formed pattern is centered on the light-emitting part. It can be decided.

In this regard, FIG. 12 is a cross-sectional view of the light receiving unit 3 paired with each other according to an exemplary embodiment of the present invention. Referring to FIG. 12, the light-receiving part Z and the light-receiving part Z'include an optical film 6 including an optical sheet in the same type and order. The optical film 6 includes a prism sheet 11, and the pattern of the prism sheet 11 is formed in a direction corresponding to the light emitting portion 2 as the center. Through this, the light-receiving units paired with each other can implement the same optical characteristics with respect to the incident light received.

After all, the present invention is for measuring health information such as heart rate by measuring the amount of blood flowing through a blood vessel, and is for detecting an optical signal having excellent intensity, accuracy, and precision by improving luminous efficiency and light-receiving efficiency. As described above, since the luminous efficiency and light-receiving efficiency are remarkably improved with only a variety of simple structures as described above, the amount of light irradiation to the user's body can be improved, and at the same time, the accuracy and intensity of the detected signal are excellent. In addition, since a signal can be easily detected even under a user's movement, there is an advantage that it can be usefully used in various wearable devices.

Claims (10)

A base substrate;
At least one light-emitting unit coupled to a central portion of an upper portion of the base substrate;
At least a pair of light-receiving portions spaced apart from each other so as to surround the at least one light-emitting portion at an edge portion of an upper portion of the base substrate;
A light blocking member coupled to the base substrate, forming an accommodation space for accommodating the at least one light-emitting unit and the at least one pair of light-receiving units, and blocking light between the light-emitting unit and the light-receiving unit;
A light-emitting unit optical film including a diffusion sheet coupled to an accommodation space in which the at least one light-emitting unit is accommodated and uniformly transmits light emitted from the at least one light-emitting unit; And
A light-receiving part optical film including a prism sheet that is coupled to an accommodation space in which the at least one pair of light-receiving parts are accommodated, and condenses received light in a specific direction
Including,
Any one of the two light-receiving units forming a pair of light-receiving units is arranged to face the other light-receiving unit around the light-emitting unit.
PPG sensor package.
The method of claim 1,
The optical film coupled to the receiving space is a PPG sensor package, wherein the optical film is formed on each light emitting unit and each light receiving unit by combining at least a portion of the light blocking member.
The method of claim 1,
PPG sensor package, characterized in that the upper surface of the light blocking member is located above the upper surface of the optical film.
The method of claim 1,
The receiving space is a PPG sensor package, characterized in that the partition is formed in the form of a partition wall by a light blocking member.
The method of claim 1,
The light emitting part optical film further comprises at least one of a prism sheet to a microlens sheet, and a PPG sensor package, characterized in that it is a composite sheet including a plurality of sheets in an integrated state.
The method of claim 1,
The light-receiving unit optical film further includes any one or more of a reflective sheet to a microlens sheet, and a PPG sensor package, characterized in that it is a composite sheet including a plurality of sheets in an integrated state.
The method of claim 1,
The light-emitting part optical film and the light-receiving part optical film are formed to be spaced apart from the light-emitting surface of each light-emitting part and the light-receiving surface of each light-receiving part.
delete The method of claim 1,
All of the at least one pair of light-receiving units are disposed to be spaced apart by the same distance from the light-emitting unit.
The method of claim 1,
A PPG sensor package, characterized in that the light-receiving unit optical films coupled to the receiving space in which the at least one pair of light-receiving units are accommodated include optical sheets in the same type and order, and implement the same optical characteristics for incident light received.

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