Patent ID: 12213764

DETAILED DESCRIPTION

Hereinafter, some example embodiments are described in detail so that those skilled in the art can easily implement them. However, the actual applied structure may be implemented in various different forms and is not limited to the implementations described herein.

In the drawings, the thickness of layers, films, panels, regions, etc., are exaggerated for clarity. It will be understood that when an element such as a layer, film, region, or substrate is referred to as being “on” another element, it may be directly on the other element or intervening elements may also be present. In contrast, when an element is referred to as being “directly on” another element, there are no intervening elements present. It will further be understood that when an element is referred to as being “on” another element, it may be above or beneath or adjacent (e.g., horizontally adjacent) to the other element.

It will be understood that elements and/or properties thereof (e.g., structures, surfaces, directions, or the like), which may be referred to as being “perpendicular,” “parallel,” “coplanar,” or the like with regard to other elements and/or properties thereof (e.g., structures, surfaces, directions, or the like) may be “perpendicular,” “parallel,” “coplanar,” or the like or may be “substantially perpendicular,” “substantially parallel,” “substantially coplanar,” respectively, with regard to the other elements and/or properties thereof.

Elements and/or properties thereof (e.g., structures, surfaces, directions, or the like) that are “substantially perpendicular” with regard to other elements and/or properties thereof will be understood to be “perpendicular” with regard to the other elements and/or properties thereof within manufacturing tolerances and/or material tolerances and/or have a deviation in magnitude and/or angle from “perpendicular,” or the like with regard to the other elements and/or properties thereof that is equal to or less than 10% (e.g., a. tolerance of ±10%).

Elements and/or properties thereof (e.g., structures, surfaces, directions, or the like) that are “substantially parallel” with regard to other elements and/or properties thereof will be understood to be “parallel” with regard to the other elements and/or properties thereof within manufacturing tolerances and/or material tolerances and/or have a deviation in magnitude and/or angle from “parallel,” or the like with regard to the other elements and/or properties thereof that is equal to or less than 10% (e.g., a. tolerance of ±10%).

Elements and/or properties thereof (e.g., structures, surfaces, directions, or the like) that are “substantially coplanar” with regard to other elements and/or properties thereof will be understood to be “coplanar” with regard to the other elements and/or properties thereof within manufacturing tolerances and/or material tolerances and/or have a deviation in magnitude and/or angle from “coplanar,” or the like with regard to the other elements and/or properties thereof that is equal to or less than 10% (e.g., a. tolerance of ±10%).

It will be understood that elements and/or properties thereof may be recited herein as being “the same” or “equal” as other elements, and it will be further understood that elements and/or properties thereof recited herein as being “identical” to, “the same” as, or “equal” to other elements may be “identical” to, “the same” as, or “equal” to or “substantially identical” to, “substantially the same” as or “substantially equal” to the other elements and/or properties thereof. Elements and/or properties thereof that are “substantially identical” to, “substantially the same” as or “substantially equal” to other elements and/or properties thereof will be understood to include elements and/or properties thereof that are identical to, the same as, or equal to the other elements and/or properties thereof within manufacturing tolerances and/or material tolerances. Elements and/or properties thereof that are identical or substantially identical to and/or the same or substantially the same as other elements and/or properties thereof may be structurally the same or substantially the same, functionally the same or substantially the same, and/or compositionally the same or substantially the same.

It will be understood that elements and/or properties thereof described herein as being “substantially” the same and/or identical encompasses elements and/or properties thereof that have a relative difference in magnitude that is equal to or less than 10%. Further, regardless of whether elements and/or properties thereof are modified as “substantially,” it will be understood that these elements and/or properties thereof should be construed as including a manufacturing or operational tolerance (e.g., ±10%) around the stated elements and/or properties thereof.

When the terms “about” or “substantially” are used in this specification in connection with a numerical value, it is intended that the associated numerical value include a tolerance of ±10% around the stated numerical value. When ranges are specified, the range includes all values therebetween such as increments of 0.1%.

Hereinafter, the “wavelength spectrum” may mean an emission spectrum, an absorption spectrum, or a transmission spectrum.

Hereinafter, a bio imaging system according to some example embodiments will be described.

A bio imaging system is an imaging device capable of providing spatial distribution information such as a location, shape, size, and/or thickness of an internal tissue of the living body such as a blood vessel.

FIG.1is a plan view of a bio imaging system according to some example embodiments,FIG.2Ais a cross-sectional view taken along line II-II′ of the bio imaging system ofFIG.1, andFIGS.2B and2Care cross-sectional views showing examples of the light source shown inFIGS.1and2A.

The bio imaging system100according to some example embodiments includes a substrate110and a plurality of optoelectronic elements200.

The substrate110may be under the plurality of optoelectronic elements200to support the plurality of optoelectronic elements200. The substrate110may be in contact with a living body (e.g., skin) or close to a living body, and may have high light transmittance so that light emitted from the optoelectronic element200or flowing into the optoelectronic element200may pass. A light transmittance of the substrate110may be greater than or equal to about 70%, greater than or equal to about 75%, greater than or equal to about 80%, greater than or equal to about 85%, greater than or equal to about 90%, greater than or equal to about 95%, greater than or equal to about 97%, greater than or equal to about 98%, or greater than or equal to about 99%.

The substrate110may be a stretchable substrate. The stretchable substrate may respond flexibly to external forces or external movements such as twisting, pressing, and pulling, and may be easily restored to its original state.

The stretchable substrate may include a stretchable material such as an elastomer, and the stretchable material may include an organic elastomer, an organic/inorganic elastomer, an inorganic elastomer-like material, or a combination thereof. The organic elastomer or the organic/inorganic elastomer may be, for example, a substituted or unsubstituted polyorganosiloxane such as polydimethylsiloxane, an elastomer including substituted or unsubstituted butadiene moiety such as styrene-ethylene-butylene-styrene, an elastomer including a urethane moiety, an elastomer including an acrylic moiety, an elastomer including an olefin moiety, or a combination thereof, but is not limited thereto. The inorganic elastomer-like material may include a ceramic having elasticity, a solid metal, a liquid metal, or a combination thereof, but is not limited thereto.

The substrate110may include regions having different stiffness in relation to each other, for example, a rigid region110ahaving relatively high stiffness and a soft region110bhaving a relatively low stiffness. Herein, the stiffness indicates a degree of resistance to deformation when a force is applied from the outside. Relatively high stiffness means that the resistance to deformation is relatively large, so that deformation is small while relatively low stiffness means that the resistance to deformation is relatively small, so that the deformation is large.

The stiffness may be evaluated from an elastic modulus, and a high elastic modulus may mean high stiffness and a low elastic modulus may mean low stiffness. The elastic modulus may be, for example, a Young's modulus. A difference between elastic moduli of the rigid region110aand the soft region110bof the substrate110may be about 100 times or more, and the elastic modulus of the rigid region110amay be about 100 times higher than the elastic modulus of the soft region110b. The difference between the elastic modulus of the rigid region110aand the soft region110bmay be about 100 to 100,000 times within the above range, and the elastic modulus of the rigid region110amay be about 100 times to about 100,000 times higher than the elastic modulus of the soft region110b, but is not limited thereto. For example, the elastic modulus of the rigid region110amay be about 107Pa to about 1012Pa, and the elastic modulus of the soft region110bmay be greater than or equal to about 10 Pa and less than about 107Pa, but is not limited thereto.

Elongation rates of the rigid region110aand the soft region110bof the substrate110may be different due to the aforementioned difference in stiffness, and the elongation rate of the soft region110bmay be higher than the elongation rate of the rigid region110a. Herein, the elongation rate may be a percentage of the length change that is increased to a breaking point with respect to the initial length. For example, the elongation rate of the rigid region110aof the substrate110may be less than or equal to about 5%, within the range, about 0% to about 5%, about 0% to about 4%, about 0% to about 3%, about 0% to about 2%, about 0% to about 1%, about 0.5% to about 5%, about 0.5% to about 4%, about 0.5% to about 3%, about 0.5% to about 2%, or about 1% to about 2%. For example, the elongation rate of the soft region110bof the substrate110may be greater than or equal to about 10%, within the range, about 10% to about 300%, about 10% to about 200%, about 10% to about 100%, about 10% to about 90%, about 10% to about 80%, about 10% to about 70%, about 10% to about 60%, about 10% to about 50%, about 10% to about 40%, about 20% to about 70%, about 20% to about 60%, about 20% to about 50%, or about 20% to about 40%.

A plurality of rigid regions110aof the substrate110may have an island-shape separated from each other (e.g., isolated from direct contact with each other), and the optoelectronic elements200which are described later may be on each rigid region110aof the substrate110. The soft region110bof the substrate110may be a region other than the plurality of first regions110aand may be continuously connected thereto. The soft region110bof the substrate110may provide stretchability and due to its relatively low stiffness and high elongation rate, it may flexibly respond to external forces or external movements such as twisting and pulling, and may be easily restored to its original state.

A plurality of optoelectronic elements200are on the substrate110. The plurality of optoelectronic elements200may be regularly or randomly arranged on the substrate110, for example, may be arranged in parallel along an in-plane direction (e.g., x direction, y direction, or xy direction) of the substrate110. For example, the optoelectronic elements200may be arranged along rows and/or columns to form an array. For example, each optoelectronic element200may be on the rigid region110aof the substrate110.

In the drawings, the shape, size, and number of the optoelectronic elements200are illustrated as an example, but the shape, size, and number of the optoelectronic elements200may be variously changed. For example, the optoelectronic elements200may have a size (dimension) of several to hundreds of micrometers. For example, the optoelectronic elements200may each independently have a width, length, and thickness of greater than or equal to about 1 μm and less than 1000 μm, and within the range, may have a width, length, and thickness of about 10 μm to about 800 μm, about 10 μm to about 700 μm, about 10 μm to about 600 μm, or about 10 μm to about 500 μm, but is not limited thereto. For example, the number of optoelectronic elements200may be 4 or more, for example, 4 to 1000, 4 to 800, or 4 to 600, but is not limited thereto.

Each optoelectronic element200may be a light source210configured to emit light or a sensor220configured to absorb light and to convert the absorbed light into an electrical signal. For example, some of the plurality of optoelectronic elements200may be the light source210and some of the plurality of optoelectronic elements200may be the sensor220. The number (e.g., quantity) of light sources210and sensors220may be the same as or different from each other.

The light source210may supply light to internal tissues of a living body through the skin, and the light may belong to visible to infrared wavelength spectra, but is not limited thereto.

The light source210may include, for example, a light emitting element210-1such as an inorganic light emitting diode, an organic light emitting diode, or a micro light emitting diode. The light emitting element210-1may include, for example, a pair of electrodes211and212facing each other and a light emitting layer213between the pair of electrodes211and212.

At least one of the pair of electrodes211or212may be a light-transmitting electrode. For example, one of the pair of electrodes211or212may be a light-transmitting electrode and the other may be a reflective electrode. For example, an electrode close to the substrate110may be a light-transmitting electrode. One of the pair of electrodes211or212may be an anode and the other may be a cathode. For example, the pair of electrodes211and212may be stretchable electrodes, and the stretchable electrodes may include, for example, a stretchable conductor, or may have a stretchable shape such as a wavy, wrinkled, pop-up, or non-planar mesh shape.

The light emitting layer213may include an organic light emitting material, an inorganic light emitting material, a light emitting material such as quantum dot and/or perovskite, but is not limited thereto. The emission spectrum of the light emitting layer213may belong to a visible to infrared wavelength spectra, and may include, for example, a blue wavelength spectrum, a green wavelength spectrum, a red wavelength spectrum, a (near) infrared wavelength spectrum, or a combination thereof. For example, the light emitting layer213may be a stretchable light emitting layer. As an example, the light emitting element210-1may be a stretchable element.

The sensor220may be configured to absorb (e.g., selectively absorb) light supplied from the light source210and reflected by internal tissue of a living body (e.g., blood vessels), and may convert the absorbed light into an electrical signal.

The sensor220may include, for example, a light absorption element220-1such as an organic or inorganic diode. The light absorption element220-1may include, for example, a pair of electrodes221and222facing each other and a light absorption layer223between the pair of electrodes221and222. At least one of the pair of electrodes221or222may be a light-transmitting electrode. For example, one of the pair of electrodes221or222may be a light-transmitting electrode and the other may be a reflective electrode. For example, an electrode close to the substrate110may be a light-transmitting electrode. One of the pair of electrodes221or222may be an anode and the other may be a cathode. For example, the pair of electrodes221and222may be a stretchable electrode, and the stretchable electrode may include, for example, a stretchable conductor or have a stretchable shape such as a wavy shape, a corrugated shape, a pop-up shape, or a non-planar mesh shape.

The light absorption layer223may be a photoelectric conversion layer configured to absorb light of a particular (or, alternatively, predetermined) wavelength spectrum, and to convert the absorbed light into an electrical signal. Accordingly, a sensor220may be referred to as being configured to generate an electrical signal (which may be referred to herein as a signal) based on absorbing light, including absorbing light of a particular wavelength spectrum. The light absorption layer223may include, for example, an inorganic light absorbing semiconductor, an organic light absorbing semiconductor, and/or an organic-inorganic light absorbing semiconductor. For example, the inorganic light absorbing semiconductor, organic light absorbing semiconductor and/or organic-inorganic light absorbing semiconductor may be a p-type semiconductor and/or an n-type semiconductor forming a pn junction. The absorption spectrum of the light absorption layer223may belong to visible to infrared wavelength spectra, and may include, for example, a blue wavelength spectrum, a green wavelength spectrum, a red wavelength spectrum, a (near) infrared wavelength spectrum, or a combination thereof. For example, the light absorption layer223may be a stretchable light absorption layer. For example, the light absorption element220-1may be a stretchable element.

At least one of the light source210or the sensor220may be configured to emit or absorb light of different wavelength spectra. For example, the bio imaging system100may include a light source210that is configured to emit light of different wavelength spectra, a sensor220that is configured to absorb light of different wavelength spectra, or both a light source210that is configured to emit light of different wavelength spectra and a sensor220that is configured to absorb light of different wavelength spectra.

The bio imaging system100(and/or an electronic device in which the bio imaging system100is included) may be configured to combine a plurality of images obtained by light of different wavelength spectra to obtain a three-dimensional image of an internal tissue of a living body (e.g., blood vessels). For example, as shown, the bio imaging system100may include a controller101that is communicatively and/or electrically coupled to the light source210and the sensor220via a conductive path, including one or more conductive materials, conductive layers, wires, or the like. The controller101may be configured to control operation of the light source210and/or the sensor220(e.g., based on generating and transmitting signals to the light source210and/or sensor220via a conductive path, wire, or the like) to cause the light source210to emit light and/or to cause the sensor220to absorb light. The sensor220may be configured to generate signals based on absorbing light, and the bio imaging system100may be configured to transmit such signals from the sensor220to the controller101(e.g., via a conductive line, wire, bus, or the like). The sensor220may be configured to generate signals based on absorbing light, and the bio imaging system100may be configured to communicate such signals to the controller101, independently of any control of the sensor220by the controller101. The controller101may be configured to process the signals to generate (e.g., obtain) one or more images, such that the controller101of the bio imaging system100may be configured to obtain (e.g., generate) images based on light of various (e.g., different) wavelength spectra (e.g., based on the sensor220generating various signals based on light of various wavelength spectra being absorbed by one or more portions of the sensor220, and said signals being received and processed by the controller101to generate the images).

It will be understood that the controller101may be implemented by one or more instances of processing circuitry as described herein (e.g., as described with reference toFIG.34) and may include, may be included in, and/or may be implemented by one or more devices as described herein, (e.g., the controller101may include processor1320ofFIG.34and memory1330ofFIG.34, and/or any functionality of the bio imaging system100and/or the controller101may be implemented based on processor1320ofFIG.34executing a program of instructions stored in memory1330ofFIG.34).

Where the bio imaging system100is described herein as performing an operation and/or being configured to perform an operation (e.g., combining a plurality of images obtained based on the light of different wavelength spectra to obtain a three-dimensional image of an internal tissue of a living body), it will be understood that the bio imaging system100may include one or more instances of processing circuitry (e.g., a processor executing a program of instructions stored in a memory to implement the functionality of the controller101) that are configured to operate to cause the bio imaging system100to perform the operation and/or to be configured to perform the operation. Such operations that the controller101may be configured to perform (e.g., based on a processor such as a CPU of the controller101executing a program of instructions stored in a memory such as a SSD of the controller101) may include generating signals to control operation of the light source210, for example to cause the light source210(e.g., one or more light emitting elements of the light source) to emit light. Such operations that the controller101may be configured to perform may include processing signals generated by the sensor220, for example one or more sensors of the sensor220, based on the sensor220absorbing light, and received at the controller101from the sensor220to generate (e.g., obtain) one or more images, including images that are obtained based on the light of different wavelength spectra. Such operations that the controller101may be configured to perform may include processing signals and/or images to extract differences between a plurality of images to obtain a plurality of extracted images of an internal tissue of a living body according to a depth from skin surface. Such operations that the controller101may be configured to perform may include processing a plurality of extracted images to combine the plurality of extracted images to obtain a three-dimensional image of the internal tissue of the living body. Such operations that the controller101may be configured to perform may include controlling the light source210and/or the sensor220to obtain a correction image from a portion of the light source210or a portion of the sensor220, correcting the plurality of extracted images using the correction image; obtaining the three-dimensional image based on the corrected extracted images.

In some example embodiments, the controller101may be part of a separate bio imaging system that is external to the bio imaging system100, where the controller101may control at least one of the light source210or the sensor220and may be configured to receive signals from the sensor220based on the sensor220absorbing light, where the controller101may process the signals to obtain images and to perform any methods as described herein with regard to obtaining and/or extracting images, including three-dimensional images.

The light source210may include a plurality of light sources configured to emit light of different wavelength spectra in relation to each other.

The sensor220may include a plurality of sensors configured to absorb light of different wavelength spectra in relation to each other.

The light source210may include a plurality of light sources configured to emit light of different wavelength spectra in relation to each other, and the sensor220may include a plurality of sensors configured to absorb light of different wavelength spectra in relation to each other.

Hereinafter, examples of the bio imaging system100shown inFIGS.1,2A,2B, and2Cwill be described with reference toFIGS.3to6B.

FIG.3is a plan view showing an example of the bio imaging system shown inFIGS.1and2A to2C,FIG.4is a cross-sectional view taken along line IV-IV′ of an example of the bio imaging system ofFIG.3,FIGS.5A and5Bare cross-sectional views showing examples of the light source shown inFIGS.3and4, andFIGS.6A and6Bare graphs showing an example of a wavelength spectrum of a light source and a sensor of the bio imaging system shown inFIGS.3and4.

Referring toFIGS.3and4, a bio imaging system100according to some example embodiments includes a substrate110; a plurality of light sources210arranged on the substrate110and configured to emit light of different wavelength spectra in relation to each other; and a plurality of sensors220arranged on the substrate110. As described above, the plurality of light sources210and the plurality of sensors220may be on the rigid region110aof the substrate110.

The light source210includes a first light source210a, a second light source210b, and a third light source210cthat are separated from each other (e.g., isolated from direct contact with each other). The light source210may additionally include an nthlight source210nin addition to the first light source210a, the second light source210b, and the third light source210c, where n may be an integer of 4 to 10. The nthlight source210ndoes not mean one light source, but an nthlight source. For example, when n is 7, the light source210may further include fourth, fifth, sixth, and seventh light sources in addition to the first light source210a, second light source210b, and third light source210c. The nthlight source210nmay be omitted.

As shown, the first light source210a, the second light source210b, the third light source210c, and the nthlight source210nare arranged in parallel (e.g., may extend in a linear sequence) along an in-plane direction of the substrate110(e.g., x direction, y direction, or xy direction) and light of different emission spectra in relation to each other within the visible to infrared wavelength spectra may be emitted. Restated, the first light source210a, the second light source210b, the third light source210c, and the nthlight source210nmay be configured to emit light of different emission spectra. Said different emission spectra may be within the visible to infrared wavelength spectra. For example, the first light source210a, the second light source210b, the third light source210c, and the nthlight source210nmay be configured to each emit light of different wavelength spectra in relation to each other within a wavelength range (e.g., wavelength spectrum) of about 380 nm to about 3 μm and a plurality of images obtained by light of different emission spectra in relation to each other may be combined to obtain a three-dimensional image of an internal tissue of a living body.

It will be understood, as described herein, that an in-plane direction of the substrate110(e.g., x direction, y direction, or xy direction) may extend in parallel to an upper surface of the substrate110and thus may be referred to interchangeably as a direction extending in parallel to the upper surface of the substrate110. Additionally, a direction extending perpendicular to the in-plane direction (e.g., the z direction, which extends perpendicular to the x direction, y direction, or xy direction) may be referred to interchangeably herein as a direction extending perpendicular to the upper surface of the substrate110.

The first light source210a, the second light source210b, the third light source210c, and the nthlight source210nmay respectively include a first light emitting element210a-1, a second light emitting element210b-1, a third light emitting element210c-1, and an nthlight emitting element210n-1which are configured to emit light of different emission spectra in relation to each other. That is, the first light source210amay include the first light emitting element210a-1, the second light source210bmay include the second light emitting element210b-1, the third light source210cmay include the third light emitting element210c-1, and the nthlight source210nmay include the nthlight emitting element210n-1. Each of the first, second, third, and nthlight emitting elements210a-1,210b-1,210c-1, and210n-1may be an inorganic light emitting diode, an organic light emitting diode, or a micro light emitting diode. The light emitting characteristics of the first, second, third and nthlight sources210a,210b,210c, and210nmay be the same or substantially the same as the light emission characteristics of the first, second, third, and nthlight emitting elements210a-1,210b-1,210c-1, and210n-1.

Referring toFIGS.5A to5D, the first light emitting element210a-1may include a pair of electrodes211aand212afacing each other and a light emitting layer213abetween a pair of electrodes211aand212a, the second light emitting element210b-1may include a pair of electrodes211band212bfacing each other and a light emitting layer213bbetween the pair of electrodes211band212b, the third light emitting element210c-1may include a pair of electrodes211cand212cfacing each other and a light emitting layer213cbetween the pair of electrodes211cand212c, and the nthlight emitting element210n-1may include a pair of electrodes211nand212nfacing each other and a light emitting layer213nbetween the pair of electrodes211nand212n. The descriptions of the pair of electrodes211and212and the light emitting layer213are as described above.

The emission spectra of the light emitted from the first light emitting element210a-1, the second light emitting element210b-1, the third light emitting element210c-1, and the nthlight emitting element210n-1may be determined by the light emitting layers213a,213b,213c, and213n, and the light emitting layers213a,213b,213c, and213nmay be configured to emit light of different emission spectra in relation to each other. For example, each of the first light emitting element210a-1, the second light emitting element210b-1, the third light emitting element210c-1, and the nthlight emitting element210n-1may be configured to emit light of a first emission spectrum having a first maximum emission wavelength λE1,max, a second emission spectrum having a second maximum emission wavelength λE2,max, a third emission spectrum having a third maximum emission wavelength λE3,max, and an nthemission spectrum having an nthmaximum emission wavelength λEn,max, wherein the first maximum emission wavelength λE1,max, the second maximum emission wavelength λE2,max, the third maximum emission wavelength λE3,max, and the nthmaximum emission wavelength λEn,maxmay be different from each other.

The sensor220may be adjacent to at least a portion of the first, second, third, and nthlight sources210a,210b,210c, and210n, and as shown inFIG.2C, the sensor220may include a light absorption element220-1including a pair of electrodes221and222facing each other and a light absorption layer223between the pair of electrodes221and222. The light absorption characteristics of the sensor220may be the same or substantially the same as the absorption characteristics of the light absorption layer223, and the absorption spectrum of the sensor220may include light of all emission spectra emitted from the light source210.

Referring toFIGS.6A and6BwithFIGS.5A to5D, the first light emitting element210a-1may be configured to emit light of a first emission spectrum SPE1having a first maximum emission wavelength λE1,max, the second light emitting element210b-1may be configured to emit light of a second emission spectrum SPE2having a second maximum emission wavelength λE2,max, the third light emitting element210c-1may be configured to emit light of a third emission spectrum SPE3having a third maximum emission wavelength λE3,max, and the nthlight emitting element210n-1may be configured to emit light of an emission spectrum SPEnhaving an nthmaximum emission wavelength λEn,max. That is, the light emitting layer213amay be configured to emit light of the first emission spectrum SPE1having the first maximum emission wavelength λE1,max, the light emitting layer213bmay be configured to emit light of the second emission spectrum SPE2having the second maximum emission wavelength λE2,max, the light emitting layer213cmay be configured to emit light of the third emission spectrum SPE3having the third maximum emission wavelength λE3,max, and the light emitting layer213nmay be configured to emit light of the emission spectrum having the nthmaximum emission wavelength λEn,max.

The second maximum emission wavelength λE2,maxmay be a longer wavelength than the first maximum emission wavelength λE1,max, the third maximum emission wavelength λE3,maxmay be a longer wavelength than the second maximum emission wavelength λE2,max, and the nthmaximum emission wavelength λEn,maxmay be a longer wavelength than the third maximum emission wavelength λE3,max. The first maximum emission wavelength λE1,max, the second maximum emission wavelength λE2,max, the third maximum emission wavelength λE3,max, and the nthmaximum emission wavelength λEn,maxmay be separated by a particular (or, alternatively, predetermined) interval. For example, each difference between two adjacent wavelengths of the first maximum emission wavelength λE1,max, the second maximum emission wavelength λE2,max, the third maximum emission wavelength λE3,max, and the nthmaximum emission wavelength λEn,maxmay be for example greater than or equal to about 10 nm, within the above range, greater than or equal to about 15 nm, greater than or equal to about 20 nm, greater than or equal to about 30 nm, greater than or equal to about 40 nm, or greater than or equal to about 50 nm, within the above range, about 10 nm to about 500 nm, about 15 nm to about 500 nm, about 20 nm to about 500 nm, about 30 nm to about 500 nm, about 40 nm to about 500 nm, about 50 nm to about 500 nm, about 10 nm to about 300 nm, about 15 nm to about 300 nm, about 20 nm to about 300 nm, about 30 nm to about 300 nm, about 40 nm to about 300 nm or about 50 nm to about 300 nm.

The first maximum emission wavelength λE1,max, the second maximum emission wavelength λE2,max, the third maximum emission wavelength λE3,max, and the nthmaximum emission wavelength λEn,maxmay belong to a visible to infrared wavelength spectra, and may be for example independently within about 380 nm to about 3 μm, about 400 nm to about 2 μm, about 450 nm to about 1500 nm, about 470 nm to about 1150 nm, about 480 nm to about 1100 nm, about 500 nm to about 1000 nm, about 550 nm to about 1000 nm, or about 600 nm to about 1000 nm. For example, the first maximum emission wavelength λE1,max, the second maximum emission wavelength λE2,max, the third maximum emission wavelength λE3,max, and the nthmaximum emission wavelength λEn,maxmay each independently belong to one of a blue wavelength spectrum, a green wavelength spectrum, a red wavelength spectrum, or a (near) infrared wavelength spectrum, wherein the blue wavelength spectrum may be greater than or equal to about 400 nm and less than about 500 nm, the green wavelength spectrum may be greater than or equal to about 500 nm and less than or equal to about 600 nm, the red wavelength spectrum may be greater than about 600 nm and less than or equal to about 700 nm, and the (near) infrared wavelength spectrum may be greater than about 700 nm and less than or equal to about 3000 nm.

The full width at half maximum (FWHM) of the first, second, third, and nthemission spectra SPE1, SPE2, SPE3, and SPEnmay be, for example, less than or equal to about 300 nm, and within the above range, about 10 nm to about 300 nm, about 30 nm to about 250 nm, or about 50 nm to about 200 nm.

Since the sensor220may detect light emitted from the first, second, third, and nthlight sources210a,210b,210c, and210nand reflected by internal tissue of a living body (e.g., blood vessels), the absorption spectrum SPA of the sensor220may include light of all wavelength spectra emitted from the first, second, third, and nthlight sources210a,210b,210c, and210n.

For example, the absorption spectrum of light detected by the sensor220may include all emission spectra of the first to nthlight sources210a,210b,210c, and210n, and may be for example, within about 380 nm to about 3 μm, about 400 nm to about 2 μm, about 450 nm to about 1500 nm, about 470 nm to about 1150 nm, about 480 nm to about 1100 nm, about 500 nm to about 1000 nm, about 550 nm to about 1000 nm, or about 600 nm to about 1000 nm. For example, when the first, second, and third light sources210a,210b, and210cemit light of a blue wavelength spectrum, a green wavelength spectrum and a red wavelength spectrum, respectively, the sensor220may detect light in a white wavelength spectrum including the blue wavelength spectrum, green wavelength spectrum, and red wavelength spectrum.

In the bio imaging system100according to some example embodiments, the plurality of light sources210a,210b,210c, and210nconfigured to emit light of different emission spectra in relation to each other may provide a plurality of images of an internal tissue of a living body according to the depth direction form the skin surface by using the difference in the penetration depth of light according to the wavelength (e.g., based on the sensor220absorbing light due to the plurality of light sources210a,210b,210c, and210nemitting light of different emission spectra in relation to each other and generating signals based on such absorbance that are processed by controller101to generate the plurality of images, for example based on controller101processing signals generated due to the sensor220absorbing light within a particular wavelength spectrum to generate a particular image associated with the particular wavelength spectrum). Such the plurality of images are combined (e.g., by the controller101) to obtain information (e.g., properties of the internal tissues of the living body) such as a location, shape, size, and/or thickness of the internal tissues of the living body (e.g., blood vessels), and this information may be used to obtain spatial information of the internal tissues of the living body. In addition, this spatial information may be separated and/or extracted to effectively obtain information of the internal tissues of the living body present at a specific depth from the skin surface.

Specifically, when the skin is irradiated with light, the penetration depth of the light from the skin surface is different depending on a wavelength spectrum, and in general, light of a long wavelength spectrum may penetrate deeper than light of a short wavelength spectrum. On the other hand, since the light of the long wavelength spectrum may also be scattered, while it passes several tissues along the depth direction from the skin surface, information obtained from light of a particular (or, alternatively, predetermined) wavelength may not images of the internal tissues present at the maximum penetration depth but images of all the internal tissues of the living body within a penetration depth of the light. Accordingly, clear images of the internal tissues of the living body such as blood vessels present at a particular depth may be difficult to selectively obtain.

In some example embodiments, a plurality of light sources210a,210b,210c, and210nconfigured to emit light of different emission spectra and the sensor220configured to absorb the light reflected by the internal tissues of the living body by being irradiated from the plurality of light sources210a,210b,210c, and210nare arranged in the form of an array, and thereby different image information according to the penetration depth of light are combined to separate and/or extract image information of an internal body tissue along a depth direction from the skin surface, and to obtain image information of an internal tissue of a living body located at a specific depth.

For example, in the bio imaging system100shown inFIGS.3to6B, when the first light source210ais configured to emit light of the first emission spectrum SPE1having a first maximum emission wavelength λE1,max, which is a relatively short wavelength, the second light source210bis configured to emit light of the second emission spectrum SPE2having a second maximum emission wavelength λE2,maxthat is longer than the first maximum emission wavelength λE1,max, and the third light source210cis configured to emit light of the third emission spectrum SPE3having a third maximum emission wavelength λE3,maxthat is longer than the second maximum emission wavelength λE2,max, the light of the first emission spectrum SPE1, second emission spectrum SPE2and third emission spectrum SPE3have different penetration depth of light from the skin surface, respectively, the light of the first emission spectrum SPE1, second emission spectrum SPE2and third emission spectrum SPE3may pass through the skin, transmit by each maximum penetration depth, and be reflected by an internal tissue of a living body (e.g., blood vessels), and the reflected light may be absorbed and detected for each wavelength by the sensor220.

At this time, no matter what distribution of the penetration depth of the light of the first emission spectrum SPE1, the second emission spectrum SPE2and the third emission spectrum SPE3from the skin surface, the image obtained from irradiation of the third light source210cconfigured to emit light of a relatively long wavelength emission spectrum may be an image at a position deeper than the image obtained from irradiation of the second light source210bconfigured to emit light of a relatively short wavelength emission spectrum, and the image obtained from irradiation of the second light source210bconfigured to emit light of a relatively long wavelength emission spectrum may be an image at a position deeper than the image obtained from irradiation of the first light source210aconfigured to emit light of a relatively short wavelength emission spectrum. Therefore, by extracting the difference between the image obtained from the irradiation of the third light source210cand the image obtained from the irradiation of the second light source210b, image information at a depth at which only light of the third emission spectrum SPE3penetrates may be obtained, and by extracting the difference between the image obtained from the irradiation of the second light source210band the image obtained from the irradiation of the first light source210a, image information at a depth at which only light of the second emission spectrum SPE2penetrates may be obtained. Accordingly, it is possible to effectively obtain image information of an internal tissue of a living body located at a specific depth from the skin surface.

In this way, the differences between (n−1) images obtained by selective irradiation of any two light sources among n light sources210a,210b,210c, and210nconfigured to emit light of different emission spectra in relation to each other are extracted and combined, and thereby, spatial information may be secured in the depth direction. The more the number of light sources, the more accurate spatial information may be secured in the depth direction.

One example of a bio imaging method using the aforementioned bio imaging system100may include fixing the bio imaging system100on the skin S of a living body; radiating light into the skin S by turning on the light source210(e.g., causing the light source210to emit light to irradiate the skin); and absorbing light passing the skin S and scattered and reflected by the internal tissues of the living body such as blood vessel BV by the sensor220(e.g., causing the sensor220to absorb light scattered and reflected by the internal tissue of the living body through the skin S) to obtain a plurality of images by the light of a wavelength spectrum different from each other (e.g., based on light of different wavelength spectra). The method may further include extracting the plurality of images of the internal tissues of the living body such as the blood vessel BV depending on a depth from the surface of the skin S (e.g., extracting differences between the obtained plurality of images to obtain a plurality of extracted images of the internal tissue of the living body according to a depth from the skin S surface); and combining the plurality of extracted images of the internal tissues of the living body such as the blood vessel BV to obtain a three-dimensional image of the internal tissues of the living body. The light source210may include first, second, third, and nthlight sources210a,210b,210c, and210nconfigured to emit light of different emission spectra within visible to infrared wavelength spectra. The turning on of the light source210may include sequentially turning on the first, second, third, and nthlight sources210a,210b,210c, and210n(e.g., causing the first, second, third, and nthlight sources210a,210b,210c, and210nto sequentially emit light).

FIG.25is a schematic view showing an example of a method of obtaining image information of an internal tissue of a living body using a bio imaging system according to some example embodiments,FIG.26is a schematic cross-sectional view showing an example of a method of obtaining image information of an internal tissue of a living body using the bio imaging systems ofFIGS.3to6B, andFIGS.27A and27Bare schematic views of obtaining a three-dimensional image by (e.g., based on) combining a plurality of images obtained by the methods ofFIGS.25and26.

As shown inFIG.25, by fixing (attaching) the aforementioned bio imaging system100to the skin S, image information of internal tissue of a living body such as blood vessels BV may be obtained. Herein, as described above, when the first, second, third, and nthlight sources210a,210b,210c, and210nof the bio imaging system100are sequentially turned on to irradiate light to the skin S, the penetration depth from the skin surface S1may vary according to the emission spectrum of light, and light of a relatively long wavelength may penetrate deeper than light of a relatively short wavelength.

Accordingly, referring toFIGS.26,27A, and27B, the depths D1, D2, and D3at which the light irradiated from the first, second and third light sources210a,210b, and210cpenetrate according to the wavelength have a particular (or, alternatively, predetermined) distribution, the light is reflected by different depths D1, D2, and D3, and a plurality of planar (two-dimensional) images M1, M2, and M3according to the depths D1, D2, and D3of an internal tissue of a living body such as blood vessels BV depending on the wavelength may be obtained. For example, as described above, when among the first, second, and third light sources210a,210b, and210c, the first light source210ais configured to emit light of the first emission spectrum SPE1having the relatively shortest wavelength, and the third light source210cis configured to emit light of the emission spectrum SPE3of the relatively longest wavelength, signals obtained by irradiation of light of the first to third emission spectrum SPE1, SPE2, and SPE3may provide images M1, M2, and M3from a relatively close depth D1to the deepest depth D3from the skin surface S1, sequentially. Based on these images M1, M2, and M3, the image difference according to each depth D1, D2, and D3is extracted, and the lowest point, the middle point, and the highest point of the blood vessel BV are specified to obtain a three-dimensional image of the blood vessel BV. For example, differences between the images M1, M2, and M3may be extracted based on extracting a first image of an internal tissue of the living body located at a first depth D1from the skin S surface based on a difference between an image M2obtained based on turning on the second light source210band an image M1obtained based on turning on the first light source210a, and extracting a second image of the internal tissue of the living body located at a second depth D2deeper than the first depth D1based on a difference between an image M3obtained based on turning on the third light source210cand the image M2obtained based on turning on the second light source210b.

Spatial information such as the location, shape, size and/or thickness of the blood vessel BV may be confirmed from the three-dimensional image of the blood vessel BV.

FIG.28is a schematic view showing an example of a method of obtaining image information of an internal tissue of a living body using a bio imaging system according to some example embodiments, andFIG.29is a schematic cross-sectional view showing an example of a method of obtaining image information of an internal tissue of a living body using the bio imaging system ofFIGS.3to6B.

In the present example, when a plurality of blood vessels BV1and BV2are located to be overlapped with each other in the depth direction, an image of a blood vessel BV located at a specific depth may be obtained by separating the images of the plurality of blood vessels BV and extracting the difference.

That is, the depths D1, D2, and D3at which the light irradiated from the first, second, and third light sources210a,210b, and210cpenetrate according to the wavelength have a particular (or, alternatively, predetermined) distribution, and a plurality of images of internal tissue of a living body such as blood vessels BV1and BV2reflected by different depths according to wavelength may be obtained. Image information obtained from light of the first to third emission spectrum SPE1, SPE2, and SPE3may include spatial information from a relatively close depth D1to the deepest depth D3from the skin surface S1, respectively, and it is possible not only to obtain a three-dimensional image of each blood vessel BV1and BV2, by extracting the difference between the plurality of images and specifying the lowest point, the middle point, and the highest point of each blood vessel BV1and BV2, but also to obtain a clear image of the blood vessel BV2without reducing the resolution caused by the blood vessel BV1, by extracting the difference between the image obtained from the blood vessel BV2and the image obtained from the blood vessel BV1. Therefore, when the plurality of blood vessels BV1and BV2are located in the depth direction from the skin surface S1, spatial information of the internal tissues of the living body may be effectively checked in this manner. Here, an example in which two blood vessels BV1and BV2are located in the depth direction has been described, but a case in which n blood vessels are located in the depth direction may also be described.

Meanwhile, the bio imaging method may further include obtaining a correction image before (e.g., prior to) obtaining the aforementioned three-dimensional image. The correction image may be for excluding an influence of the light characteristics (e.g., scattering and/or absorption) of the skin caused by differences in skin color and thickness of subcutaneous tissue for each individual, and may be obtained based on, for example, a point spread function. For example, the correction image may be obtained by turning on only some of the light sources210of the first position (specific position) of the bio imaging system100to obtain an image according to the wavelength spectrum of the first position corresponding to the turned on some of the light sources210, turning on only some of the light sources210at the second position (specific position) of the bio imaging system100to obtain an image according to the wavelength spectrum of the second position corresponding to the turned on some light sources210, and in this way, turning on only some of the light sources210at the nthposition to obtain an image according to the wavelength spectrum of the nthposition corresponding to the turned-on some of the light sources210. The correction image may be applied to the plurality of extracted images to correct the plurality of extracted images. The corrected extracted images may then be combined to obtain the three-dimensional image. By correcting the aforementioned plurality of extracted images using the correction image, the effect of the optical characteristics of the skin may be excluded to obtain a clear three-dimensional image. Accordingly, a three-dimensional image of the internal tissue of the living body may be obtained based on combining the plurality of extracted images.

Hereinafter, another example of the bio imaging system100shown inFIGS.1to2Bwill be described with reference toFIG.7along withFIGS.3to6B.

FIG.7is a cross-sectional view of another example of the bio imaging system ofFIG.3taken along line IV-IV′, andFIGS.8A,8B,8C, and8Dare graphs showing an example of a wavelength spectrum of a light source and a sensor of the bio imaging system shown inFIGS.3and7.

Referring toFIG.7, a bio imaging system100according to some example embodiments includes a substrate110; a plurality of light sources210arranged on the substrate110; and a plurality of sensors220arranged on the substrate110, and the light source210is separated from each other and includes a first light source210a, a second light source210b, and a third light source210cand optionally an nthlight source210nwhich are configured to emit light of different wavelength spectrum, like the aforementioned example.

However, in the bio imaging system100according to the present example, the light source210may include first, second, third, and nthlight sources210a,210b,210c, and210nthat include a first light emitting element210a-1, a second light emitting element210b-1, a third light emitting element210c-1, and an nthlight emitting element210n-1which each is configured to emit light of a common emission spectrum (e.g., a same emission spectrum), and each of the first light source210a, the second light source210b, the third light source210c, and the nthlight source210nmay further include first, second, third, and nthcolor filters310a,310b,310c, and310nfor color separation, unlike the bio imaging system100according to the aforementioned example. That is, the first light source210aincludes the first light emitting element210a-1and the first color filter310a, the second light source210bincludes the second light emitting element210b-1and the second color filter310b, the third light source210cincludes a third light emitting element210c-1and a third color filter310c, and the nthlight source210nincludes the nthlight emitting element210n-1and an nthcolor filter310n. For example, the first light emitting element210a-1may be configured to emit light of a first emission spectrum, the second light emitting element210b-1may be configured to emit light of a second emission spectrum, and the third light emitting element210c-1may be configured to emit light of a third emission spectrum, where the first, second, and third emission spectra are all a same (e.g., common) emission spectrum. As shown, the light source210may include a plurality of light emitting elements210a-1to210n-1that may be configured to emit light of a common emission spectrum (e.g., same emission spectrum), and the bio imaging system100may further include a plurality of color filters310ato310nthat are overlapped with separate, respective (e.g., different) light emitting elements210a-1to210n-1in the z direction extending perpendicular to the in-plane direction of the substrate110, where the plurality of color filters310ato310nare configured to provide wavelength selectivity to the common emission spectrum, for example based on different filters selectively transmitting different wavelength spectra in relation to each other, such that different color filters that are overlapped with different light emitting elements may cause different wavelength spectra of light, of the common emission spectrum of light emitted by the light emitting elements, to be selectively transmitted by the bio imaging system100.

The first, second, third, and nthcolor filters310a,310b,310c, and310nmay be respectively disposed at each position through which light emitted from the first light emitting element210a-1, the second light emitting element210b-1, the third light emitting element210c-1, and the nthlight emitting element210n-1pass and may be for example overlapped (e.g., in the z direction which extends perpendicular to the in-plane direction of the substrate110as shown) with the first light emitting element210a-1, the second light emitting element210b-1, the third light emitting element210c-1, and the nthlight emitting element210n-1, respectively. The first light emitting element210a-1and the first color filter310a, the second light emitting element210b-1and the second color filter310b, the third light emitting element210c-1and the third color filter310c, the nthlight emitting element210n-1, and the nthcolor filter310nmay be independently disposed in contact with each other or may be disposed, for example, through an insulating layer (not shown). For example, each of the first, second and third light sources210a,210b, and210cmay comprise a separate light emitting element of a plurality of light emitting elements (210a-1,210b-1, and210c-1, respectively) that is configured to emit light of a same emission spectrum, and each of the first, second and third light sources210a,210b, and210cmay further comprise a separate color filter of a plurality of color filters (310a,310b, and310c, respectively), wherein the plurality of color filters are overlapped with separate, respective light emitting elements (e.g.,210a-1,210b-1, and210c-1, respectively) of the plurality of light emitting elements (e.g., overlapped in the z direction which extends perpendicular to the in-plane direction of the substrate110).

The first light emitting element210a-1, the second light emitting element210b-1, the third light emitting element210c-1, and the nthlight emitting element210n-1may be configured to emit light of a common emission spectrum (e.g., a same emission spectrum). The common emission spectrum may include transmission spectra of the first, second, third, and nthcolor filters310a,310b,310c, and310n.

The first, second, third, and nthcolor filters310a,310b,310c, and310nmay be configured to selectively transmit light of different wavelength spectra belonging to a common emission spectrum emitted from a first light emitting element210a-1, a second light emitting element210b-1, and a third light emitting element210c-1, and the nthlight emitting element210n-1. That is, the first, second, third, and nthcolor filters310a,310b,310c, and310nmay provide wavelength selectivity to a common emission spectrum. In some example embodiments, the first, second, third, and nthcolor filters310a,310b,310c, and310nmay collectively comprise a color filter310that is overlapped (e.g., in the Z direction extending perpendicular to the upper surface of the substrate110) with a light source210that includes a plurality of light emitting elements (e.g.,210a-1,210b-1,210c-1, and210n-1) that are configured to emit light of a common emission spectrum (e.g., a same emission spectrum).

For example, the first color filter310amay be configured to selectively transmit light of a first transmission spectrum SPT1having a first maximum transmission wavelength λT1,maxamong the common emission spectrum, and may be configured to absorb or reflect other light. For example, the second color filter310bmay be configured to selectively transmit light of a second transmission spectrum SPT2having a second maximum transmission wavelength λT2,maxamong the common emission spectrum, and may be configured to absorb or reflect other light. For example, the third color filter310cmay be configured to selectively transmit light of a third transmission spectrum SPT3having a third maximum transmission wavelength λT3,maxamong the common emission spectrum, and may be configured to absorb or reflect other light. For example, the nthcolor filter310nmay be configured to selectively transmit light of a nthtransmission spectrum SPTnhaving an nthmaximum transmission wavelength λTn,maxamong the common emission spectrum, and may be configured to absorb or reflect other light.

Referring toFIGS.8A to8D, the first, second, third, and nthlight emitting elements210a-1,210b-1,210c-1, and210n-1may be configured to emit light of a common emission spectrum SPE0. Light of the common emission spectrum SPE0passes through the first, second, third, and nthcolor filters310a,310b,310c, and310n, respectively, and each light of the first transmission spectrum SPT1having the first maximum transmission wavelength λT1,max, the second transmission spectrum SPT2having the second maximum transmission wavelength λT2,max, the third transmission spectrum SPT3having the third maximum transmission wavelength λT3,max, and the nthtransmission spectrum SPTnhaving the nthmaximum transmission wavelength λTn,maxmay be selectively transmitted.

The second maximum transmission wavelength λT2,maxmay be a longer wavelength than the first maximum transmission wavelength λT1,max, the third maximum transmission wavelength λT3,maxmay be a longer wavelength than the second maximum transmission wavelength λT2,max, and the nthmaximum transmission wavelength λTn,maxmay be a longer wavelength than the third maximum transmission wavelength λT3,max. The first maximum transmission wavelength λT1,max, the second maximum transmission wavelength λT2,max, the third maximum transmission wavelength λT3,max, and the nthmaximum transmission wavelength λTn,maxmay each be within the common emission spectrum SPE0. The first maximum transmission wavelength λT1,max, the second maximum transmission wavelength λT2,max, the third maximum transmission wavelength λT3,max, and the nthmaximum transmission wavelength λTn,maxmay be separated by a particular (or, alternatively, predetermined) interval. For example, each difference between two adjacent wavelengths of the first maximum transmission wavelength λT1,max, the second maximum transmission wavelength λT2,max, the third maximum transmission wavelength λT3,max, and the nthmaximum transmission wavelength λTn,max (e.g., each of a difference between the first and second maximum transmission wavelengths λT1,maxand λT2,maxand a difference between the second and third maximum transmission wavelengths λT2,maxand λT3,max) may be for example greater than or equal to about 10 nm, within the above range, greater than or equal to about 15 nm, greater than or equal to about 20 nm, greater than or equal to about 30 nm, greater than or equal to about 40 nm, or greater than or equal to about 50 nm, within the above range, about 10 nm to about 500 nm, about 15 nm to about 500 nm, about 20 nm to about 500 nm, about 30 nm to about 500 nm, about 40 nm to about 500 nm, about 50 nm to about 500 nm, about 10 nm to about 300 nm, about 15 nm to about 300 nm, about 20 nm to about 300 nm, about 30 nm to about 300 nm, about 40 nm to about 300 nm, or about 50 nm to about 300 nm.

The full width at half maximum (FWHM) of the transmission spectra SPT1, SPT2, SPT3, and SPTnmay be, for example, less than or equal to about 300 nm, and within the above range, about 10 nm to about 300 nm, about 30 nm to about 250 nm, or about 50 nm to about 200 nm.

Due to such wavelength selectivity of the first, second, third, and nthcolor filters310a,310b,310c, and310n, the first light source210amay be configured to emit light of the first emission spectrum SPE1having a first maximum emission wavelength λE1,maxby the combination of the first light emitting element210a-1and the first color filter310a, the second light source210bmay be configured to emit light of the second emission spectrum SPE2having a second maximum emission wavelength λE2,max by a combination of the second light emitting element210b-1and the second color filter310b, the third light source210cmay be configured to emit light of the third emission spectrum SPE3having a third maximum emission wavelength λE3,maxby a combination of the third light emitting element210c-1and the third color filter310c, and the nthlight source210nmay be configured to emit the light of the nthemission spectrum SPEnhaving the nthmaximum emission wavelength λEn,maxby a combination of the nthlight emitting element210n-1and the nthcolor filter310n.

The second maximum emission wavelength λE2,maxmay be a longer wavelength than the first maximum emission wavelength λE1,max, the third maximum emission wavelength λE3,maxmay be a longer wavelength than the second maximum emission wavelength λE2,max, and the nthmaximum emission wavelength λEn,max) may be a longer wavelength than the third maximum emission wavelength λE3,max. The first maximum emission wavelength λE1,max, the second maximum emission wavelength λE3,max, λE2,max, the third maximum emission wavelength and the nthmaximum emission wavelength λEn,maxmay be separated by a particular (or, alternatively, predetermined) interval. For example, each difference between two adjacent wavelengths of the first maximum emission wavelength λE1,max, the second maximum emission wavelength λE2,max, the third maximum emission wavelength λE3,max, and the nthmaximum emission wavelength λEn,maxmay be for example greater than or equal to about 10 nm, greater than or equal to about 15 nm, greater than or equal to about 20 nm, greater than or equal to about 30 nm, greater than or equal to about 40 nm, or greater than or equal to about 50 nm, within the above range, about 10 nm to about 500 nm, about 15 nm to about 500 nm, about 20 nm to about 500 nm, about 30 nm to about 500 nm, about 40 nm to about 500 nm, about 50 nm to about 500 nm, about 10 nm to about 300 nm, about 15 nm to about 300 nm, about 20 nm to about 300 nm, about 30 nm to about 300 nm, about 40 nm to about 300 nm, or about 50 nm to about 300 nm.

The full width at half maximum (FWHM) of the emission spectra SPE1, SPE2, SPE3, and SPEnmay be, for example, less than or equal to about 300 nm, and within the above range, about 10 nm to about 300 nm, about 30 nm to about 250 nm, or about 50 nm to about 200 nm.

Since the sensor220may be configured to detect light emitted from the first, second, third, and nthlight sources210a,210b,210c, and210nand reflected by internal tissue of a living body, like the aforementioned example, the absorption spectrum SPA of the sensor220may include light of all wavelength spectra emitted from the first, second, third, and nthlight sources210a,210b,210c, and210n.

Hereinafter, another example of the bio imaging system100shown inFIGS.1to2Bwill be described with reference toFIG.9along withFIGS.3to6and8.

FIG.9is a cross-sectional view showing another example of the bio imaging system ofFIG.3according to some example embodiments.

Referring toFIG.9, a bio imaging system100according to some example embodiments includes a substrate110; a plurality of light sources210arranged on the substrate110; and a plurality of sensors220arranged on the substrate110, like the aforementioned example.

However, unlike the aforementioned example, the bio imaging system100according to the present example may include the first, second, third, and nthcolor filters310a,310b,310c, and310nconfigured to transmit light of different wavelength spectra in relation to each other, under the light source210configured to emit light of a common wavelength spectrum. That is, instead of the first, second, third and nthlight sources210a,210b,210c, and210n, which are separated from each other and overlapped with the first, second, third, and nth color filters310a,310b,310c, and310n, respectively, one light source210overlapped with the first, second, third, and nth color filters310a,310b,310c, and310nmay be included. A plurality of light sources210may be arranged along rows and/or columns of the substrate110.

The light source210may be configured to emit light of a common emission spectrum (e.g., white light), and the first, second, third, and nthcolor filters310a,310b,310c, and310nmay provide wavelength selectivity to the common emission spectrum, like the aforementioned example. Therefore, as shown inFIG.8, the light source210, the first, second, third, and nthcolor filters310a,310b,310c, and310n, and the sensor220have the optical characteristics shown inFIGS.8A to8D.

Hereinafter, an example of the bio imaging system100shown inFIGS.1to2Bwill be described with reference toFIGS.10to13B.

FIG.10is a plan view showing an example of the bio imaging system shown inFIGS.1to2C,FIG.11is a cross-sectional view of an example of the bio imaging system ofFIG.10taken along line XI-XI′,FIGS.12A,12B,12C, and12Dare cross-sectional view showing an example of the sensor shown inFIGS.10and11, andFIGS.13A and13Bare graphs showing an example of wavelength spectra of a light source and a sensor of the bio imaging system shown inFIGS.10and11.

Referring toFIGS.10and11, a bio imaging system100according to some example embodiments includes a substrate110; a plurality of light sources210arranged on the substrate110; and a plurality of sensors220arranged on the substrate110and configured to absorb light of different wavelength spectra. As described above, the plurality of light sources210and the plurality of sensors220may be on the rigid region110aof the substrate110.

The light source210may include a light emitting element210-1including a pair of electrodes211and212facing each other and a light emitting layer213between the pair of electrodes211and212, as shown inFIG.2A. The light emitting characteristics of the light source210may be the same or substantially the same as the light emitting characteristics of the light emitting layer213, and the emission spectrum of the light source210may include light of all absorption spectra absorbed by the sensor220.

The sensor220includes a first sensor220a, a second sensor220b, and a third sensor220cthat are separated from each other. The sensor220may additionally include an nthsensor220nin addition to the first sensor220a, the second sensor220b, and the third sensor220c, wherein n may be an integer of 4 to 10. The nthsensor220ndoes not mean one sensor, but an nthsensor. For example, when n is 7, the sensor220may further include fourth, fifth, sixth, and seventh sensors in addition to the first sensor220a, the second sensor220b, and the third sensor220c. The nthsensor220nmay be omitted.

The first sensor220a, the second sensor220b, the third sensor220c, and the nthsensor220nmay be arranged in parallel (e.g., may extend in a linear sequence) along an in-plane direction (e.g., x direction, y direction, or xy direction) of the substrate110and light of different wavelength spectra belonging to the visible to infrared wavelength spectra may be absorbed. For example, the first sensor220a, the second sensor220b, the third sensor220c, and the nthsensor220nmay be configured to selectively absorb light of different wavelength spectra (e.g., different absorption spectra) in relation to each other within a wavelength range of about 380 nm to about 3 μm, respectively, and a plurality of images obtained by light of different absorption spectra in relation to each other are combined to obtain a three-dimensional image of an internal tissue of a living body.

The first sensor220a, second sensor220b, third sensor220c, and nthsensor220nmay include each a first light absorption element220a-1, a second light absorption element220b-1, a third light absorption element220c-1, and an nthlight absorption element220n-1which are configured to absorb light of different absorption spectra in relation to each other. That is, the first sensor220amay include the first light absorption element220a-1, the second sensor220bmay include the second light absorption element220b-1, the third sensor220cmay include the third light absorption element220c-1, and the nthsensor220nmay include the nthlight absorption element220n-1. Each of the first, second, third, and nthlight absorption elements220a-1,220b-1,220c-1, and220n-1may be an inorganic photoelectric conversion element or an organic photoelectric conversion element.

Referring to ofFIGS.12A to12D, the first light absorption element220a-1may include a pair of electrodes221aand222afacing each other and a light absorption layer223abetween the pair of electrodes221aand222a, and the second light absorption element220b-1may include a pair of electrodes221band222bfacing each other and a light absorption layer223bbetween the pair of electrodes221band222b, the third light absorption element220c-1may include a pair of electrodes221cand222cfacing each other and a light absorption layer223cbetween the pair of electrodes221cand222c, and the nthlight absorption element220n-1may include a pair of electrodes221nand222nfacing each other and a light absorption layer223nbetween the pair of electrodes221nand222n. The descriptions of the pair of electrodes221and222and the light absorption layer223is as described above.

The absorption spectrum of the light absorbed by the first light absorption element220a-1, second light absorption element220b-1, third light absorption element220c-1, and nthlight absorption element220n-1may be determined by the light absorption layers223a,223b,223c, and223n, and the light absorption layers223a,223b,223c, and223nmay be configured to absorb light of different emission spectra in relation to each other. For example, each of the first light absorption element220a-1, second light absorption element220b-1, third light absorption element220c-1, and nthlight absorption element220n-1may be configured to absorb light of a first absorption spectrum SPA1having a first maximum absorption wavelength λA1,max, a second absorption spectrum SPA2having a second maximum absorption wavelength λA2,max, a third absorption spectrum SPA3having a third maximum absorption wavelength λA3,max, and an nthabsorption spectrum SPAnhaving an nthmaximum absorption wavelength λAn,max, wherein the first maximum absorption wavelength λA1,max, the second maximum absorption wavelength λA2,max, the third maximum absorption wavelength λA3,max, and the nthmaximum absorption wavelength λAn,maxmay be different from each other.

Referring toFIG.13, the first light absorption element220a-1may be configured to absorb light of the first absorption spectrum SPA1having the first maximum absorption wavelength λA1,max, the second light absorption element220b-1may be configured to absorb light of the absorption spectrum SPA2having the second maximum absorption wavelength λA2,max, the third light absorption element220c-1may be configured to absorb light of the absorption spectrum SPA3having the third maximum absorption wavelength λA3,max, and the nthlight absorption element220n-1may be configured to absorb light of the absorption spectrum SPAnhaving the nthmaximum absorption wavelength λAn,max. That is, the light absorption layer223amay be configured to absorb light of the absorption spectrum having the first maximum absorption wavelength λA1,max, the light absorption layer223bmay be configured to absorb light of the absorption spectrum having the second maximum absorption wavelength λA2,max, the light absorption layer223cmay be configured to absorb light of the absorption spectrum having the third maximum absorption wavelength λA3,max, and the light absorption layer223nmay be configured to absorb light of the absorption spectrum having the nthmaximum absorption wavelength λAn,max.

The second maximum absorption wavelength λA2,maxmay be a longer wavelength than the first maximum absorption wavelength λA1,max, the third maximum absorption wavelength λA3,maxmay be a longer wavelength than the second maximum absorption wavelength λA2,max, and the nthmaximum absorption wavelength λAn,maxmay be a longer wavelength than the third maximum absorption wavelength λA3,max. The first maximum absorption wavelength λA1,max, the second maximum absorption wavelength λA2,max, the third maximum absorption wavelength λA3,max, and the nthmaximum absorption wavelength λAn,maxmay be separated by a particular (or, alternatively, predetermined) interval. For example, each difference between two adjacent wavelengths of the first maximum absorption wavelength λA1,max, the second maximum absorption wavelength λA2,max, the third maximum absorption wavelength λA3,max, and the nthmaximum absorption wavelength λAn,max, for example a difference between the first and second maximum absorption wavelengths λA1,maxand λA2,maxand a difference between the second and third maximum absorption wavelengths λA2,maxand λA3,max, may be for example greater than or equal to about 10 nm, within the range, greater than or equal to about 15 nm, greater than or equal to about 20 nm, greater than or equal to about 30 nm, greater than or equal to about 40 nm, or greater than or equal to about 50 nm, within the range, about 10 nm to about 500 nm, about 15 nm to about 500 nm, about 20 nm to about 500 nm, about 30 nm to about 500 nm, about 40 nm to about 500 nm, about 50 nm to about 500 nm, about 10 nm to about 300 nm, about 15 nm to about 300 nm, about 20 nm to about 300 nm, about 30 nm to about 300 nm, about 40 nm to about 300 nm or about 50 nm to about 300 nm.

The first maximum absorption wavelength λA1,max, the second maximum absorption wavelength λA2,max, the third maximum absorption wavelength λA3,maxand the nthmaximum absorption wavelength λAn,maxmay belong to a visible to infrared wavelength spectra, and may be for example independently within about 380 nm to about 3 μm, about 400 nm to about 2 μm, about 450 nm to about 1500 nm, about 470 nm to about 1150 nm, about 480 nm to about 1100 nm, about 500 nm to about 1000 nm, about 550 nm to about 1000 nm, or about 600 nm to about 1000 nm. For example, the first maximum absorption wavelength λA1,max, the second maximum absorption wavelength λA2,max, the third maximum absorption wavelength λA3,max, and the nthmaximum absorption wavelength λAn,maxmay each independently belong to one of a blue wavelength spectrum, a green wavelength spectrum, a red wavelength spectrum, or a (near) infrared wavelength spectrum, wherein the blue wavelength spectrum may be greater than or equal to about 400 nm and less than about 500 nm, the green wavelength spectrum may be greater than or equal to about 500 nm and less than or equal to about 600 nm, the red wavelength spectrum may be greater than about 600 nm and less than or equal to about 700 nm, and the (near) infrared wavelength spectrum may be greater than about 700 nm and less than or equal to about 3000 nm.

The full width at half maximum (FWHM) of the absorption spectra SPA1, SPA2, SPA3, and SPAnmay be, for example, less than or equal to about 300 nm, and within the above range, about 10 nm to about 300 nm, about 30 nm to about 250 nm, or about 50 nm to about 200 nm.

Since the light source210supplies light absorbed by the first, second, third, and nthsensors220a,220b,220c, and220n, the emission spectrum SPEof the light source210may include light of all wavelength spectra absorbed by the first, second, third, and nthsensors220a,220b,220c, and220n.

For example, the emission spectrum of light supplied from the light source210may include all absorption spectra of the first to nthsensors220a,220b,220c, and220nand may be for example, within about 380 nm to about 3 μm, about 400 nm to about 2 μm, about 450 nm to about 1500 nm, about 470 nm to about 1150 nm, about 480 nm to about 1100 nm, about 500 nm to about 1000 nm, about 550 nm to about 1000 nm, or about 600 nm to about 1000 nm. For example, when the first, second, third sensor220a,220b, and220care configured to absorb light of a blue wavelength spectrum, a green wavelength spectrum, and a red wavelength spectrum, respectively, the light source210may be configured to emit light in in a white wavelength spectrum including the blue wavelength spectrum, green wavelength spectrum, and red wavelength spectrum.

In the bio imaging system100according to the present example, a plurality of sensors220a,220b,220c, and220nconfigured to absorb light of different absorption spectra in relation to each other may provide a plurality of images of internal tissue of a living body according to the depth direction from the skin surface by using the difference in the penetration depth of light according to the wavelength. These the plurality of images are combined to obtain information such as a location, shape, size, and/or thickness of the internal tissues of the living body (e.g., blood vessels), and this information may be used to obtain spatial information of the internal tissues of the living body. In addition, this spatial information may be separated and/or extracted to effectively obtain information of the internal tissues of the living body present at a specific depth from the skin surface.

Specifically, as described above, the light irradiated from the light source210has a different penetration depth of light from the skin surface according to the wavelength, and light of a relatively long wavelength spectrum may penetrate relatively deeper than light of a relatively short wavelength spectrum. Therefore, in the bio imaging system100shown inFIGS.10to13B, the image obtained by the third sensor220cconfigured to absorb light of the third absorption spectrum SPA3having the third maximum absorption wavelength λA3,maxmay be an image at a position deeper than the image obtained from the second sensor220bconfigured to absorb light of the second absorption spectrum SPA2having a second maximum absorption wavelength λA2,max, which is a relatively short wavelength, and the image obtained from the second sensor220bconfigured to absorb light of the second absorption spectrum SPA2having the second maximum absorption wavelength λA2,maxmay be an image of a position deeper than the image obtained by the first sensor220aconfigured to absorb light of the first absorption spectrum SPA1of the first maximum absorption wavelength λA1,max, which is a relatively short wavelength.

Therefore, by extracting the difference between the image obtained from the third sensor220cand the image obtained from the second sensor220b, image information at a depth at which only light of a wavelength corresponding to the third absorption spectrum SPA3penetrates may be obtained, and similarly, by extracting the difference between the image obtained from the second sensor220band the image obtained from the first sensor220a, image information at a depth at which only light of a wavelength corresponding to the second absorption spectrum SPA2penetrates may be obtained. Accordingly, it is possible to effectively obtain image information of an internal tissue of a living body located at a specific depth from the skin surface.

In this way, differences between images obtained from any two sensors among n sensors220a,220b,220c, and220nconfigured to absorb light of different absorption spectra in relation to each other are extracted and combined, and thereby, spatial information may be secured in the depth direction.

FIG.30is a schematic cross-sectional view showing an example of a method of obtaining image information of an internal tissue of a living body using the bio imaging system ofFIG.10.

Like the aforementioned example, a bio imaging method using the bio imaging system100may include fixing the bio imaging system100on the skin S; radiating light into the skin S by turning on the light source210; absorbing light passing the skin S and scattered and reflected by the internal tissues of the living body such as blood vessel BV by the sensor220to obtain a plurality of images by the light of a wavelength spectrum different from each other; extracting the plurality of images of the internal tissues of the living body such as the blood vessel BV depending on a depth from the surface of the skin S; and combining the plurality of images (e.g., plurality of extracted images) of the internal tissues of the living body such as the blood vessel BV to obtain a three-dimensional image of the internal tissues of the living body.

Referring toFIG.30together withFIGS.25and27A and27B, the sensor220may include first, second, and third sensors (e.g.,220a,220b, and220c) configured to absorb light of different absorption spectra in relation to each other. The depths D1, D2, and D3at which the light irradiated from the light irradiated from the light source210penetrate according to the wavelength have a particular (or, alternatively, predetermined) distribution, and images of an internal tissue of a living body reflected at different depths according to wavelengths may be obtained from the first, second, and third sensors220a,220b, and220cconfigured to absorb light of different absorption spectra in relation to each other. For example, since among the first, second, and third sensors220a,220b,220c, the first sensor220ais configured to absorb light of the first absorption spectrum SPA1of the relatively shortest wavelength, and the third sensor220cis configured to absorb light of the absorption spectrum SPA3of the relatively longest wavelength, the signals obtained by irradiation of light of the first to third absorption spectra SPA1, SPA2, and SPA3may provide images M1, M2, and M3from a relatively close depth D1to the deepest depth D3from the skin surface S1. Based on these images M1, M2, and M3, the image difference according to each depth D1, D2, and D3is extracted, and the lowest point, the middle point, and the highest point of the blood vessel BV are specified to obtain a three-dimensional image of the blood vessel BV. For example, extracting differences between the images M1, M2, and M3may include extracting an image of the internal tissue of the living body located at a first depth D1from the skin S surface based on a difference between an image obtained based on the second sensor220babsorbing light and an image obtained based on the first sensor220aabsorbing light, and extracting an image of the internal tissue of the living body located at a second depth D2deeper than the first depth D1based on a difference between an image obtained based on the third sensor220cabsorbing light and the image obtained based on the second sensor220babsorbing light. Spatial information such as the location, shape, size and/or thickness of the blood vessel BV may be confirmed from the three-dimensional image of the blood vessel BV.

When two or more of the plurality of blood vessels BV1and BV2are located in the depth direction, an image of the blood vessel BV located at a specific depth may be obtained by separating the images of the plurality of blood vessels BV and extracting the difference.

That is, the depths D1, D2, and D3at which the light irradiated from the light source210penetrate according to the wavelength have a particular (or, alternatively, predetermined) distribution, and information of blood vessels BV1and BV2reflected by the different depths D1, D2, and D3according to the wavelength may be selectively obtained from a plurality of sensors220a,220b,220cconfigured to absorb light of different wavelength spectra. Image information obtained from light of the first to third absorption spectra may each include spatial information from a depth D1relatively close to a deepest depth D3from the skin surface S1respectively, and it is possible not only to obtain a three-dimensional image of each blood vessel BV1and BV2, by extracting the difference between the plurality of images and specifying the lowest point, the middle point, and the highest point of each blood vessel BV1and BV2, but also to obtain a clear image of the blood vessel BV2without reducing the resolution caused by the blood vessel BV1, by extracting the difference between the image obtained from the blood vessel BV1and the image obtained from the blood vessel BV1. Therefore, when the plurality of blood vessels BV1and BV2are located in the depth direction from the skin surface S1, spatial information of the internal tissues of the living body may be effectively checked in this manner. Here, an example in which two blood vessels BV1and BV2are located in the depth direction has been described, but a case in which n blood vessels are located in the depth direction may also be described.

Meanwhile, the bio imaging method may further include obtaining a correction image before obtaining the aforementioned three-dimensional image. The correction image is for excluding an influence of the light characteristics (e.g., scattering and/or absorption) of the skin caused by differences in skin color and thickness of subcutaneous tissue for each individual, and may be obtained based on, for example, a point spread function. For example, the correction image may be obtained by operating only some of the sensor220of the first position (specific position) of the bio imaging system100to obtain an image according to the wavelength spectrum of the first position corresponding to the operated some of the sensor220and by operating only some of the sensor220of the second position (specific position) of the bio imaging system100to obtain an image according to the wavelength spectrum of the second position corresponding to the operated some of the sensor220, and in this way, operating only some of the sensor220of the nthposition to obtain an image according to the wavelength spectrum of the nthposition corresponding to the operated some of the sensor. The correction image may be applied to the plurality of extracted images to correct the plurality of extracted images. The corrected extracted images may then be combined to obtain the three-dimensional image. By correcting the aforementioned plurality of extracted images using the correction image, the effect of the optical characteristics of the skin may be excluded to obtain a clear three-dimensional image.

Hereinafter, another example of the bio imaging system100shown inFIGS.1and2A to2Cwill be described with reference toFIG.14along withFIGS.10to13.

FIG.14is a cross-sectional view of another example of the bio imaging system ofFIG.10taken along line XI-XI′ andFIGS.15A,15B, and15Care graphs showing an example of wavelength spectra of a light source and a sensor of the bio imaging system shown inFIGS.10and14.

Referring toFIG.14, a bio imaging system100according to an example includes a substrate110; a plurality of light sources210arranged on the substrate110; and a plurality of sensors220arranged on the substrate110, wherein the sensors220include a first sensor220a, a second sensor220b, a third sensor220c, and optionally nthsensor220nwhich are separated from each other and configured to absorb light of different wavelength spectra, like the aforementioned example.

However, in the bio imaging system100according to the present example, unlike the bio imaging system100according to the aforementioned example, the first, second, third, and nthsensors220a,220b,220c, and220nmay include a first light absorption element220a-1, a second light absorption element220b-1, a third light absorption element220c-1, and an nthlight absorption element220n-1which each is configured to absorb light of a common absorption spectrum (e.g., same absorption spectrum), wherein each of the first sensor220a, the second sensor220b, the third sensor220c, and the nthsensor220nmay further include first, second, third, and nthcolor filters320a,320b,320c, and320nfor color separation. That is, the first sensor220aincludes a first light absorption element220a-1and a first color filter320a, the second sensor220bincludes a second light absorption element220b-1and a second color filter320b, the third sensor220cincludes a third light absorption element220c-1and a third color filter320c, and the nthsensor220nincludes the nthlight absorption element220n-1and an nthcolor filter320n. As shown, each sensor of the first, second, and third sensors220ato220cmay comprise a separate light absorption element of a plurality of light absorption elements (e.g., a respective one of light absorption elements220a-1to220c-1) and a separate color filter of a plurality of color filters (e.g., a respective one of color filters320ato320c), where the separate color filter of a given sensor is overlapped with the separate light absorption element of the given sensor in the Z direction extending perpendicular to the upper surface of the substrate110, wherein the plurality of light absorption elements220a-1to220c-1of the first, second, and third sensors220ato220care configured to selectively absorb light of a same absorption spectrum.

The first, second, third, and nthcolor filters320a,320b,320c, and320n(which may be referred to herein as the a plurality of color filters) may be respectively at each position through which light emitted from the first light absorption element220a-1, the second light absorption element220b-1, the third light absorption element220c-1, and the nthlight absorption element220n-1pass, may be for example overlapped with the first light absorption element220a-1, the second light absorption element220b-1, the third light absorption element220c-1, and the nthlight absorption element220n-1, respectively. The first light absorption element220a-1and the first color filter320a, the second light absorption element220b-1and the second color filter320b, the third light absorption element220c-1and the third color filter320c, and the nthlight absorption element220n-1and the nthcolor filter320nmay be independently in contact with each other or may be, for example, through an insulating layer (not shown).

The first light absorption element220a-1, the second light absorption element220b-1, the third light absorption element220c-1, and the nthlight absorption element220n-1may be configured to absorb (e.g., selectively absorb) light of a common absorption spectrum. The common absorption spectrum may include transmission spectra of the first, second, third and nthcolor filters320a,320b,320c, and320n.

The first, second, third, and nthcolor filters320a,320b,320c, and320nmay be configured to selectively transmit light of different wavelength spectra belonging to a common absorption spectrum absorbed in the first light absorption element220a-1, the second light absorption element220b-1, the third light absorption element220c-1, and the nthlight absorption element220n-1. That is, the first, second, third, and nthcolor filters320a,320b,320c, and320nmay provide wavelength selectivity to a common absorption spectrum.

For example, the first color filter320amay be configured to selectively transmit light of a first transmission spectrum having a first maximum transmission wavelength λT1,maxamong the common absorption spectrum, and may be configured to absorb or reflect other light. For example, the second color filter320bmay be configured to selectively transmit light of a second transmission spectrum having a second maximum transmission wavelength λT2,maxamong the common absorption spectrum, and may be configured to absorb or reflect other light. For example, the third color filter320cmay be configured to selectively transmit light of a third transmission spectrum having a third maximum transmission wavelength λT3,maxamong the common absorption spectrum, and may be configured to absorb or reflect other light. For example, the nthcolor filter320nmay be configured to selectively transmit light of a nthtransmission spectrum having an nthmaximum transmission wavelength λTn,maxamong the common absorption spectrum, and may be configured to absorb or reflect other light.

Referring toFIGS.15A,15B, and15C, the light source210may be configured to emit light of a particular (or, alternatively, predetermined) emission spectrum SPE0. Light of the particular (or, alternatively, predetermined) emission spectrum SPE0is reflected by an internal tissue of a living body (e.g., blood vessel) and passes the first, second, third and nthcolor filters320a,320b,320c, and320n, respectively, and light passing the first, second, third and nthcolor filters320a,320b,320c, and320n, respectively may be light of a transmission spectrum SPT1having a first maximum transmission wavelength λT1,max, a transmission spectrum SPT2having a second maximum transmission wavelength λT2,max, a transmission spectrum SPT3having a third maximum transmission wavelength λT3,max, and a transmission spectrum SPTnhaving an nthmaximum transmission wavelength λTn,max. That is, light passing through the first, second, third, and nthcolor filters320a,320b,320c, and320n, respectively, may have wavelength selectivity. Each of the first to nthmaximum transmission wavelengths λT1,maxto λTn,maxmay be within the same absorption spectrum SPA that the plurality of light absorption elements220a-1to220n-1are configured to absorb.

Due to such wavelength selectivity of the first, second, third, and nthcolor filters320a,320b,320c, and320n, the first sensor220amay be configured to absorb light of the absorption spectrum SPA1having a first maximum absorption wavelength λA1,max by the combination of the first light absorption element220a-1and the first color filter320a, the second sensor220bmay be configured to absorb light of the absorption spectrum SPA2having a second maximum absorption wavelength λA2,maxby the combination of the second light absorption element220b-1and the second color filter320b, the third sensor220c220amay be configured to absorb light of the absorption spectrum SPA3having a third maximum absorption wavelength λA3,maxby the combination of the third light absorption element220c-1and the third color filter320c, and the nthsensor220nmay be configured to absorb light of the absorption spectrum SPAnhaving the nthmaximum absorption wavelength λAn,maxby the combination of the light absorption element220n-1and the nthcolor filter320n.

The second maximum absorption wavelength λA2,maxmay be a longer wavelength than the first maximum absorption wavelength λA1,max, the third maximum absorption wavelength λA3,maxmay be a longer wavelength than the second maximum absorption wavelength λA2,max, and the nthmaximum absorption wavelength λAn,maxmay be a longer wavelength than the third maximum absorption wavelength λA3,max. The first maximum absorption wavelength λA1,max, the second maximum absorption wavelength λA2,max, the third maximum absorption wavelength λA3,max, and the nthmaximum absorption wavelength λAn,maxmay be separated by a particular (or, alternatively, predetermined) interval. For example, each difference between two adjacent wavelengths of the first maximum absorption wavelength λA1,max, the second maximum absorption wavelength λA2,max, the third maximum absorption wavelength λA3,max, and the nthmaximum absorption wavelength λAn,max(e.g., a difference between the first and second maximum transmission wavelengths λA1,maxand λA2,maxand a difference between the second and third maximum transmission wavelengths λA2,maxand λA3,max) may be for example greater than or equal to about 10 nm, greater than or equal to about 15 nm, greater than or equal to about 20 nm, greater than or equal to about 30 nm, greater than or equal to about 40 nm, or greater than or equal to about 50 nm, within the above range, about 10 nm to about 500 nm, about 15 nm to about 500 nm, about 20 nm to about 500 nm, about 30 nm to about 500 nm, about 40 nm to about 500 nm, about 50 nm to about 500 nm, about 10 nm to about 300 nm, about 15 nm to about 300 nm, about 20 nm to about 300 nm, about 30 nm to about 300 nm, about 40 nm to about 300 nm, or about 50 nm to about 300 nm.

Each of the full width at half maximum (FWHM) of the transmission spectra SPT1, SPT2, SPT3, and SPTnand the absorption spectra SPA1, SPA2, SPA3, and SPAnmay be, for example, less than or equal to about 300 nm, and within the above range, about 10 nm to about 300 nm, about 30 nm to about 250 nm, or about 50 nm to about 200 nm.

Hereinafter, an example of the bio imaging system100shown inFIGS.1and2will be described with reference toFIGS.16and17.

FIG.16is a plan view showing an example of the bio imaging system shown inFIGS.1to2BandFIG.17is a cross-sectional view of an example of the bio imaging system ofFIG.16taken along line XVII-XVII′.

Referring toFIGS.16and17, a bio imaging system100according to some example embodiments includes a substrate110; a plurality of light sources210including first, second, third, and nthlight sources210a,210b,210c, and210narranged on the substrate110and configured to emit light of different wavelength spectrum; and a plurality of sensors220including first, second, third, and nthsensors220a,220b,220c, and220narranged on the substrate110and configured to absorb light of different wavelength spectrum. Descriptions for the first, second, third, and nthlight sources210a,210b,210c, and210nand the first, second, third, and nthsensors220a,220b,220c, and220nare the same as described above. The bio imaging system100according to the present example may have a configuration in which the aforementioned examples are combined according to a location. For example, as shown inFIGS.16and17, a bio imaging system100may include a light source210that comprises first, second, and third light sources210a,210b, and210cthat may be configured to emit (e.g., selectively emit) light of different emission spectra within visible to infrared wavelength spectra, and the bio imaging system100may include a sensor220that comprises first, second, and third sensors220a,220b, and220cthat may be configured to absorb (e.g., selectively absorb) light of different absorption spectra in relation to each other within the visible to infrared wavelength spectra. As shown, the light source210and the sensor220may extending parallel (e.g., extend in a linear sequence) along an in-plane direction of the substrate110.

Hereinafter, an example of the bio imaging system100shown inFIGS.1to2Bwill be described with reference toFIGS.18to21.

FIG.18is a plan view showing an example of the bio imaging system shown inFIGS.1to2C,FIG.19is a cross-sectional view of an example of the bio imaging system ofFIG.18taken along line XIX-XIX′,FIG.20is a cross-sectional view of another example of the bio imaging system ofFIG.18taken along line XIX-XIX′, andFIG.21is a cross-sectional view of another example of the bio imaging system ofFIG.18taken along line XIX-XIX′.

Referring toFIGS.18to21, the bio imaging system100according to each example may include a substrate110; a plurality of light sources210arranged on the substrate110; and a plurality of sensors220arranged on the substrate110. The plurality of light sources210and the plurality of sensors220may be alternately arranged along rows and/or columns. Each light source210may include a light emitting element210-1, and each sensor220may include a light absorption element220-1.

However, referring toFIGS.18and19, unlike the light absorption element220-1according to the aforementioned examples, the light absorption element220-1may be a wavelength-tunable light absorption element whose absorption spectrum is configured to change depending on an applied voltage bias and which may be configured to selectively absorb light of an absorption spectrum that changes based on a voltage applied to the wavelength-tunable light absorption element. For example, some of the light absorption elements220-1may be configured to absorb light of a first absorption spectrum having a first maximum absorption wavelength λA1,maxby applying a first voltage bias, some of the light absorption elements220-1may be configured to absorb light of a second absorption spectrum having a second maximum absorption wavelength λA2,maxby applying a second voltage bias different from the first voltage bias, some of the light absorption elements220-1may be configured to absorb light of a third absorption spectrum having a third maximum absorption wavelength λA3,maxby applying a third voltage bias different from the first and second voltage biases, and some of the light absorption elements220-1may be configured to absorb light of the nthabsorption spectrum having the nthabsorption wavelength λAn,maxby applying an nthvoltage bias different from the first, second, and third voltage biases. Accordingly, different voltage biases may be applied to each light absorption element220-1to absorb light of a desired absorption spectrum, and thereby the same or substantially the same effect as the aforementioned first, second, third, and nthlight absorption elements220a-1,220b-1,220c-1, and220n-1may be obtained.

As another example, the light emitting element210-1may be a wavelength-tunable light emitting element instead of the aforementioned wavelength-tunable light absorption element and which may be configured to selectively emit light of an emission spectrum that changes based on a voltage applied to the wavelength-tunable light emitting element. For example, some of the light emitting elements210-1may be configured to emit light of a first emission spectrum having a first maximum emission wavelength λE1,maxby applying a first voltage bias, some of the light emitting elements210-1may be configured to emit light of a second emission spectrum having a second maximum emission wavelength λE2,maxby applying a second voltage bias different from the first voltage bias, some of the light emitting elements210-1may be configured to emit light of a third emission spectrum having a third maximum emission wavelength λE3,maxby applying a third voltage bias different from the first and second voltage biases, and some of the light emitting elements210-1may be configured to emit light of an nthemission spectrum having the nthmaximum emission wavelength λEn,maxby applying an nthvoltage bias different from the first, second, and third voltage biases. Accordingly, different voltage biases may be applied to each light emitting element210-1to emit light of a desired emission spectrum, and thereby the same or substantially the same effect as the aforementioned first, second, third, and nthlight emitting elements210a-1,210b-1,210c-1, and210n-1may be obtained.

Next, referring toFIGS.18and20, the light source210may include a light emitting element210-1and a wavelength-tunable color filter330. The light emitting element210-1may be configured to emit light of a very wide emission spectrum, such as white light. The wavelength-tunable color filter330may have a transmission wavelength spectrum and/or transmittance changeable depending on a voltage applied thereto (e.g., applied to the wavelength-tunable color filter330) and include, for example, an electro-optical material such as a liquid crystal, a plasmon material, and the like but is not limited thereto. For example, some of the wavelength-tunable color filters330may be configured to selectively transmit light of a first transmission spectrum having a first maximum transmission wavelength λT1,maxamong light emitted from the light emitting element210-1by applying a first voltage bias, some of the wavelength-tunable color filters330may be configured to selectively transmit light of a second transmission spectrum having a second maximum transmission wavelength λT2,maxamong the light emitted from the light emitting element210-1by applying a second voltage bias differing from the first voltage bias, and some of the wavelength-tunable color filters330may be configured to selectively transmit light of a third transmission spectrum having a third maximum transmission wavelength λT3,maxamong the light emitted from the light emitting element210-1by applying a third voltage bias differing from the first and second voltage biases. Accordingly, different voltage biases may be applied to each light source210to emit light of a desired emission spectrum, and thereby the same or substantially the same effect as the aforementioned first, second, third, and nthlight emitting elements210a-1,210b-1,210c-1, and210n-1may be obtained.

As described herein, voltage biases may be applied to a wavelength-tunable element, layer, or the like (e.g., wavelength tunable color filter330) by the controller101of the bio imaging system100, for example based on a processor of the controller executing a program of instruction to apply a particular voltage bias to the wavelength tunable element to achieve a particular result (e.g., to cause the wavelength-tunable color filter330to selectively transmit light in a particular transmission spectrum having a particular maximum transmission wavelength).

Referring toFIGS.18and21, a sensor220may include the light absorption element220-1and the wavelength-tunable color filter330. The light source210and the light absorption element220-1may be configured to absorb, for example, light of a very wide wavelength spectrum such as white light and thus provide wavelength selectivity by the wavelength-tunable color filter330. For example, some of the wavelength-tunable color filters330may be configured to selectively transmit light of a first transmission spectrum having a first maximum transmission wavelength λT1,maxamong light reflected by the internal tissues of a living body (e.g., blood vessels) by applying a first voltage bias, some of the wavelength-tunable color filters330may be configured to selectively transmit light of a second transmission spectrum having a second maximum transmission wavelength λT2,maxamong the light reflected by the internal tissues of a living body (e.g., blood vessels) by applying a second voltage bias differing from the first voltage bias, and some of the wavelength-tunable color filters330may be configured to selectively transmit light of a third transmission spectrum having a third maximum transmission wavelength λT3,maxamong the light reflected by the internal tissues of a living body (e.g., blood vessels) by applying a third voltage bias differing from the first and second voltage biases. Accordingly, different voltage biases may be applied to each sensor220to absorb light of a desired absorption spectrum and thereby the same or substantially the same effect as the aforementioned first, second, third and nthlight absorption elements220a-1,220b-1,220c-1, and220n-1may be obtained.

Accordingly, the bio imaging system100may include a color filter330overlapped, in a direction that is perpendicular to an in-plane direction of the substrate110(e.g., the z direction as shown) with the light source210or the sensor220, where the color filter330is a wavelength-tunable color filter configured to selectively transmit light in a transmission spectrum (e.g., a variable transmission spectrum) that may change based on a voltage applied to the color filter330.

Hereinafter, an example of the bio imaging system100will be described with reference toFIGS.22to24.

FIG.22is a plan view showing an example of a bio imaging system according to some example embodiments,FIG.23is a cross-sectional view of a portion of an example of the bio imaging system ofFIG.22, andFIG.24is a cross-sectional view of a portion of another example of the bio imaging system ofFIG.22.

The bio imaging system100according to some example embodiments includes a substrate110; a plurality of light sources210arranged on the substrate110; and a plurality of sensors220arranged on the substrate110, like the aforementioned example embodiments.

However, referring toFIGS.22and23, in the bio imaging system100according to some example embodiments, unlike the aforementioned example embodiments, a plurality of light sources210and a plurality of sensors220are at a different height from the substrate110, where “height” refers to a distance from the substrate110in a direction that extends perpendicular to an in-plane direction of the substrate110(e.g., a direction that extends perpendicular to the in-plane direction of the substrate110). For example, as shown inFIGS.22-23, the bio imaging system100may include a light source array210A, including a plurality of light sources210, and a sensor array220A, including a plurality of sensors220, wherein the light source array210A and the sensor array220A are at different heights from the substrate110in a direction extending perpendicular to an in-plane direction of the substrate110(e.g., the z direction, which extends perpendicular to an upper surface of the substrate110).

In other words, the plurality of light sources210at a first height from the substrate110are arranged, for example, along a row and/or a column to form a light source array210A, and the plurality of sensors220at a second height from the substrate110are arranged, for example, along a row and/or a column to form a sensor array220A. For example, the first height may be higher than the second height. A transparent layer120may be between the light source array210A and the sensor array220A, and the transparent layer120may be a stretchable transparent layer.

Referring toFIG.24, the bio imaging system100according to some example embodiments includes a substrate110; a light source array210A and a sensor array220A at a different heights in relation to each other on the substrate110; and a transparent layer120between the light source array210A and the sensor array220A, like the aforementioned example.

However, the bio imaging system100according to some example embodiments, unlike the aforementioned example embodiments, further includes a light diffusion layer270under the light source array210A. The light diffusion layer270may be between the substrate110and the light source array210A, for example, on the whole surface of the substrate110. As shown, the light diffusion layer270may be between the light source array210A and the sensor array220A in the direction extending perpendicular to the in-plane direction of the substrate110(e.g., the Z direction). The light diffusion layer270may be configured to scatter and diffuse light irradiated from the light source array210A to evenly supply the scattered and diffused light to a living body such as a skin.

The bio imaging system100may be applied to an electronic device such as a medical or security imaging device for identifying spatial information of the internal tissues of the living body, and this spatial information may be obtained temporarily or in real time. For example, the internal tissues of the living body may be blood vessels or internal organs, and the spatial information such as a location, shape, size and/or thickness of the blood vessels or internal organs may be used to predict or treat vascular diseases or diseases of internal organs in advance.

The bio imaging system100may be, for example, a wearable bio imaging system or a skin-attachable bio imaging system directly attached to the skin, and the skin-attachable bio imaging system may be, for example, a patch-type bio imaging system or a band-type bio imaging system.

The bio imaging system100may further include a driving unit such as an IC and a processor for obtaining an electrical signal as described above and separating and/or extracting spatial information of an internal tissue of the living body according to the electrical signal.

The bio imaging system100may further include a display unit for displaying images and spatial information of the internal tissue of the living body as various characters and/or images.

FIG.34is a schematic diagram of an electronic device1300according to some example embodiments. The electronic device1300shown inFIG.34may be an electronic device according to any of the example embodiments.

Referring toFIG.34, an electronic device1300includes a processor1320, a memory1330, a sensor1340, and a display device1350electrically connected through a bus1310. The sensor1340may include the bio imaging system100according to any of the example embodiments. The display device1350may include a display panel, for example an OLED display panel. In the example embodiments shown inFIG.34, the electronic device1300may include both a sensor1340and a display device1350, but example embodiments are not limited thereto: in some example embodiments the electronic device1300may include one of the sensor1340or the display device1350.

In some example embodiments, some or all of the electronic device1300may include or be included in a bio imaging system100according to any of the example embodiments. For example, in some example embodiments, the electronic device1300may include a bio imaging system100according to any of the example embodiments that includes and/or is included in at least one of the sensor1340or the display device1350, and the memory1330, processor1320, and bus1310may be on the substrate110of the bio imaging system100and coupled to one or more electrodes of the bio imaging system100. In some example embodiments, the bio imaging system100may be limited to the sensor1340and/or display device1350included in the electronic device1300, wherein the bus1310, memory1330, and processor1320are external to the bio imaging system100and coupled thereto (e.g., via bus1310) to establish the electronic device1300.

The processor1320may perform a memory program and thus at least one function, including controlling the sensor1340and/or displaying an image on the display device1350. The processor1320may generate an output.

As described herein, any devices, systems, electronic devices, blocks, modules, units, controllers, circuits, and/or portions thereof according to any of the example embodiments, and/or any portions thereof (including, without limitation, bio imaging system100, controller101, electronic device1300, processor1320, memory1330, sensor1340, display device1350, or the like) may include, may be included in, and/or may be implemented by one or more instances of processing circuitry such as hardware including logic circuits; a hardware/software combination such as a processor executing software; or a combination thereof. For example, the processing circuitry more specifically may include, but is not limited to, a central processing unit (CPU), an arithmetic logic unit (ALU), a graphics processing unit (GPU), an application processor (AP), a digital signal processor (DSP), a microcomputer, a field programmable gate array (FPGA), and programmable logic unit, a microprocessor, application-specific integrated circuit (ASIC), a neural network processing unit (NPU), an Electronic Control Unit (ECU), an Image Signal Processor (ISP), and the like. In some example embodiments, the processing circuitry may include a non-transitory computer readable storage device (e.g., a memory), for example a solid state drive (SSD), storing a program of instructions, and a processor (e.g., CPU) configured to execute the program of instructions to implement the functionality and/or methods performed by some or all of any devices, systems, electronic devices, blocks, modules, units, controllers, circuits, and/or portions thereof according to any of the example embodiments, and/or any portions thereof.

Any of the memories and/or storage devices described herein, including, without limitation, memory1330, or the like, may be a non-transitory computer readable medium and may store a program of instructions. Any of the memories described herein may be a nonvolatile memory, such as a flash memory, a phase-change random access memory (PRAM), a magneto-resistive RAM (MRAM), a resistive RAM (ReRAM), or a ferro-electric RAM (FRAM), or a volatile memory, such as a static RAM (SRAM), a dynamic RAM (DRAM), or a synchronous DRAM (SDRAM).

Referring to at leastFIGS.25,26,27A-27B,28,29, and30, the bio imaging system100may include a controller101that may be configured to perform some or all of any of the methods described herein with regard to any of the example embodiments. The controller101may, for example, include one or more instances of processing circuitry as described herein, which may include a memory (e.g., memory1330) that stores a program of instructions and a processor (e.g., processor1320) that is configured to execute the program of instructions to cause the bio imaging system100to perform some or all of any of the methods as described herein according to any of the example embodiments.

For example, the controller101may be configured to control the light source210according to any example embodiments to cause the light source210to emit light as described herein according to any example embodiments to irradiate a skin of a living body. Where the light source210includes a plurality of light sources, for example light sources configured to emit light of different emission spectra within visible to infrared wavelength spectra, the controller101may control the light source210(e.g., via transmitting particular signals and/or voltages to the light source210) to cause the various light sources thereof to sequentially emit light. As described herein, the emitted light may be scattered and/or reflected by internal tissue of the living body, and the sensor220may absorb such scattered and/or reflected light based on the emitted light irradiating the skin of the living body. The sensor220may generate one or more signals based on absorbing the light. The one or more signals may be received at the controller101from the sensor220and processed by the controller101to obtain (e.g., generate) a plurality of images (e.g., a plurality of images of the internal tissue based on light of different wavelength spectra) as described herein according to any example embodiments. The controller101may be configured to extract differences between the plurality of images to generate a plurality of extracted images of the internal tissue of the living body according to a depth from a skin surface of the skin, as described herein according to any example embodiments. Such extraction may include extracting a first image of an internal tissue of the living body located at a first depth from the skin surface based on processing the obtained images to determine a difference between an image generated based on causing a second light source of the light sources to emit light and an image generated based on causing a first light source of the light sources to emit light, and extracting a second image of the internal tissue of the living body located at a second depth deeper than the first depth based on a difference between an image generated based on causing a third light source of the light sources to emit light and the image generated based on causing the second light source to emit light. Where the sensor220includes multiple sensors (e.g., first, second, and third sensors) configured to absorb light of different absorption spectra in relation to each other, the extracting differences between the plurality of images may include extracting a first image of the internal tissue of the living body located at a first depth from the skin surface based on a difference between an image generated based on the second sensor absorbing light and an image generated based on the first sensor absorbing light, and extracting a second image of the internal tissue of the living body located at a second depth deeper than the first depth based on a difference between an image generated based on the third sensor absorbing light and the image generated based on the second sensor absorbing light. The controller101may configured to generate a three-dimensional image of the internal tissue of the living body based on combining the plurality of extracted images as described herein according to any of the example embodiments. The controller101may be configured to, prior to generating the three-dimensional image, generate a correction image from a portion of the light source or a portion of the sensor, and correct the plurality of extracted images using the correction image. The controller101may then generate the three-dimensional image based on combining the corrected extracted images. Obtained and/or generated images may be output, displayed, transmitted, or the like (e.g., on a display device as described herein). The controller101may obtain information image information of an internal tissue of a living body according to any of the methods of any of the example embodiments based on obtained (e.g., generated) images, including extracted and/or three-dimensional images as described herein, and may cause such information to be output, transmitted, displayed, etc.

Hereinafter, some example embodiments are illustrated in more detail with reference to examples. However, the scope of the inventive concepts is not limited to these examples.

Optical Simulation

Example 1

Each blood vessel image is evaluated when a plurality of blood vessels are distributed along the depth direction by using a bio imaging system.

Simulation conditions are as follows.Bio imaging system having the structures shown inFIGS.3to5DStretchable substrate thickness: 0.02 mmDistribution of 3 blood vessels BV1, BV2and BV3according to depthLight source: surface light source (Lambertian)Maximum emission wavelength of first, second, and third light sources: 600 nm/700 nm/800 nmFull width at half maximum (FWHM) of emission spectra of first, second, and third light sources: 100 nm/100 nm/100 nmUpper electrode/lower electrode of light source (light emitting element): reflecting electrode/light-transmitting electrodeInternal quantum efficiency of the lower and upper light absorption elements is assumed to be 100%Skin composition: skin thickness of 1.5 mm, fat thickness of 3 mm, muscle thickness of 30 mm,Information of upper blood vessel (BV1): x=0 mm (ref.), z=1.5 mm (depth from skin surface), radius of 0.5 mm,Information of middle blood vessel (BV2): x=4 mm, z=5 mm (depth from skin surface), radius of 1.5 mm,Information of lower blood vessel (BV3): x=−3 mm, z=6 mm (depth from skin surface), radius of 1.0 mm,

The results are shown inFIGS.31A,31B, and31C.

FIGS.31A,31B, and31Care simulation graphs predicting the distribution of each blood vessel, when a plurality of blood vessels are distributed along the depth direction, using the bio imaging system according to Example 1.

When light is irradiated to the skin, light at a wavelength of 800 nm (first light source) and light at a wavelength of 700 nm (second light source) may reach each different depth of about 7 mm and 4 mm, and since a difference of images obtained from the first and second light sources, as shown inFIG.31A, includes information of a depth section ranging from 4 mm to 7 mm, there is composed of two peak signals from the blood vessel BV2and the lower vessel BV3. A skin light-scattering distribution (a correction value) is extracted, as shown inFIG.31C, and then, applied toFIG.31Ato predict signals of the intermediate blood vessel BV2, which are the same as the extraction result ofFIG.31B. Compared with ideal data obtained from input data of the simulation (input simulation of theFIG.31B), the signals are almost identical therewith. Accordingly, an image with a wavelength difference and a correction value by a skin light-scattering distribution may be used to relatively accurately extract specific blood vessels among a plurality of blood vessels overlapped in a depth direction.

Observation of Blood Vessel Image

Example 2

A bio imaging system including a wavelength-tunable light emitting element as a light source is attached to the back of a hand to examine a blood vessel image.

FIG.32is a graph showing a signal according to the depth of a living body obtained using the bio imaging system according to Example 2, andFIG.33is a graph showing signals for each wavelength measured in four pixels ofFIG.32.

Referring toFIG.32, the bio imaging system including a wavelength-tunable light emitting element (550 nm to 650 nm) as a light source in which blood vessels are distributed is attached to the back of the hand to irradiate light and transmit the light scattered and reflected by the blood vessels and then, measure it in four different pixels at different positions p1, p2, p3, and p4. The blood vessels are disposed to be overlapped with the 3rdpixel p3and the 4thpixel p4. Since the light irradiated from the light source reaches a different depth depending on a wavelength, an image “A” measured at the pixels p1, p2, p3, and p4may be obtained from a difference between data obtained by using a light source of a wavelength of 550 nm and data obtained by using a light source of a wavelength of 500 nm. Likewise, an image “B” measured in the pixels p1, p2, p3, and p4may be obtained from a difference between data obtained by using a light source of a wavelength of 600 nm and data obtained by using a light source of a wavelength of 550 nm. Similarly, an image “C” measured in the pixels p1, p2, p3, and p4may be obtained from a difference between data obtained by using a light source of a wavelength of 650 nm and data obtained by using a light source of a wavelength of 600 nm. The images “A”, “B”, and “C” are displayed in colors based on the same scale bar, wherein the image “A” represents depth information between 0.6 mm to 0.3 mm from the skin surface, the image “B” represents depth information between 1.2 mm to 0.6 mm from the skin surface, and the image “B” represents depth information between 2.3 mm to 1.2 mm from the skin surface. Considering that high signals are detected at the two pixels p3and p4of the image “B”, blood vessels located at a specific position and depth are surely detected.

FIG.33shows a signal depending on a wavelength measured in the four pixels p1, p2, p3, and p4, which are shown inFIG.32, and as described above, a high signal at a depth (550 nm/600 nm) of 1.2 mm and 0.6 mm is detected in the two pixels p3and p4. The signals (S) obtained at this time may be obtained by correcting an actually-measured value (Sm(λ)) with a skin light-scattering distribution (S0(λ), correction value) measured at a position where there are no blood vessels (e.g., p1and p2).

While the inventive concepts have been described in connection with what is presently considered to be practical example embodiments, it is to be understood that the inventive concepts are not limited to the these example embodiments. On the contrary, the scope of the inventive concepts is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.