Spectroscopic filter, image sensor containing the same, and electronic device
The spectroscopic filter design with symmetrical Bragg reflection layers and resonant layers in image sensors addresses the challenge of miniaturization by enabling broadband filtering and efficient wavelength transmission, supporting the integration of optical elements and integrated circuits on semiconductor chips.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2021-10-25
- Publication Date
- 2026-03-25
AI Technical Summary
Conventional image sensors using spectroscopic filters are large in volume and heavy, posing challenges for miniaturization efforts in integrating optical elements and integrated circuits on semiconductor chips.
A spectroscopic filter design incorporating a first and second Bragg reflection layer symmetrical to a first resonant layer, with a second resonant layer between them, and a third and fourth Bragg reflection layer symmetrical to a second resonant layer, each with different material layer thicknesses, allowing for multiple band filters sharing a cavity to achieve broadband characteristics.
The design enables a broadband characteristic by including multiple band filters with different reflection wavelength bands, enhancing the ability to block unwanted wavelength bands while transmitting specific wavelengths, thus supporting miniaturization of image sensors.
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Abstract
Description
Technical Field
[0001] The present invention relates to a spectroscopic filter, an image sensor including the same, and an electronic device.
Background Art
[0002] An image sensor using a spectroscopic filter is one of important optical instruments in the optical field. Conventional image sensors include various optical elements and are large in volume and heavy. Recently, due to the requirement for miniaturization of image sensors, research has been underway to simultaneously embody integrated circuits and optical elements on one semiconductor chip.
Summary of the Invention
Problems to be Solved by the Invention
[0003] The problem to be solved by the present invention is to provide a spectroscopic filter, an image sensor including the same, and an electronic device.
Means for Solving the Problems
[0004] A spectroscopic filter according to an embodiment includes a first resonance layer including a cavity; a first Bragg reflection layer and a second Bragg reflection layer disposed apart from each other with the first resonance layer interposed therebetween; a second resonance layer including at least a part of the first Bragg reflection layer and the second Bragg reflection layer and the cavity; and a third Bragg reflection layer and a fourth Bragg reflection layer disposed apart from each other with the second resonance layer interposed therebetween.
[0005] Each of the first Bragg reflection layer to the fourth Bragg reflection layer may have a structure in which a plurality of material layers having different refractive indices are laminated with each other.
[0006] Each of the first Bragg reflection layer to the fourth Bragg reflection layer may include a distributed Bragg reflector (DBR).
[0007] Furthermore, the first Bragg reflective layer and the second Bragg reflective layer are symmetrical with respect to the first resonant layer.
[0008] Furthermore, the third Bragg reflective layer and the fourth Bragg reflective layer are symmetrical with respect to the second resonant layer.
[0009] Furthermore, the thicknesses of the material layers contained in the first Bragg reflective layer and the second Bragg reflective layer are different from the thicknesses of the material layers contained in the third Bragg reflective layer and the fourth Bragg reflective layer.
[0010] Furthermore, the thickness of the material layers included in the first Bragg reflective layer and the second Bragg reflective layer is thinner than the thickness of the material layers included in the third Bragg reflective layer and the fourth Bragg reflective layer.
[0011] Furthermore, the second resonant layer may include the first Bragg reflector and the second Bragg reflector.
[0012] Furthermore, the first surfaces of the first Bragg reflective layer and the second Bragg reflective layer can be in contact with the first resonant layer.
[0013] Furthermore, the second surfaces of the first Bragg reflective layer and the second Bragg reflective layer, which face each of the first surfaces, can come into contact with the third Bragg reflective layer and the fourth Bragg reflective layer.
[0014] Furthermore, the second resonant layer may include only one of the first Bragg reflective layer and the second Bragg reflective layer.
[0015] Furthermore, only one of the first Bragg reflective layer and the second Bragg reflective layer may be in contact with the first resonant layer.
[0016] Furthermore, the remaining layer of the first Bragg reflective layer and the second Bragg reflective layer may be spaced apart from the first resonant layer, with either the third Bragg reflective layer or the fourth Bragg reflective layer in between.
[0017] Furthermore, the wavelength of the wave transmitted through the spectral filter is also determined by at least one of the effective refractive index of the cavity and the thickness of the cavity.
[0018] Furthermore, the spectral filter may include a first unit filter through which light of a first wavelength is transmitted, and a second unit filter through which light of a second wavelength different from the first wavelength is transmitted.
[0019] Furthermore, the effective refractive index of the cavity included in the first unit filter and the effective refractive index of the cavity included in the second unit filter are different from each other.
[0020] Furthermore, the material pattern of the cavity contained in the first unit filter and the material pattern of the cavity contained in the second unit filter are different from each other.
[0021] Furthermore, the spectral filter may further include a plurality of microlenses provided in the at least one first unit filter and the second unit filter.
[0022] Furthermore, the spectral filter may further include the at least one first unit filter and the second unit filter, and a color filter arranged on the same plane.
[0023] Furthermore, the spectral filter may further include an additional filter provided in at least one first unit filter and a second unit filter that transmits only a specific wavelength band.
[0024] Note that an image sensor according to an embodiment includes a spectroscopic filter and a pixel array that receives light transmitted through the spectroscopic filter. The spectroscopic filter includes a first resonant layer including a cavity; a first Bragg reflector and a second Bragg reflector that are spaced apart from each other with the first resonant layer interposed therebetween; a second resonant layer including at least a part of the first Bragg reflector and the second Bragg reflector and the cavity; and a third Bragg reflector and a fourth Bragg reflector that are spaced apart from each other with the second resonant layer interposed therebetween.
[0025] Each of the first Bragg reflector to the fourth Bragg reflector may include a distributed Bragg reflector (DBR).
[0026] In addition, the thickness of the material layers included in the first Bragg reflector and the second Bragg reflector may be different from the thickness of the material layers included in the third Bragg reflector and the fourth Bragg reflector.
[0027] The second resonant layer may include the first Bragg reflector and the second Bragg reflector.
[0028] In addition, each first surface of the first Bragg reflector and the second Bragg reflector is in contact with the first resonant layer, and each second surface of the first Bragg reflector and the second Bragg reflector facing each first surface may be in contact with the third Bragg reflector and the fourth Bragg reflector.
[0029] The second resonant layer may include only any one of the first Bragg reflector and the second Bragg reflector.
[0030] In addition, only any one of the first Bragg reflector and the second Bragg reflector may be in contact with the first resonant layer.
[0031] The spectroscopic filter may further include a plurality of microlenses provided in the at least one first unit filter and second unit filter.
[0032] Furthermore, the spectral filter may further include the at least one first unit filter and the second unit filter, and a color filter arranged on the same plane.
[0033] Furthermore, the spectral filter may further include an additional filter provided in the at least one first unit filter and the second unit filter that transmits only a specific wavelength band.
[0034] The image sensor may further include a timing controller, a low decoder, and an output circuit.
[0035] An electronic device including the aforementioned image sensor is provided.
[0036] The aforementioned electronic devices may include mobile phones, smartphones, tablets, smart tablets, digital cameras, camcorders, notebook computers, televisions, smart televisions, smart refrigerators, security cameras, robots, or medical cameras. [Effects of the Invention]
[0037] According to the present invention, a broadband characteristic can be achieved by including multiple band filters with different reflection wavelength bands while the spectral filter shares a cavity.
[0038] According to the present invention, an image sensor including the aforementioned spectral filter may also be provided, and an electronic device including the image sensor may also be provided. [Brief explanation of the drawing]
[0039] [Figure 1] This is a block diagram of an image sensor according to an exemplary embodiment. [Figure 2] Figure 1 shows a cross-section of a unit filter included in the spectral filter. [Figure 3] This diagram illustrates a unit filter according to another embodiment. [Figure 4] This figure illustrates a unit filter according to another embodiment. [Figure 5] This figure illustrates a spectral filter that transmits light of different wavelengths according to one embodiment. [Figure 6] This figure illustrates a cross-section of a spectral filter according to another exemplary embodiment. [Figure 7] This is a schematic cross-sectional view illustrating a spectral filter according to another exemplary embodiment. [Figure 8] This is a schematic cross-sectional view illustrating a spectral filter according to another exemplary embodiment. [Figure 9] This is a schematic cross-sectional view illustrating a spectral filter according to another exemplary embodiment. [Figure 10] This diagram illustrates examples of spectral filters that can be used as additional filters. [Figure 11] This diagram illustrates other examples of spectral filters that can be used as additional filters. [Figure 12] This is a schematic cross-sectional view illustrating a spectral filter according to another exemplary embodiment. [Figure 13] This is an illustrative plan view of a spectral filter that may be applied to the image sensor shown in Figure 1. [Figure 14] This is another exemplary plan view of a spectral filter that may be applied to the image sensor shown in Figure 1. [Figure 15] This is yet another illustrative plan view of a spectral filter that may be applied to the image sensor shown in Figure 1. [Figure 16] This is a schematic block diagram illustrating an electronic device including an image sensor according to an exemplary embodiment. [Figure 17] This is a block diagram illustrating the camera module shown in Figure 16. [Figure 18] This figure shows various examples of electronic devices to which an image sensor according to an exemplary embodiment is applied. [Figure 19]This figure shows various examples of electronic devices to which an image sensor according to an exemplary embodiment is applied. [Figure 20] This figure shows various examples of electronic devices to which an image sensor according to an exemplary embodiment is applied. [Figure 21] This figure shows various examples of electronic devices to which an image sensor according to an exemplary embodiment is applied. [Figure 22] This figure shows various examples of electronic devices to which an image sensor according to an exemplary embodiment is applied. [Figure 23] This figure shows various examples of electronic devices to which an image sensor according to an exemplary embodiment is applied. [Figure 24] This figure shows various examples of electronic devices to which an image sensor according to an exemplary embodiment is applied. [Figure 25] This figure shows various examples of electronic devices to which an image sensor according to an exemplary embodiment is applied. [Figure 26] This figure shows various examples of electronic devices to which an image sensor according to an exemplary embodiment is applied. [Figure 27] This figure shows various examples of electronic devices to which an image sensor according to an exemplary embodiment is applied. [Modes for carrying out the invention]
[0040] The following describes exemplary embodiments in detail with reference to the attached drawings. In the following drawings, the same reference numerals refer to the same components, and the size of each component in the drawings is exaggerated for clarity and ease of explanation. The embodiments described below are merely illustrative, and various modifications are possible from such embodiments.
[0041] In the following, "top" or "above" may include not only things that are directly above and in contact with the object, but also things that are above but not in contact with the object. Singular expressions include plural expressions unless the context clearly indicates otherwise. Also, when a part "includes" a component, it does not mean that other components are excluded, but rather that other components may be included, unless otherwise specified.
[0042] The use of the term "the foregoing" and similar referential terms can be singular or plural. Unless explicitly stated otherwise, the steps constituting a method shall be performed in an appropriate order, and not necessarily limited to the order stated.
[0043] Furthermore, terms such as "...part" and "module" as used in the specification refer to units that perform at least one function or operation, which are embodied by hardware or software, or by a combination of hardware and software.
[0044] The linear connections or connecting members between components shown in the drawings exemplify functional and / or physical or circuit connections, and in actual devices, they may also be shown as a variety of interchangeable or additional functional, physical, or circuit connections.
[0045] All use of examples or illustrative terms is solely for the purpose of illustrating the technical idea in detail and is not limited by the scope of the claims unless otherwise specified.
[0046] Figure 1 is a schematic block diagram of an image sensor according to an exemplary embodiment.
[0047] Referring to Figure 1, the image sensor 10 may include a spectral filter 11, a pixel array 12, a timing controller 13, a row decoder 14, and an output circuit 15. The image sensor may include, but is not limited to, a CCD (charge coupled device) image sensor or a CMOS (complementary metal oxide semiconductor) image sensor.
[0048] The spectral filter 11 transmits light in different wavelength regions and includes a plurality of unit filters arranged in two dimensions. The pixel array 12 includes a plurality of pixels that sense light of different wavelengths that have passed through the plurality of unit filters. Specifically, the pixel array 12 includes pixels arranged in two dimensions along a plurality of rows and columns. The row decoder 14 selects one row of the pixel array 12 in response to a row address signal output from the timing controller 13. The output circuit 15 outputs a light sensing signal from the plurality of pixels arranged along the selected row, on a column-by-column basis. To this end, the output circuit 15 may include a column decoder and an analog-to-digital converter (ADC). For example, the output circuit 15 may include a plurality of analog-to-digital converters (ADCs) arranged column by column between the column decoder and the pixel array 12, or a single analog-to-digital converter (ADC) arranged at the output terminal of the column decoder. The timing controller 13, row decoder 14, and output circuit 15 can also be implemented as a single chip or as separate chips. A processor for processing the video signal output via the output circuit 15 is also implemented on a single chip, along with the timing controller 13, the low decoder 14, and the output circuit 15. The pixel array 12 includes multiple pixels that sense light of different wavelengths, and the arrangement of these pixels can also be implemented in various ways.
[0049] The spectral filters of image sensors will be described in detail below.
[0050] Figure 2 is a cross-sectional view illustrating the unit filter included in the spectral filter shown in Figure 1.
[0051] The unit filter 100 may include a cavity C, a first band filter 110 including the cavity C, and a second band filter 120. The first band filter 110 and the second band filter 120 share the cavity C and can transmit light of a specific wavelength determined by the cavity C, while blocking light of wavelengths other than the specific wavelength.
[0052] The first bandfilter 110 and the second bandfilter 120 each have a Fabry-Perot structure in which a resonant layer is provided between two reflective layers, allowing light having a specific center wavelength to pass through. Here, the center wavelength and wavelength band of the light passing through the bandfilter can be determined by the reflection band of the reflective layer and the characteristics of the resonant layer.
[0053] The first band filter 110 and the second band filter 120 can block light of different wavelengths from each other. A unit filter 100 according to one embodiment includes a plurality of band filters, namely the first band filter 110 and the second band filter 120, which share a cavity C and block light of different wavelength bands from each other, but can block light of different optical bands.
[0054] The first bandpass filter 110 may include a first resonant layer R1 containing a cavity C, a first Bragg reflector DBR1, and a second Bragg reflector DBR2 spaced apart on either side of the first resonant layer R1. The first Bragg reflector DBR1 and the second Bragg reflector DBR2 can also function as distributed Bragg reflectors (DBRs). The first Bragg reflector DBR1 and the second Bragg reflector DBR2 may have a symmetrical structure with respect to the first resonant layer R1.
[0055] The first resonant layer R1 includes only the cavity C and may be in contact with the first Bragg reflector layer DBR1 and the second Bragg reflector layer DBR2. For example, the first Bragg reflector layer DBR1 may be in contact with the upper surface of the cavity C, and the second Bragg reflector layer DBR2 may be in contact with the lower surface of the cavity C. Cavity C may contain a dielectric material having a predetermined refractive index. For example, cavity C may contain silicon, silicon oxide, or titanium oxide.
[0056] The effective refractive index of cavity C may include a material with a refractive index lower than that of the first Bragg reflective layer DBR1 and the second Bragg reflective layer DBR2. For example, cavity C may be made of SiO2 (refractive index = 1.46). However, this is merely an example, and cavity C may be made of a variety of other materials depending on design conditions such as the wavelength of incident light.
[0057] The first Bragg reflective layer DBR1 and the second Bragg reflective layer DBR2 may each have a structure in which a first material layer 161a and a second material layer 161b of predetermined thickness, each having different refractive indices, are laminated together. However, the structure is not limited to this, and the first Bragg reflective layer DBR1 and the second Bragg reflective layer DBR2 may also have a structure in which three or more material layers, each having different refractive indices, are laminated together.
[0058] The first material layer 161a and the second material layer 161b may each contain, for example, silicon oxide and titanium oxide. For example, the first material layer 161a and the second material layer 161b may each contain, for example, silicon oxide and silicon. However, these are merely illustrative examples, and the first material layer 161a and the second material layer 161b may also contain a variety of other materials. Silicon has a refractive index of approximately 3.0 or higher, silicon oxide has a refractive index of approximately 1.4 to 1.5, and titanium oxide may have a refractive index of approximately 1.9 to 3.0.
[0059] When light passes through the first Bragg reflective layer DBR1 and enters the first resonant layer R1, the light travels back and forth within the first resonant layer R1 between the first Bragg reflective layer DBR1 and the second Bragg reflective layer DBR2, causing reinforcing interference and canceling interference in the process. Then, light having a specific center wavelength that satisfies the reinforcing interference condition is emitted to the outside of the first bandfilter 110.
[0060] In addition, the unit filter 100 according to one embodiment may further include a second band filter 120 that shares the cavity C of the first band filter 110. Specifically, the second band filter 120 may include a second resonant layer R2 that includes at least a portion of the first Bragg reflective layer DBR1 and the second Bragg reflective layer DBR2 and the cavity C, and a third Bragg reflective layer DBR3 and a fourth Bragg reflective layer DBR4 that are spaced apart with the second resonant layer R2 in between.
[0061] The second resonant layer R2 includes the cavity C of the first bandfilter 110 and may include at least a portion of the first Bragg reflector layer DBR1 and the second Bragg reflector layer DBR2 of the first bandfilter 110. For example, as shown in Figure 2, the second resonant layer R2 may include the cavity C, the first Bragg reflector layer DBR1, and the second Bragg reflector layer DBR2.
[0062] The third Bragg reflector DBR3 and the fourth Bragg reflector DBR4 can also function as dispersed Bragg reflectors (DBRs). The third Bragg reflector DBR3 and the fourth Bragg reflector DBR4 may have a symmetrical structure with respect to the second resonant layer R2.
[0063] The third Bragg reflective layer DBR3 and the fourth Bragg reflective layer DBR4 may each have a structure in which a third material layer 171a and a fourth material layer 171b of predetermined thickness, each having different refractive indices, are laminated together. However, the structure is not limited to this, and the third Bragg reflective layer DBR3 and the fourth Bragg reflective layer DBR4 may also have a structure in which three or more material layers, each having different refractive indices, are laminated together.
[0064] The third material layer 171a and the fourth material layer 171b may each contain, for example, the same materials as the first material layer 161a and the second material layer 161b described above. However, they are not limited to this. For example, the third material layer 171a and the fourth material layer 171b may each contain silicon oxide and titanium oxide, respectively. To give another example, the third material layer 171a and the fourth material layer 171b may each contain, for example, silicon oxide and silicon. However, this is merely illustrative, and the third material layer 171a and the fourth material layer 171b may also contain a variety of other materials.
[0065] The second band filter 120 may have a reflection wavelength band different from that of the first band filter 110. For example, the second band filter 120 includes a third material layer 171a and a fourth material layer 171b, and at least one of the materials and thicknesses of the third material layer 171a and the fourth material layer 171b may differ from the materials and thicknesses of the first material layer 161a and the second material layer 161b. For example, if the third material layer 171a and the fourth material layer 171b are identical to the first material layer 161a and the second material layer 161b, respectively, then the third material layer 171a and the fourth material layer 171b may have different thicknesses from the first material layer 161a and the second material layer 161b. However, it is not limited to this, and the third material layer 171a and the fourth material layer 171b may contain materials different from those of the first material layer 161a and the second material layer 161b. In that case, the third material layer 171a and the fourth material layer 171b may have thicknesses similar to the first material layer 161a and the second material layer 161b, respectively, or they may have different thicknesses.
[0066] Figure 2 illustrates an example where the third material layer 171a and the fourth material layer 171b included in the second band filter 120 have different thicknesses from the first material layer 161a and the second material layer 161b included in the first band filter 110, thereby realizing different reflection wavelength bands.
[0067] As explained above, the unit filter 100 has multiple band filters, each containing different reflection wavelength bands, that share cavity C. Therefore, compared to filtering light with a single band filter, the unit filter 100 can further enhance its ability to block wavelength bands corresponding to sidebands other than the central wavelength.
[0068] Specifically, when light is incident on the unit filter 100, a portion of the light travels back and forth within the second bandfilter 120, i.e., the second resonant layer R2 between the third Bragg reflective layer DBR3 and the fourth Bragg reflective layer DBR4, causing reinforcement and cancellation interference in the process. In addition, another portion of the light travels back and forth within the first bandfilter 110, i.e., the first resonant layer R1 between the first Bragg reflective layer DBR1 and the second Bragg reflective layer DBR2, causing reinforcement and cancellation interference in the process. Light having a specific center wavelength that satisfies the reinforcement interference condition is emitted outside the first bandfilter 110. This light causes reinforcement and cancellation interference in the second bandfilter 120 and the first bandfilter 110, but the filtered wavelength band is also broadened.
[0069] Figure 3 is a diagram illustrating a unit filter according to another embodiment. As shown in Figure 3, the unit filter 100a includes a third resonant layer R3 including a cavity C, and a first Bragg reflective layer DBR1 and a second Bragg reflective layer DBR2 spaced apart on either side of the cavity C, and a third band filter 130. The unit filter 100a may further include a fourth resonant layer R4 including a portion of the aforementioned first Bragg reflective layer DBR1 and second Bragg reflective layer DBR2 and the cavity C, and a fourth band filter 140 including a third Bragg reflective layer DBR3 and a fourth Bragg reflective layer DBR4 spaced apart on either side of the fourth resonant layer R4.
[0070] In Figure 3, the third resonant layer R3 is shown to include a cavity C and a third Bragg reflector DBR3, and the fourth resonant layer R4 is shown to include a cavity C and a second Bragg reflector DBR2. The upper surface of cavity C is in contact with the third Bragg reflector DBR3, the lower surface of cavity C is in contact with the second Bragg reflector DBR2, the upper surface of the third Bragg reflector DBR3 is in contact with the first Bragg reflector DBR1, and the lower surface of the second Bragg reflector DBR2 may be in contact with the fourth Bragg reflector.
[0071] The first Bragg reflective layer DBR1 and the second Bragg reflective layer DBR2 have a symmetrical structure with respect to the third resonant layer R3, while the third Bragg reflective layer DBR3 and the fourth Bragg reflective layer DBR4 also have a symmetrical structure with respect to the fourth resonant layer R4.
[0072] The unit filter in Figure 3 also shares a cavity, resulting in a wider filtering bandwidth.
[0073] Figure 4 is a diagram illustrating a unit filter according to yet another embodiment. As shown in Figure 4, the unit filter 100b may include a cavity C, a fifth band filter 150 including the cavity C, and a sixth band filter 160. The fifth band filter 150 and the sixth band filter 160 share the cavity C and can transmit light of a specific wavelength determined by the cavity C, while blocking light of wavelengths other than the specific wavelength.
[0074] The fifth bandfilter 150 and the sixth bandfilter 160 have a Fabry-Perot structure in which a resonant layer is provided between two reflective layers, allowing light having a specific center wavelength to pass through. Here, the center wavelength and wavelength band of the light passing through the bandfilter can be determined by the reflection band of the reflective layer and the characteristics of the resonant layer.
[0075] The fifth band filter 150 may also include a fifth resonant layer R5 containing a cavity C, and a first metal reflective layer M1 and a second metal reflective layer M2 spaced apart on either side of the fifth resonant layer R5.
[0076] The first metal reflective layer M1 and the second metal reflective layer M2 may each contain a metal capable of reflecting light in the first wavelength region. For example, the metal may include Al, Ag, Au, or TiN, but is not limited to these. Such first and second metal reflective layers M1 and M2 can be provided with a thickness of several tens of nanometers, but this is merely illustrative. As a specific example, the first and second metal reflective layers M1 and M2 may have a thickness of approximately 10 nm to 30 nm.
[0077] The cavity C provided between the first metal reflective layer M1 and the second metal reflective layer M2 may contain a dielectric material having a predetermined refractive index as the fifth resonant layer R5. For example, cavity C may contain silicon, silicon oxide, silicon nitride, hafnium oxide, or titanium oxide, but is not limited to these.
[0078] The sixth band filter 160 may include a sixth resonant layer R6 which includes at least a portion of the fifth band filter 150, and a fifth reflective layer DBR5 and a sixth Bragg reflective layer DBR6 which are spaced apart with respect to the sixth resonant layer R6.
[0079] The sixth resonant layer R6 includes the cavity C of the fifth bandfilter 140 and may include at least a portion of the first metal reflective layer M1 and the second metal reflective layer M2 of the fifth bandfilter 140. For example, as shown in Figure 4, the sixth resonant layer R6 may include any of the cavity C, the first metal reflective layer M1, and the second metal reflective layer M2.
[0080] The fifth reflective layer DBR5 and the sixth Bragg reflective layer DBR6 can also function as dispersed Bragg reflectors (DBRs). The fifth reflective layer DBR5 and the sixth Bragg reflective layer DBR6 may have a symmetrical structure with respect to the sixth resonant layer R6.
[0081] The fifth reflective layer DBR5 and the sixth Bragg reflective layer DBR6 may each have a structure in which multiple material layers of a predetermined thickness, each having a different refractive index, are stacked on top of each other. However, it is not limited to this, and the fifth reflective layer DBR5 and the sixth Bragg reflective layer DBR6 may also have a structure in which three or more material layers, each having a different refractive index, are stacked on top of each other. The Bragg reflective layer has been described above, so a detailed explanation will be omitted.
[0082] When light is incident on the unit filter 100b, some of the light travels back and forth within the sixth resonant layer R6 between the fifth reflective layer DBR5 and the sixth Bragg reflective layer DBR6, causing reinforcing and canceling interference in the process, while other light travels back and forth within the fifth resonant layer R5 between the first metal reflective layer M1 and the second metal reflective layer M2, causing reinforcing and canceling interference in the process. Then, light with a specific center wavelength that satisfies the reinforcing interference conditions is emitted to the outside of the unit filter 100b. Here, the wavelength band and center wavelength of the light passing through the unit filter 100b can be determined by the reflection bands of the first metal reflective layer M1 and the second metal reflective layer M2, the reflection bands of the fifth reflective layer DBR5 and the sixth Bragg reflective layer DBR6, and the characteristics of the cavity C.
[0083] In Figure 4, the sixth band filter 160 is described as including all of the fifth band filter 150, but it is not limited to this. The sixth band filter 160 may include a portion of the fifth band filter 150, and the fifth band filter 150 may also include a portion of the sixth band filter 160. Furthermore, the fifth band filter 150 may include all of the sixth band filter 160. This can be changed by utilizing the unit filter 100b.
[0084] Figure 5 is a diagram illustrating a spectral filter that transmits light of different wavelengths according to one embodiment. As shown in Figure 5, the spectral filter 200 may include a first unit filter 210 and a second unit filter 220. The first unit filter 210 and the second unit filter 220 may each include the first Bragg reflective layer DBR1 to the fourth Bragg reflective layer DBR4 shown in Figure 2. However, compared to Figure 2, the cavity C in Figure 5 may include a first cavity C1 and a second cavity C2 having different effective refractive indices. The effective refractive index also differs depending on the arrangement pattern of the material contained in the cavity C. In the first unit filter 210 and the second unit filter 220, the first Bragg reflective layer DBR1 to the fourth Bragg reflective layer DBR4, excluding the effective refractive index of the cavity C, are identical.
[0085] Cavity C may have a structure in which a fifth material layer 181a and a sixth material layer 181b having different refractive indices are arranged relative to each other. For example, the fifth material layer 181a may contain silicon, and the sixth material layer 181b may contain silicon oxide. However, it is not limited to these, and the fifth material layer 181a and the sixth material layer 181b may contain a variety of other materials.
[0086] For example, the widths of the fifth material layer 181a and the sixth material layer 181b arranged in the first cavity C1 are different from the widths of the fifth material layer 181a and the sixth material layer 181b arranged in the second cavity C2. As a result, the effective refractive index of the first cavity C1 and the effective refractive index of the second cavity C2 are different from each other, and therefore the wavelength of light transmitted through the first cavity C1 and the wavelength of light transmitted through the second cavity C2 are also different from each other.
[0087] Figure 5 illustrates an example where the fifth material layer 181a and the sixth material layer 181b are arranged perpendicular to the first Bragg reflective layer DBR1 to the fourth Bragg reflective layer DBR4. However, it is not limited to this arrangement; the fifth material layer 181a and the sixth material layer 181b may also be arranged in a direction aligned with the first Bragg reflective layer DBR1 to the fourth Bragg reflective layer DBR4, or the fifth material layer 181a and the sixth material layer 181b may be arranged two-dimensionally.
[0088] Figure 6 shows a cross-section of a spectral filter according to another exemplary embodiment. Referring to Figure 6, the spectral filter 300 includes a first filter group 310 and a second filter group 320 arranged on the same plane. The first filter group 310 may include a first unit filter 311, a second unit filter 312, and a third unit filter 313, and the second filter group 320 may include a fourth unit filter 321, a fifth unit filter 322, and a sixth unit filter 323.
[0089] Each of the unit filters 311, 312, and 313 in the first filter group 310 includes a seventh band filter 170 that utilizes cavity C as a resonant layer, and an eighth band filter 180 that utilizes the seventh band filter 170 as a resonant layer. For example, the seventh band filter 170 may include cavity C, and a first Bragg reflector layer DBR1 and a second Bragg reflector layer DBR2 spaced apart with cavity C in between. The eighth band filter 180 may include a third Bragg reflector layer DBR3 and a fourth Bragg reflector layer DBR4 spaced apart with cavity C, the first Bragg reflector layer DBR1 and the second Bragg reflector layer DBR2 in between. The first Bragg reflector layers DBR1 to the fourth Bragg reflector layers DBR4 of the first filter group are the same as the first Bragg reflector layers DBR1 to the fourth Bragg reflector layers DBR4 shown in Figure 2, so a detailed explanation is omitted.
[0090] The first unit filter 311, the second unit filter 312, and the third unit filter 313 may each include a first cavity C11, a second cavity C12, and a third cavity C13.
[0091] The first cavity C11 may have a structure in which a fifth material layer 181a and a sixth material layer 181b having different refractive indices are arranged relative to each other. For example, the fifth material layer 181a may contain silicon, and the sixth material layer 181b may contain silicon oxide. However, it is not limited to these, and the first material layer 181a and the second material layer 181b may contain a variety of other materials.
[0092] Figure 6 illustrates an example where the fifth material layer 181a and the sixth material layer 181b are arranged perpendicular to the first Bragg reflective layer DBR1 to the fourth Bragg reflective layer DBR4. However, it is not limited to this arrangement; the fifth material layer 181a and the sixth material layer 181b may also be arranged in a direction aligned with the first Bragg reflective layer DBR1 to the fourth Bragg reflective layer DBR4, or the fifth material layer 181a and the sixth material layer 181b may be arranged two-dimensionally.
[0093] The second unit filter 312 and the third unit filter 313 of the first filter group 310 are identical to the first unit filter 311 described above, except for the effective refractive index of cavity C. For example, the second cavity C12 of the second unit filter 312 may include a fifth material layer 181a and a sixth material layer 181b with different widths than the first cavity C11, and the third cavity C13 of the third unit filter 313 may include a fifth material layer 181a and a sixth material layer 181b with different thicknesses than the first cavity C11 and the second cavity C12. As a result, the first cavity C11, the second cavity C12, and the third cavity C13 have different effective refractive indices, so that the first unit filter 311, the second unit filter 312, and the third unit filter 313 can transmit only light with different central wavelengths.
[0094] Each of the unit filters 321, 322, and 323 of the second filter group 320 includes a ninth band filter 190 and a tenth band filter 195 that share a cavity C. The ninth band filter 190 can utilize a portion of the tenth band filter 195 as a resonant layer, and the tenth band filter 195 can utilize a portion of the ninth band filter 190 as a resonant layer. For example, the ninth band filter 190 may include a cavity C and a first Bragg reflector layer DBR1 and a second Bragg reflector layer DBR2 spaced apart on either side of the cavity C, while the tenth band filter 195 may include a cavity C and a third Bragg reflector layer DBR3 and a fourth Bragg reflector layer DBR4 spaced apart on either side of the cavity C.
[0095] The ninth bandfilter 190 utilizes either the third Bragg reflective layer DBR3 or the fourth Bragg reflective layer DBR4, for example, the third Bragg reflective layer DBR3 and cavity C as a resonant layer, and the tenth bandfilter 120 can utilize either the first Bragg reflective layer DBR1 or the second Bragg reflective layer DBR2, for example, the second Bragg reflective layer DBR2 and cavity C as a resonant layer. As a result, the second filter group 320 can also be arranged in the order of first Bragg reflective layer DBR1, third Bragg reflective layer DBR3, cavity C, second Bragg reflective layer DBR2, and fourth Bragg reflective layer DBR4.
[0096] The fourth unit filter 321, the fifth unit filter 322, and the sixth unit filter 323 may each include a fourth cavity C21, a fifth cavity C22, and a sixth cavity C23. The fourth cavity C21, the fifth cavity C22, and the sixth cavity C23 may have different effective refractive indices. The fourth cavity C21, the fifth cavity C21, and the sixth cavity C23 may each include a seventh material layer 191a and at least one eighth material layer 191b disposed inside the seventh material layer 191a and having a different refractive index from the seventh material layer 191a.
[0097] Figure 6 illustrates an example in which the fourth cavity C21, the fifth cavity C22, and the sixth cavity C23 each contain a seventh material layer 191a and a plurality of eighth material layers 191b arranged side by side within the seventh material layer 191a. Here, the seventh material layer 191a and the eighth material layer 191b may each contain, for example, silicon, silicon oxide, silicon nitride, or titanium oxide. Specifically, the seventh material layer 191a may contain silicon oxide, and the second material layer 191b may contain titanium oxide.
[0098] The effective refractive index of the fourth cavity C21, fifth cavity C22, and sixth cavity C23 can be changed by adjusting the width of the seventh material layer 191a. Figure 6 illustrates a case where the seventh material layer 191a is provided so that it widens from the fourth cavity C21 to the sixth cavity C23. In this case, of the fourth cavity C21, fifth cavity C22, and sixth cavity C23, the sixth cavity C23 may have the largest effective refractive index, and the fourth cavity C21 may have the smallest effective refractive index. Of the fourth unit filter 321, fifth unit filter 322, and sixth unit filter 323, the sixth unit filter 323 may have the longest center wavelength, and the fourth unit filter 321 may have the shortest center wavelength. In addition, depending on the thickness or effective refractive index of cavity C, some unit filters may have multiple center wavelengths.
[0099] Figure 7 is a schematic cross-sectional view illustrating a spectral filter according to yet another exemplary embodiment.
[0100] Referring to Figure 7, the spectral filter 400 includes a first filter array 410 and a second filter array 420, and a microlens array 460 provided on the first filter array 410 and the second filter array 420. The first filter array 410 may include a first unit filter 411, a second unit filter 412, and a third unit filter 413 having a center wavelength in a first wavelength region, and the second filter array 420 may include a fourth unit filter 421, a fifth unit filter 421, and a sixth unit filter 423 having a center wavelength in a second wavelength region.
[0101] The unit filters included in the first filter array 410 may be any one of the aforementioned unit filters. Further explanation of the first filter array 410 and the second filter array 420 is omitted.
[0102] A microlens array 460, which includes a plurality of microlenses 461, may be provided above the first filter array 410 and the second filter array 420. The microlenses 461 can focus external light onto the corresponding unit filters 411, 412, 413, 421, 422, and 423.
[0103] Figure 7 illustrates an example where the microlens 461 is provided in a one-to-one correspondence with the unit filters 411, 412, 413, 421, 422, and 423. However, this is merely an example, and it is also possible to provide multiple unit filters 411, 412, 413, 421, 422, and 423 corresponding to a single microlens 461.
[0104] Figure 8 is a schematic cross-sectional view illustrating a spectral filter according to yet another exemplary embodiment.
[0105] Referring to Figure 8, the spectral filter 500 includes a first filter array 510, a second filter array 520, and a color filter array 530. Here, the first filter array 510, the second filter array 520, and the color filter array 530 are also provided on substantially the same plane.
[0106] The first filter array 510 may include a first unit filter 511, a second unit filter 512, and a third unit filter 513 having a center wavelength in a first wavelength region, and the second filter array 520 may include a fourth unit filter 521, a fifth unit filter 522, and a sixth unit filter 523 having a center wavelength in a second wavelength region. The unit filters 511, 512, 513, 521, 522, and 523 included in the first filter array 510 and the second filter array 520 may be subject to the aforementioned unit filters.
[0107] The color filter array 530 may include, for example, a red color filter 531, a green color filter 532, and a blue color filter 533. Here, the red color filter 531 can transmit red light having a wavelength band of approximately 600 nm to 700 nm, the green color filter 532 can transmit green light having a wavelength band of approximately 500 nm to 600 nm, and the blue color filter 533 can transmit blue light having a wavelength band of approximately 400 nm to 500 nm. As such red color filter 531, green color filter 532, and blue color filter 533, color filters commonly applied to color display devices such as liquid crystal displays or organic light-emitting displays may be used. A microlens array 560 including a plurality of microlenses 561 may be further provided above the first filter array 510 and the second filter array 520, and the color filter array 530.
[0108] According to this embodiment, not only can information relating to the central wavelengths of unit filters 511, 512, 513, 521, 522, and 523 be obtained by utilizing the first filter array 510 and the second filter array 520, but information relating to the wavelengths of red, green, and blue light can also be obtained by utilizing the color filter array 530.
[0109] Figure 9 is a schematic cross-sectional view illustrating a spectral filter according to yet another exemplary embodiment.
[0110] Referring to Figure 9, the spectral filter 600 includes a first filter array 610 and a second filter array 620, and an additional filter array 660 provided on the first filter array 610 and the second filter array 620. The first filter array 610 may include a first unit filter 611, a second unit filter 612, and a third unit filter 613 having a center wavelength in a first wavelength region, and the second filter array 620 may include a fourth unit filter 621, a fifth unit filter 622, and a sixth unit filter 623 having a center wavelength in a second wavelength region.
[0111] The unit filters included in the first filter array 610 and the second filter array 620 are subject to the aforementioned unit filters, but a detailed explanation will be omitted.
[0112] The additional filter array 660 may include multiple additional filters 661, 662, and 663. Figure 9 illustrates a case where the first additional filter 661 corresponds to the first unit filter 611 and the second unit filter 612, the second additional filter 662 corresponds to the third unit filter 613 and the fourth unit filter 621, and the third additional filter 663 corresponds to the fifth unit filter 622 and the sixth unit filter 623. However, this is merely an example, and each of the first additional filter 661, the second additional filter 662, and the third additional filter 663 can also be configured to correspond to one unit filter 611, 612, 613, 621, 622, or 623, or to correspond to three or more unit filters 611, 612, 613, 621, 622, or 623.
[0113] The first additional filter 661, the second additional filter 662, and the third additional filter 663 can each block light in wavelength bands not desired by the corresponding unit filters 611, 612, 613, 621, 622, and 623. For example, if the first unit filter 611 and the second unit filter 612 have a central wavelength in the wavelength band of approximately 400 nm to 500 nm, the first additional filter 661 also acts as a blue filter that transmits blue light. Similarly, if the third unit filter 613 and the fourth unit filter 621 have a central wavelength in the wavelength band of approximately 500 nm to 600 nm, the second additional filter 662 also acts as a green filter that transmits green light. And if the fifth unit filter 622 and the sixth unit filter 623 have a central wavelength in the wavelength band of approximately 600 nm to 700 nm, the third additional filter 663 also acts as a red filter that transmits red light.
[0114] The additional filter array 660 can also be a color filter array. In this case, the first additional filter 661, the second additional filter 662, and the third additional filter 663 can also be a blue color filter, a green color filter, and a red color filter, respectively. As such blue, green, and red color filters, color filters commonly used in color display devices such as liquid crystal displays or organic light-emitting displays may be used.
[0115] The additional filter array 660 can also be a broadband filter array. In that case, the first additional filter 661, the second additional filter 662, and the third additional filter 663 can also be the first broadband filter, the second broadband filter, and the third broadband filter, respectively. Here, each of the broadband filters may have, for example, a multi-cavity structure or a metal mirror structure.
[0116] Figure 10 illustrates examples of spectral filters that can be used as additional filters.
[0117] Referring to Figure 10, the broadband filter 700 may include a plurality of reflective layers 730, 740, 750 arranged to be spaced apart from each other, and a plurality of cavities 710, 720 provided between the reflective layers 730, 740, 750. Figure 10 illustrates an example with three reflective layers 730, 740, 750 and two cavities 710, 720, but the number of reflective layers 730, 740, 750 and cavities 710, 720 can be varied in many ways.
[0118] Each of the reflective layers 730, 740, and 750 can also function as a dispersed Bragg reflector (DBR). Each of these reflective layers 730, 740, and 750 may have a structure in which multiple material layers having different refractive indices are stacked on top of each other. Each of the cavities 710 and 720 may contain a material having a predetermined refractive index, or may contain two or more materials having different refractive indices.
[0119] Figure 11 illustrates another example of a spectroscopic filter that can be used as an additional filter.
[0120] Referring to Figure 11, the spectroscopic filter 800 may include two metal reflective layers 820, 830 arranged to be spaced apart from each other, and a cavity 810 provided between the metal reflective layers 820, 830. The metal reflective layers 820, 830 may contain metals such as Al, Ag, Au, or TiN, but are not limited to these. Such metal reflective layers 820, 830 may be provided with a thickness of several tens of nanometers, but this is merely illustrative. As a specific example, the metal reflective layers 820, 830 may have a thickness of approximately 10 nm to 30 nm.
[0121] The cavity 810 provided between the metal reflective layers 820 and 830 may contain a dielectric material having a predetermined refractive index. For example, the cavity 810 may contain silicon, silicon oxide, silicon nitride, hafnium oxide, or titanium oxide, but is not limited to these.
[0122] Figure 12 is a schematic cross-sectional view illustrating a spectral filter according to yet another exemplary embodiment.
[0123] Referring to Figure 12, the spectral filter 900 includes a first filter array 910 and a second filter array 920, and a short-wavelength cutoff filter 960 and a long-wavelength cutoff filter 970 provided in the first filter array 910 and the second filter array 920.
[0124] The first filter array 910 may include a first unit filter 911, a second unit filter 912, and a third unit filter 913 having a center wavelength in a first wavelength region, and the second filter array 920 may include a fourth unit filter 921, a fifth unit filter 922, and a sixth unit filter 923 having a center wavelength in a second wavelength region.
[0125] The unit filters 911, 912, 913, 921, 922, and 923 included in the first filter array 910 and the second filter array 920 can be to which the aforementioned unit filters are applied.
[0126] The short-wavelength cutoff filter 960 is also provided on some of the unit filters 911, 913, 921, 922, and 923, specifically on 911, 913, and 922, while the long-wavelength cutoff filter 970 is also provided on other parts of the unit filters 912, 921, and 923. Figure 12 illustrates a case where the short-wavelength cutoff filter 960 and the long-wavelength cutoff filter 970 are provided to correspond to one unit filter 911, 912, 913, 921, 922, and 923, but is not limited to this configuration. The short-wavelength cutoff filter 960 and the long-wavelength cutoff filter 970 can also be provided to correspond to two or more unit filters 911, 912, 913, 921, 922, and 923.
[0127] The short-wavelength blocking filter 960 can, for example, block short-wavelength light such as visible light. Such a short-wavelength blocking filter 960 can also be fabricated by depositing silicon, a material that can absorb visible light, onto parts 911, 913, 921, 922, and 923, specifically parts 911, 913, and 922. Unit filters 911, 913, and 922 equipped with the short-wavelength blocking filter 960 can transmit near-infrared (NIR), which has a longer wavelength than visible light.
[0128] The long-wavelength blocking filter 970 can, for example, block long-wavelength light such as near-infrared light. Such a long-wavelength blocking filter 970 may include a near-infrared blocking filter. Unit filters 912, 921, and 923 equipped with the long-wavelength blocking filter 970 can transmit visible light with wavelengths shorter than near-infrared light.
[0129] According to this embodiment, by providing a short-wavelength cutoff filter 960 and a long-wavelength cutoff filter 970 in the first filter array 910 and the second filter array 920, a spectral filter 900 having broadband characteristics that can realize a range from the visible light band to the near-infrared band can be manufactured.
[0130] Figure 13 is an illustrative plan view of a spectral filter 1000 that may be applied to the image sensor 10 in Figure 1.
[0131] Referring to Figure 13, the spectral filter 1000 may include a plurality of filter groups 1010 arranged in a two-dimensional configuration. Here, each filter group 1010 may include 16 unit filters F1 to F16 arranged in a 4x4 array.
[0132] The first unit filter F1 and the second unit filter F2 have central wavelengths UV1 and UV2 in the ultraviolet region, while the third unit filter F3, the fourth unit filter F4, and the fifth unit filter F5 may have central wavelengths B1 to B3 in the blue light region. The sixth unit filter F6 to the eleventh unit filter F11 have central wavelengths G1 to G6 in the green light region, while the twelfth unit filter F12, the thirteenth unit filter F13, and the fourteenth unit filter F14 may have central wavelengths R1 to R3 in the red light region. The fifteenth unit filter F15 and the sixteenth unit filter F16 may have central wavelengths NIR1 and NIR2 in the near-infrared region.
[0133] Figure 14 is another exemplary plan view of a spectral filter 1000 that may be applied to the image sensor 10 of Figure 1. For convenience, Figure 14 shows a plan view relating to one filter group 1020.
[0134] Referring to Figure 14, each filter group 1020 may include nine unit filters F1 to F9 arranged in a 3x3 array. Here, the first unit filter F1 and the second unit filter F2 may have central wavelengths UV1 and UV2 in the ultraviolet region, the fourth unit filter F4, the fifth unit filter F5, and the seventh unit filter F7 may have central wavelengths B1 to B3 in the blue light region, the third unit filter F3 and the sixth unit filter F6 may have central wavelengths G1 and G2 in the green light region, and the eighth unit filter F8 and the ninth unit filter F9 may have central wavelengths R1 and R2 in the red light region.
[0135] Figure 15 is another exemplary plan view of a spectral filter 1000 that may be applied to the image sensor 10 of Figure 1. For convenience, Figure 15 shows a plan view relating to one filter group 1030.
[0136] Referring to Figure 15, each filter group 1030 may include 25 unit filters F1 to F25 arranged in a 5x5 array. Here, the first unit filter F1, the second unit filter F2, and the third unit filter F3 may have central wavelengths UV1 to UV3 in the ultraviolet region, the sixth unit filter F6, the seventh unit filter F7, the eighth unit filter F8, the eleventh unit filter F11, and the twelfth unit filter F12 may have central wavelengths B1 to B5 in the blue light region, the fourth unit filter F4, the fifth unit filter F5, and the ninth unit filter F9 may have central wavelengths G1 to G3 in the green light region, and the tenth unit filter F10, the thirteenth unit filter F13, the fourteenth unit filter F14, the fifteenth unit filter F15, the eighteenth unit filter F18, and the nineteenth unit filter F19 may have central wavelengths R1 to R6 in the red light region. Furthermore, the 20th unit filter F20, the 23rd unit filter F23, the 24th unit filter F24, and the 25th unit filter F25 may have central wavelengths NIR1 to NIR4 in the near-infrared region.
[0137] The image sensor 10, including the aforementioned spectral filter, is also used in a variety of high-performance optical or high-performance electronic devices. Such electronic devices include, but are not limited to, smartphones, mobile phones, handphones, PDAs (personal digital assistants), laptops, PCs (personal computers), various portable devices, home appliances, security cameras, medical cameras, automobiles, Internet of Things (IoT) devices, and other mobile or non-mobile computing devices.
[0138] The electronic device may further include, in addition to the image sensor 10, a processor for controlling the image sensor, such as an application processor (AP). This processor can drive an operating system or application program, control numerous hardware or software components, and perform various data processing and calculations. The processor may further include a graphics processing unit (GPU) and / or an image signal processor. If the processor includes an image signal processor, the image (or video) acquired by the image sensor can be stored and / or output using the processor.
[0139] Figure 16 is a block diagram showing an example of an electronic device ED01 including an image sensor 10. Referring to Figure 16, in a network environment ED00, electronic device ED01 can communicate with other electronic devices ED02 via a first network ED98 (such as a short-range wireless communication network), or further communicate with other electronic devices ED04 and / or server ED08 via a second network ED99 (such as a long-range wireless communication network). Electronic device ED01 can communicate with electronic device ED04 via server ED08. Electronic device ED01 may also include a processor ED20, memory ED30, input device ED50, sound output device ED55, display device ED60, audio module ED70, sensor module ED76, interface ED77, haptic module ED79, camera module ED80, power management module ED88, battery ED89, communication module ED90, subscriber identification module ED96 and / or antenna module ED97. The electronic device ED01 may omit some of its components (such as the display device ED60) or add other components. Some of these components may also be implemented as a single integrated circuit. For example, the sensor module ED76 (fingerprint sensor, iris sensor, illuminance sensor, etc.) may also be implemented embedded in the display device ED60 (display, etc.). Furthermore, if the image sensor 10 includes a spectral function, some functions of the sensor module (color sensor, illuminance sensor) may be implemented as the image sensor 10 itself, rather than as a separate sensor module.
[0140] The processor ED20 can execute software (such as program ED40) and control one or more other components (hardware components, software components, etc.) of the electronic device ED01 connected to the processor ED20, and can perform various data processing or calculations. As part of such data processing or calculations, the processor ED20 can load instructions and / or data received from other components (such as sensor module ED76, communication module ED90) into volatile memory ED32, process the instructions and / or data stored in volatile memory ED32, and store the resulting data in non-volatile memory ED34. The processor ED20 may include a main processor ED21 (central processing unit, application processor, etc.) and an auxiliary processor ED23 (graphics processing unit, image signal processor, sensor hub processor, communication processor, etc.) which may be independent of or operate together with it. The auxiliary processor ED23 uses less power than the main processor ED21 and can perform specialized functions.
[0141] The auxiliary processor ED23 can act as a substitute for the main processor ED21 while the main processor ED21 is inactive (sleep), or, while the main processor ED21 is active (application execution), it can control the functions and / or states related to some components of the electronic device ED01 (such as the display device ED60, sensor module ED76, and communication module ED90) together with the main processor ED21. The auxiliary processor ED23 (such as the image signal processor and communication processor) can also be embodied as part of other functionally related components (such as the camera module ED80 and communication module ED90).
[0142] Memory ED30 can store various data required by the components of the electronic device ED01 (such as the processor ED20 and the sensor module ED76). This data may include, for example, software (such as the program ED40) and input and / or output data for the instructions associated with it. Memory ED30 may also include volatile memory ED32 and / or non-volatile memory ED34. Non-volatile memory ED32 may include an internal memory ED36 fixedly mounted within the electronic device ED01 and a removable external memory ED38.
[0143] Program ED40 is also stored as software in memory ED30 and may include an operating system ED42, middleware ED44 and / or application ED46.
[0144] The input device ED50 can receive instructions and / or data used by components of the electronic device ED01 (such as the processor ED20) from outside the electronic device ED01 (such as a user). The input device ED50 may include a microphone, mouse, keyboard, and / or digital pen (such as a stylus pen).
[0145] The audio output device ED55 can output an audio signal to the outside of the electronic device ED01. The audio output device ED55 may include a speaker and / or a receiver. The speaker is used for general purposes such as multimedia playback or recording and playback, and the receiver is also used to receive incoming telephone calls. The receiver may be coupled to part of the speaker or may be embodied as a separate, independent device.
[0146] The display device ED60 can visually provide information outside of the electronic device ED01. The display device ED60 may include a display, a hologram device or a projector, and a control circuit for controlling said device. The display device ED60 may also include touch circuitry configured to sense touches and / or sensor circuitry (such as a pressure sensor) configured to measure the intensity of the force produced by the touch.
[0147] The audio module ED70 can convert sound into electrical signals, or vice versa. The audio module ED70 can acquire sound via the input device ED50, or output sound via the speakers and / or headphones of other electronic devices (such as electronic device ED02) directly or wirelessly connected to the sound output device ED55 and / or electronic device ED01.
[0148] Sensor module ED76 can sense the operating state of electronic device ED01 (power, temperature, etc.) or external environmental conditions (user status, etc.), and generate electrical signals and / or data values corresponding to the sensed state. Sensor module ED76 may include gesture sensors, gyro sensors, barometric pressure sensors, magnetic sensors, acceleration sensors, grip sensors, proximity sensors, color sensors, IR (infrared) sensors, biosensors, temperature sensors, humidity sensors, and / or illuminance sensors.
[0149] Interface ED77 can support one or more specified protocols used to connect electronic device ED01 directly or wirelessly with other electronic devices (such as electronic device ED02). Interface ED77 may include HDMI (High Definition Multimedia Interface, registered trademark), USB (Universal Serial Bus) interface, SD (Secure Digital) card interface, and / or audio interface.
[0150] The coupling terminal ED78 may include a connector that allows electronic device ED01 to be physically connected to other electronic devices (such as electronic device ED02). The coupling terminal ED78 may also include an HDMI connector, a USB connector, an SD card connector, and / or an audio connector (such as a headphone connector).
[0151] The ED79 haptic module can convert electrical signals into mechanical stimuli (such as vibration or movement) or electrical stimuli that the user can perceive through touch or kinesthetic sense. The ED79 haptic module may include a motor, a piezoelectric element, and / or an electrical stimulator.
[0152] The camera module ED80 can capture still images and videos. The camera module ED80 may include a lens assembly containing one or more lenses, the image sensor 10 in Figure 1, an image signal processor, and / or a flash. The lens assembly included in the camera module ED80 can collect light emitted from the subject being imaged.
[0153] The power management module ED88 can manage the power supplied to the electronic device ED01. The power management module ED88 is also implemented as part of the PMIC (power management integrated circuit).
[0154] Battery ED89 can supply power to the components of the electronic device ED01. Battery ED89 may include a non-rechargeable primary battery, a rechargeable secondary battery, and / or a fuel cell.
[0155] The communication module ED90 can establish direct (wired) communication channels and / or wireless communication channels between electronic device ED01 and other electronic devices (electronic devices ED02, ED04, server ED08, etc.), and support communication through the established communication channels. The communication module ED90 may include one or more communication processors that operate independently of processor ED20 (application processor, etc.) and support direct and / or wireless communication. The communication module ED90 may also include wireless communication modules ED92 (cellular communication module, near-field wireless communication module, GNSS (global navigation satellite system)) and / or wired communication modules ED94 (LAN (local area network) communication module, power line communication module, etc.). Of these communication modules, the relevant communication module can communicate with other electronic devices via a first network ED98 (short-range communication networks such as Bluetooth®, Wi-Fi (wireless fidelity) direct, or IrDA (infrared data association)) or a second network ED99 (long-range communication networks such as cellular networks, the internet, or computer networks (LAN, WAN, etc.)). Such various types of communication modules may be integrated into a single component (such as a single chip) or embodied by multiple separate components (multiple chips). The wireless communication module ED92 can use subscriber information (such as the International Mobile Subscriber Identifier (IMSI)) stored in the subscriber identification module ED96 to verify and authenticate the electronic device ED01 within a communication network such as the first network ED98 and / or the second network ED99.
[0156] The antenna module ED97 can transmit and / or receive signals and / or power to or from an external source (such as other electronic devices). The antenna may include a radiator consisting of a conductive pattern formed on a substrate (such as a PCB (printed circuit board)). The antenna module ED97 may include one or more antennas. If multiple antennas are included, the communication module ED90 may select an antenna from among the multiple antennas that is suitable for the communication scheme used in the communication network, such as the first network ED98 and / or the second network ED99. Signals and / or power are transmitted and received between the communication module ED90 and other electronic devices via the selected antenna. In addition to the antenna, other components (such as an RFIC (radio frequency integrated circuit)) may also be included as part of the antenna module ED97.
[0157] Some of the components are interconnected with peripheral devices via communication methods (bus, GPIO (general purpose input and output), SPI (serial peripheral interface), MIPI (mobile industry processor interface), etc.), and can exchange signals (instructions, data, etc.) with each other.
[0158] Commands or data are transmitted and received between electronic device ED01 and external electronic device ED04 via server ED08 connected to the second network ED99. Other electronic devices ED02 and ED04 may be identical to electronic device ED01 or of a different type. All or part of the operations performed by electronic device ED01 may be performed by one or more of the other electronic devices ED02, ED04, and ED08. For example, when electronic device ED01 needs to perform a certain function or service, instead of performing the function or service autonomously, it can request one or more other electronic devices to perform part or all of that function or service. One or more other electronic devices that receive the request can perform the additional function or service related to the request and transmit the results of the execution to electronic device ED01. Cloud computing technology, distributed computing technology, and / or client-server computing technology may be used for this purpose.
[0159] Figure 17 is a block diagram illustrating the camera module ED80 of Figure 16. Referring to Figure 17, the camera module ED80 may include a lens assembly CM10, a flash CM20, an image sensor (e.g., image sensor 10 (Figure 1)), an image stabilizer CM40, a memory CM50 (such as buffer memory), and / or an image signal processor CM60. The lens assembly CM10 can collect light emitted from the subject being photographed. The camera module ED80 may include multiple lens assemblies CM10, in which case the camera module ED80 may also be a dual camera, a 360° camera, or a spherical camera. Some of the multiple lens assemblies CM10 may have the same lens attributes (angle of view, focal length, autofocus, F-number, optical zoom, etc.) or different lens attributes. The lens assembly CM10 may include a wide-angle lens or a telephoto lens.
[0160] The flash CM20 can emit light used to enhance light emitted or reflected from the subject. The flash CM20 may include one or more light-emitting diodes (such as RGB (red-green-blue) LEDs, white LEDs, infrared LEDs, ultraviolet LEDs, etc.) and / or a xenon lamp. The image sensor 10 is also the image sensor described in Figure 1, and can acquire an image corresponding to the subject by converting light emitted or reflected from the subject and transmitted through the lens assembly CM10 into an electrical signal. The image sensor 10 may include one or more sensors selected from image sensors with different attributes, such as an RGB sensor, a BW (black and white) sensor, an IR sensor, or a UV sensor. Each sensor included in the image sensor 10 is also embodied as a CCD sensor and / or a CMOS sensor.
[0161] The image stabilizer CM40 responds to the movement of the camera module ED80 or the electronic device CM01 containing it by moving one or more lenses or image sensors 10 included in the lens assembly CM10 in a specific direction, or by controlling the operating characteristics of the image sensors 10 (such as adjusting the read-out timing) to compensate for the negative effects of the movement. The image stabilizer CM40 can sense the movement of the camera module ED80 or the electronic device ED01 by utilizing a gyro sensor (not shown) or an accelerometer (not shown) located inside or outside the camera module ED80. The image stabilizer CM40 can also be implemented optically.
[0162] Memory CM50 can store some or all of the image data acquired via the image sensor 10 for subsequent image processing. For example, when multiple images are acquired at high speed, the acquired original data (Bayer-patterned data, high-resolution data, etc.) is stored in memory CM50 and used to display only the low-resolution images, after which the original data of the selected (user-selected, etc.) image is transmitted to the image signal processor CM60. Memory CM50 is integrated into the memory ED30 of the electronic device ED01, or it can be configured as a separate memory that operates independently.
[0163] The image signal processor CM60 can perform image processing on images acquired via the image sensor 10 or image data stored in memory CM50. Image processing may include depth map generation, three-dimensional modeling, panorama generation, feature point extraction, image synthesis, and / or image compensation (noise reduction, resolution adjustment, brightness adjustment, blurring, sharpening, softening, etc.). The image signal processor CM60 can control components included in the camera module ED80 (such as the image sensor 10) (such as exposure time control or readout timing control). Images processed by the image signal processor CM60 may be further stored in memory CM50 for additional processing, or provided to external components of the camera module ED80 (such as memory ED30, display device ED60, electronic device ED02, electronic device ED04, server ED08, etc.). The image signal processor CM60 may be integrated into processor ED20 or configured as a separate processor operating independently of processor ED20. If the image signal processor CM60 is configured as a separate processor from the processor ED20, the image processed by the image signal processor CM60 will undergo further image processing by the processor ED20 and then be displayed via the display device ED60.
[0164] The electronic device ED01 may include multiple camera modules ED80, each having different attributes or functions. In such a case, one of the camera modules ED80 may be a wide-angle camera and another a telephoto camera. Similarly, one of the camera modules ED80 may be a front camera and another a rear camera. An image sensor 10 according to one embodiment can be applied to a mobile phone or smartphone 1100 shown in Figure 18, a tablet or smart tablet 1200 shown in Figure 19, a digital camera or camcorder 1300 shown in Figure 20, a notebook computer 1400 shown in Figure 21, or a television or smart television 1500 shown in Figure 22, etc. For example, a smartphone 1100 or smart tablet 1200 may include multiple high-resolution cameras, each equipped with a high-resolution image sensor. These high-resolution cameras can be used to extract depth information of subjects in the image, adjust the outfocusing of the image, or automatically identify subjects in the image.
[0165] Furthermore, the image sensor 10 can be applied to the smart refrigerator 1600 shown in Figure 23, the security camera 1700 shown in Figure 24, the robot 1800 shown in Figure 25, and the medical camera 1900 shown in Figure 26. For example, the smart refrigerator 1600 can use the image sensor to automatically recognize food items inside the refrigerator and inform the user via smartphone about the presence of specific food items, the types of food items being added or removed, etc. The security camera 1700 can provide ultra-high-resolution images and, using high sensitivity, can recognize objects or people in the image even in dark environments. The robot 1800 can be deployed to disaster sites or industrial sites where people cannot directly approach and can provide high-resolution images. The medical camera 1900 can provide high-resolution images for diagnosis or surgery and can dynamically adjust its field of view.
[0166] Furthermore, the image sensor 10 can be applied to a vehicle 2000, as illustrated in Figure 27. The vehicle 2000 may include a plurality of vehicle cameras 2010, 2020, 2030, and 2040 arranged in various positions, and each of the vehicle cameras 2010, 2020, 2030, and 2040 may include an image sensor according to one embodiment. The vehicle 2000 can use the plurality of vehicle cameras 2010, 2020, 2030, and 2040 to provide the driver with a variety of information relating to the interior or surroundings of the vehicle 2000, and can automatically recognize objects or people in the image and provide information necessary for autonomous driving.
[0167] According to an exemplary embodiment, broadband characteristics can be achieved by including multiple band filters with different reflection wavelength bands while the spectral filter shares a cavity. According to other exemplary embodiments, an image sensor including the aforementioned spectral filter may be provided, and an electronic device including the image sensor may be provided.
[0168] Even if the image sensor and electronic device containing the aforementioned spectral filter are described with reference to one embodiment illustrated in the drawings, these are merely illustrative, and a person skilled in the art will understand that a variety of modifications and equivalent other embodiments are possible. Therefore, the disclosed embodiments should be considered in an explanatory rather than restrictive manner. The scope of rights is indicated in the claims, not in the foregoing description, and all differences within an equivalent scope should be interpreted as being included within the scope of rights. [Explanation of Symbols]
[0169] 10 Image Sensors 11. Spectroscopic filters 12 Sensing elements 100,100a Unit Filter 110 First Band Filter 120 Second Band Filter C Cavity DBR Bragg Reflector R resonance layer
Claims
1. In a spectral filter, The first resonant layer includes a cavity, A first Bragg reflector and a second Bragg reflector are arranged separately with the first resonant layer in between, A second resonant layer comprising at least a portion of the first Bragg reflective layer and the second Bragg reflective layer, and the cavity, It includes a third Bragg reflector and a fourth Bragg reflector, which are spaced apart with respect to the second resonant layer, A spectral filter in which the first Bragg reflective layer is in contact with the third Bragg reflective layer, and the second Bragg reflective layer is in contact with the fourth Bragg reflective layer.
2. Each of the first Bragg reflective layer to the fourth Bragg reflective layer is: The spectral filter according to claim 1, having a structure in which multiple material layers having different refractive indices are stacked on top of each other.
3. The spectral filter according to claim 1, wherein each of the first to fourth Bragg reflecting layers includes a dispersed Bragg reflector (DBR).
4. The first Bragg reflective layer and the second Bragg reflective layer are The spectral filter according to claim 1, which is symmetrical with respect to the first resonant layer.
5. The third Bragg reflective layer and the fourth Bragg reflective layer are The spectral filter according to claim 1, which is symmetrical with respect to the second resonant layer.
6. The thickness of the material layers included in the first Bragg reflective layer and the second Bragg reflective layer is The spectral filter according to claim 1, wherein the thickness of the material layers contained in the third Bragg reflective layer and the fourth Bragg reflective layer is different from that of the other.
7. The thickness of the material layers included in the first Bragg reflective layer and the second Bragg reflective layer is The spectral filter according to claim 1, wherein the thickness is thinner than the thickness of the material layers contained in the third Bragg reflective layer and the fourth Bragg reflective layer.
8. The aforementioned second resonant layer is The spectral filter according to claim 1, comprising the first Bragg reflective layer and the second Bragg reflective layer.
9. The spectral filter according to claim 8, wherein the first surface of the first Bragg reflective layer and the first surface of the second Bragg reflective layer are in contact with the first resonant layer.
10. The spectral filter according to claim 9, wherein the second surfaces of the first Bragg reflective layer and the second Bragg reflective layer, which face each of the first surfaces, are in contact with the third Bragg reflective layer and the fourth Bragg reflective layer, respectively.
11. The aforementioned second resonant layer is The spectral filter according to claim 1, comprising only one of the first Bragg reflective layer and the second Bragg reflective layer.
12. The spectral filter according to claim 11, wherein only one of the first Bragg reflective layer and the second Bragg reflective layer is in contact with the first resonant layer.
13. The spectral filter according to claim 11, wherein the remaining layer of the first Bragg reflective layer and the second Bragg reflective layer is spaced apart from the first resonant layer, with either the third Bragg reflective layer or the fourth Bragg reflective layer in between.
14. The spectral filter according to claim 1, wherein the wavelength of the wave transmitted through the spectral filter is determined by at least one of the effective refractive index of the cavity and the thickness of the cavity.
15. The aforementioned spectroscopic filter is The spectral filter according to claim 1, comprising a first unit filter through which light of a first wavelength is transmitted, and a second unit filter through which light of a second wavelength different from the first wavelength is transmitted.
16. The spectral filter according to claim 15, wherein the effective refractive index of the cavity included in the first unit filter and the effective refractive index of the cavity included in the second unit filter are different from each other.
17. The spectral filter according to claim 16, wherein the material pattern of the cavity contained in the first unit filter and the material pattern of the cavity contained in the second unit filter are different from each other.
18. A spectral filter according to any one of claims 1 to 17, An image sensor including a pixel array that receives light transmitted through the spectral filter.
19. An electronic device including an image sensor as described in claim 18.
20. The electronic device according to claim 19, wherein the electronic device includes a mobile phone, smartphone, tablet, smart tablet, digital camera, camcorder, notebook computer, television, smart television, smart refrigerator, security camera, robot, or medical camera.
Citation Information
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