TW202004168A - Optical sensor - Google Patents

Abstract

An optical sensor, adapted for sensing a measurable object, includes a sensing unit that reacts with the measurable object to generate a color change of the sensing unit, a first light-transmitting electrode unit located below the sensing unit, a light-receiving unit located below the first light-transmitting electrode unit, a second light-transmitting electrode unit located below the light-receiving unit and including a light-transmitting portion and a light-shielding portion, and a light-emitting unit located below the second light-transmitting electrode unit for emitting light toward the sensing unit.

Description

Optical sensor

The invention relates to a sensor, in particular to an optical sensor.

In the past, after the hazardous substance sensing film sensed the hazardous substance, the colorimetric method can be used to roughly confirm the concentration of the hazardous substance. However, this method has an inaccurate concentration of harmful substances, and even when the concentration of harmful substances is too low, it cannot be compared, so it is impossible to accurately confirm the existence of harmful substances. In addition, spectroscopic instruments can also be used to confirm the presence and concentration of hazardous substances. However, the spectroscopic instrument used in this method is a large-scale device and has a high cost. There is a problem that it is inconvenient to carry and the presence and concentration of harmful substances cannot be confirmed immediately.

Taiwan Patent Announcement No. 565941 discloses an optical measurement system for measuring the concentration of an object to be measured. The optical measurement system includes a concentration sensing device, a light source, and a light detector. The concentration sensing device includes a concentration detection film, an optical waveguide, and an optical waveguide. The light input waveguide and the light output waveguide are coupled to the concentration detection film. The light source is arranged at the light entrance end of the light entrance waveguide. The light detector is arranged at the light output end of the light output waveguide. After the concentration detection film reacts with the analyte, the light source emits a first light beam, and the first light beam is transmitted to the concentration sensing device through the light entrance end of the light entrance waveguide and is sensed by the concentration The device receives, and then, the concentration sensing device emits a second light beam, and the second light beam is transmitted to the light detector through the light output end of the light output waveguide and received by the light detector. The light intensity of the second light beam can be used to calculate the concentration of the analyte.

Although the optical measurement system of the patent case has the advantages of low cost and real-time measurement of the concentration of the analyte, the patent case needs to pass through the optical waveguide and the optical waveguide as the signal transmission medium, which is likely to cause optical signal transmission The problem of optical signal distortion in the process. In addition, the patent case uses optical fibers as the optical waveguide and the optical waveguide. When the optical fiber signal is connected to the photodetector and converted to an electrical signal, the optical coupling is often poor due to the inability to align the contacts and the good fixation. As well as the problem of large attenuation of the optical signal, when there is vibration in the environment, the slight displacement of the coupling point will cause noise or signal variation, which makes it difficult to interpret the sensed signal.

Therefore, the object of the present invention is to provide an optical sensor that is easy to carry, can avoid signal distortion, and can immediately confirm the presence of harmful substances.

Therefore, the optical sensor of the present invention is used for sensing the object to be tested, and includes a sensing unit for generating a color change with the object to be tested, and a first light transmission under the sensing unit An electrode unit, a light receiving unit located below the first light penetrating electrode unit, a second light transmitting electrode unit located below the light receiving unit and including a light penetrating portion and a light shielding portion, and a The two light penetrating the light emitting unit below the electrode unit and used to emit light toward the sensing unit.

The effect of the present invention is that: through the sensing unit, the first light penetrating electrode unit, the light receiving unit, the second light penetrating electrode unit, and the light emitting unit are stacked in a stacking direction, so that the light is emitted by the The light emitted by the unit can directly enter the sensing unit, and then the sensing unit can provide a reflected light, and the reflected light can directly enter the light receiving unit and be absorbed by the light receiving unit. A light penetrating electrode unit and the second light penetrating electrode unit can directly and immediately convert the light intensity of the reflected light into a current signal, and can directly reflect the presence of the object to be measured. Also. The concentration of the test object can also be reflected by the change in current signal caused by the change in light intensity.

Before the present invention is described in detail, it should be noted that in the following description, similar elements are denoted by the same number.

Referring to FIGS. 1 and 2, a first embodiment of the optical sensor of the present invention is used to sense the object to be measured, and includes a sensing unit 1, a first light penetrating electrode unit 2, and a light receiving unit 3. A second light penetrating electrode unit 4, a light emitting unit 5 for emitting light, and a light penetrating support substrate 6. The first light penetrating electrode unit 2 and the second light penetrating electrode unit 4 of the optical sensor are electrically connected to a current detector (not shown).

The test object is, for example but not limited to, a harmful substance. The harmful substance is, for example, but not limited to formaldehyde, urea, or mercury. The sensing unit 1 is adjusted or selected according to the object to be measured. The physical type of the sensing unit 1 can be solid state, gel state or solution state. The structure of the sensing unit 1 may be a film formed by the sensing element or a light-transmitting device containing the sensing element. The sensing element is, for example but not limited to, composed of 4-aminohydrazino-5-mercapto-1,2,4-triazole (4-amino hydrazino-5-mercapto-1,2,4-triazole, abbreviated AHMT), or a sensor composed of a component containing hydroxylamine sulfate and methyl yellow, or a sensor composed of rhodamine A sensing element formed by a component, or a sensing element formed by a component containing urease and phenol red. The rhodamine-like substance is, for example but not limited to, rhodamine or rhodamine hydrazone. In the first embodiment, the analyte is formaldehyde, and the sensing unit 1 includes a sensing solution formed by a component containing bis(hydroxylamine sulfate) and methyl yellow, and a container containing the sensing The light of the solution penetrates the container (not shown), or the analyte is urea, and the sensing unit 1 includes a sensing solution formed by a component containing urease and phenol red and a container containing the The light of the sensing solution penetrates the container (not shown). The volume of these sensing solutions is 3 ml.

The first light-transmitting electrode unit 2 is located below the sensing unit 1 and contacts the sensing unit 1 or is adjacent to the sensing unit 1. When the first light penetrating electrode unit 2 is adjacent to the sensing unit 1, the distance between the first light penetrating electrode unit 2 and the sensing unit 1 is, for example, 0.1 cm to 0.5 cm. The thickness of the first light penetrating electrode unit 2 ranges from 5 nm to 999 nm. The first light transmission electrode unit 2 includes a light transmission electrode layer 21. The material of the light transmission electrode layer 21 is, for example but not limited to, indium tin oxide or metal. The material of the transparent supporting substrate is, for example, but not limited to glass or plastic. In the first embodiment, the thickness of the first light transmission electrode unit 2 is 300 nm, and the light transmission electrode layer 21 is an indium tin oxide layer.

The light receiving unit 3 is located below the first light transmitting electrode unit 2 and is connected to the light transmitting electrode layer 21 of the first light transmitting electrode unit 2. The thickness of the light receiving unit 3 ranges from 20 nm to 2,000 nm. The light receiving unit 3 includes a light receiving layer 31. The material of the light receiving layer 31 is, for example but not limited to, an organic material capable of generating electron hole pairs after light absorption or a material doped with n-type or p-type substances. The organic material is for example but not limited to 9,9-dioctylfluorene-N-(4-butylphenyl)diphenylamine copolymer {poly[9,9-dioctylfluorene-co-N-(4-butylphenyl)diphenylamine] , Referred to as TFB}, phenyl-C61-butyric acid methyl ester (PC61BM), poly{4,8-bis(5-(2-ethylhexyl)thiophene-2- Group) benzo[1,2-b;4,5-b']dithiophene-2,6-diyl-4-(2-ethylhexyloxycarbonyl)-3-fluoro-thieno[3 ,4-b]thiophene-2,6-diyl)}{poly[4,8-bis(5-(2-ethylhexyl)thiophene-2-yl)-benzo[1,2-b;4,5- b']dithiophene-2,6-diyl-4-(2-ethylhexyloxycarbonyl)-3-fluoro-thieno[3,4-b]-thiophene))-2,6-diyl], referred to as PBDTTT-EFT}, poly (3-Hexylthiophene) [poly(3-hexylthiophene), referred to as P3HT], poly{4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2- b;4,5-b']dithiophene-2,6-diyl-4-(2-ethylhexyl)-thieno[3,4-b]thiophene-2,6-diyl}( {poly[4,8-bis(5-(2-ethylhexyl)thiophene-2-yl)-benzo[1,2-b;4,5-b']dithiophene-2,6-diyl-4-(2 -ethylhexanoyl)-thieno[3,4-b]-thiophene)-2,6-diyl]}, referred to as PBDTTT-CT), or phenyl-C71-butyric acid methyl ester , Referred to as PC71BM) and so on. In the first embodiment, the thickness of the light receiving unit 3 is 400 nm, and the light receiving layer 31 is a light receiving layer including PBDTTT-CT and PC71BM. The weight ratio of the PBDTTT-CT and PC71BM is 1:1.5.

The second light penetrating electrode unit 4 is located below the light receiving unit 3 and is connected to the light receiving unit 3. The thickness of the second light penetrating electrode unit 4 ranges from 10 nm to 900 nm. The second light transmission electrode unit 4 includes an electrode layer 43. The material of the electrode layer 43 is, for example but not limited to aluminum. The structural type of the electrode layer 43 is an interdigitated type, and the electrode layer 43 includes a light-shielding body 431 as a light-shielding portion 42 and a plurality of light-transmitting portions 41 cooperating together and penetrating the light-shielding body 431 for The light of the light emitting unit 5 passes through and reaches the through hole 430 of the sensing unit 1. The through holes 430 are rectangular. The size of the through holes 430 ranges from 200 nm to 5 mm. In the first embodiment, the thickness of the second light transmitting electrode unit 4 is 100 nm, the electrode layer 43 is an aluminum layer, and the size of the through holes 430 is 110 μm. It is worth noting that, when the structure of the electrode layer 43 is a finger type, the light part of the light emitting unit 5 will be blocked by the light shielding body 431 of the electrode layer 43 to avoid absorption by the light receiving unit 3, Then the background current value can be reduced (as described later). In addition, the structural type of the electrode layer 43 is not limited to the interdigitated type, as long as the light-shielding body 431 of the electrode layer 43 can achieve any light-shielding structure, and the shape of the through holes 430 is not limited to rectangular. Any shape that can pass the light of the light-emitting unit 5 can be used.

The light transmission supporting substrate 6 is located below the second light transmission electrode unit 4 and is connected to the electrode layer 43 of the second light transmission electrode unit 4. The material of the light transmission support substrate 6 is, for example, but not limited to glass or plastic. The thickness of the light penetrating support substrate 6 ranges from 200 μm to 2 mm. It is worth noting that the light penetrating support substrate 6 is used to support any or all of the elements above it. Therefore, the arrangement and position of the light penetrating support substrate 6 are based on the above The mechanical strength (such as hardness) of each element is set and the position is adjusted. In addition, when the mechanical strength of the elements above it is sufficient, it is not necessary to provide the light penetrating support substrate 6. In the first embodiment, the light transmission support substrate 6 is a glass substrate, and the thickness of the light transmission support substrate 6 is 700 μm.

The light emitting unit 5 is located below the light penetrating support substrate 6. The light emitted by the light-emitting unit 5 is selected according to the color produced by the sensing unit 1 and the object to be tested, that is, corresponding to the light band in which the absorption spectrum changes after the sensing unit 1 interacts with the object to be tested. The light-emitting unit 5 is, for example but not limited to, a light-emitting diode lamp or a laser lamp. In the first embodiment, when the test object is urea, the light-emitting unit 5 is a green light-emitting diode lamp that emits light with a main wavelength of 518 nm and an illuminance of 18300 lux, or, when the test object is formaldehyde The light-emitting unit 5 emits green laser light with a main wavelength of 532 nm and an illuminance of 65 W/m ² .

When operating the optical sensor of the present invention, first, the first light penetrating electrode unit 2 and the second light penetrating electrode unit 4 are electrically connected to an electrical device, and the electrical device includes a voltage supply and a current detection Device. The voltage supplier is provided with a constant bias voltage, and the light emitting unit 5 emits light. The light passes through the light penetrating portion 41 of the second light penetrating electrode unit 4 and passes through the light receiving unit 3 and the first light penetrating electrode unit 2 to reach the sensing unit 1. Then, the sensing unit 1 will provide a first reflected light and be absorbed by the light receiving unit 3. After the light receiving unit 3 absorbs the first reflected light, the light signal of the first reflected light is converted into a current signal by the first light penetrating electrode unit 2 and the second light penetrating electrode unit 4, And with the current detector, a background current value is obtained. Then, the object to be tested is brought into contact with the sensing unit 1 to produce a color change of the sensing unit 1, at this time, the light emitted by the light-emitting unit 5 will penetrate the electrode unit via the second light The light transmitting portion 41 of 4 passes through the light receiving unit 3 and the first light transmitting electrode unit 2 to reach the sensing unit 1. The sensing unit 1 will provide a second reflected light different from the first reflected light due to the color change, and the second reflected light will be passed by the light receiving unit 3 through the second light penetrating electrode unit 4 absorb. After the light receiving unit 3 absorbs the second reflected light, the light signal of the second reflected light is converted into a current signal by the first light penetrating electrode unit 2 and the second light penetrating electrode unit 4 , And then use the current detector to obtain a detection current value. By comparing the background current value and the detected current value, a current difference or current rate of change is obtained, and through the current difference or current rate of change, it can be known whether there is the object to be measured. In addition, by establishing a database of the concentration value of the test object with a known concentration and its detection current value, its current difference or its current change rate, the concentration value of the test object of unknown concentration can be further obtained.

Referring to FIG. 3, a second embodiment of the optical sensor of the present invention differs from the first embodiment in that the light penetrates the support substrate 6. In the second embodiment, the light transmission support substrate 6 is located between the sensing unit 1 and the first light transmission electrode unit 2 and connects and supports the light transmission of the first light transmission electrode unit 2 Electrode layer 21.

In the present invention, several sensing data are provided and are performed using the optical sensor of the second embodiment, refer to Table 1 to Table 4.

Table 1

Table 2

table 3

Table 4

Referring to FIGS. 4 and 5, a third embodiment of the optical sensor of the present invention differs from the first embodiment in that the first light penetrating electrode unit 2 and the light receiving unit 3. In the third embodiment, the first light-transmitting electrode unit 2 includes a light-transmitting electrode layer 22 and a plurality of through holes 20 penetrating the light-transmitting electrode layer 22 and allowing light of the light-emitting unit 5 to pass through. The structural type of the first light-transmitting electrode unit 2 is an interdigitated type, and the light-shielding body 431 of the light-transmitting electrode layer 22 and the electrode layer 43 of the second light-transmitting electrode unit 4 are spatially overlapping (See Figure 5). The size of the perforations 20 ranges from 200 nm to 5 mm. The light-receiving unit 3 includes a light-receiving layer 32 formed with a plurality of through holes 30 penetrating and passing light of the light-emitting unit 5. The size of the through holes 30 ranges from 200 nm to 5 mm. The through holes 20 of the light penetrating electrode layer 22 of the first light penetrating electrode unit 2, the through holes 30 of the light receiving layer 32 of the light receiving unit 3, and the electrodes of the second penetrating electrode unit 4 The through holes 430 of the layer 43 are respectively spatially connected and overlapped, so that the light emitted by the light emitting unit 5 can pass through the through holes 430, the through holes 30, and the through holes 20 in order to reach The sensing unit 1.

It is worth noting that the through holes 30 of the light receiving unit 3 of the optical sensor of the third embodiment can directly pass the light from the light emitting unit 5 and reduce contact with the light receiving unit 3 to be absorbed , In turn, can reduce the background current value, however, in the optical sensor of the first embodiment and the optical sensor of the second embodiment, the light from the light-emitting unit 5 will contact the light-receiving unit 3 and Is absorbed, resulting in a larger background current quality. Therefore, compared to the optical sensor of the first embodiment and the optical sensor of the second embodiment, the optical sensor of the third embodiment is sensing More accurate.

Referring to FIG. 6, a fourth embodiment of the optical sensor of the present invention is used to sense the object to be measured, and includes a sensing unit 1, a first light penetrating electrode unit 2, a light receiving unit 3, a The second light penetrating electrode unit 4, a light emitting unit 5 for emitting light, and a light penetrating support substrate 6.

The object under test, the sensing unit 1, the first light penetrating electrode unit 2, and the light receiving unit 3 and the object under test, the sensing unit 1, the first light passing through of the first embodiment The transmissive electrode unit 2 is the same as the light receiving unit 3, so it will not be repeated here.

The second light penetrating electrode unit 4 is located below the light receiving unit 3 and is connected to the light receiving unit 3. The second light transmission electrode unit 4 includes a light shielding layer 44 and a light transmission electrode layer 46. The light-shielding layer 44 is located below the light-receiving unit 3 and is embedded in the light-receiving unit 3, and includes a light-shielding body 441 as a light-shielding portion 42, and a plurality of light-transmitting portions 41 cooperating together and penetrating the light-shielding The body 441 allows the light of the light emitting unit 5 to pass through to reach the through hole 440 of the sensing unit 1. The size of the through holes 440 ranges from 50 nm to 5 mm. The light penetrating electrode layer 46 is located below the light shielding layer 44 and is connected to the light shielding layer 44. The thickness of the light transmission electrode layer 46 ranges from 10 nm to 900 nm. The light transmission support substrate 6 is located below the second light transmission electrode unit 4 and is connected to the light transmission electrode layer 46 of the second light transmission electrode unit 4. The light emitting unit 5 is located below the light penetrating support substrate 6.

It is worth noting that the second light penetrating electrode unit 4 of the optical sensor of the first embodiment and the second embodiment is not easy to manufacture and has the problems of high cost and low yield, but the fourth The second light penetrating electrode unit 4 of the optical sensor of the embodiment is easy to manufacture, and thus can reduce cost and improve yield. Therefore, compared to the optical sensors of the first embodiment and the second embodiment, the optical sensor of the fourth embodiment has the advantages of low cost and high yield.

Referring to FIG. 7, a fifth embodiment of the optical sensor of the present invention differs from the fourth embodiment in that the second light penetrating electrode unit 4. In the fifth embodiment, the light penetrating electrode layer 46 of the second light penetrating electrode unit 4 is located between the light receiving unit 3 and the light penetrating support substrate 6 and is connected to the light receiving unit 3 and the light Pierce the support substrate 6. The light shielding layer 44 of the second light penetrating electrode unit 4 is located between the light penetrating support substrate 6 and the light emitting unit 5 and is connected to the light penetrating support substrate 6.

Referring to FIG. 8, a sixth embodiment of the optical sensor of the present invention differs from the fourth embodiment in that the second light penetrating electrode unit 4. In the sixth embodiment, the light transmission electrode layer 46 of the second light transmission electrode unit 4 is connected to the light receiving unit 3. The light-shielding layer 44 of the second light-transmitting electrode unit 4 is located between the light-transmitting electrode layer 46 and the light-transmitting support substrate 6, and is connected to the light-transmitting electrode layer 46 and the light-transmitting support substrate 6.

In summary, through the sensing unit 1, the first light penetrating electrode unit 2, the light receiving unit 3, the second light penetrating electrode unit 4, and the light emitting unit 5 are stacked in a stacking direction, The light emitted by the light-emitting unit 5 can directly enter the sensing unit 1, and then the sensing unit 1 can provide a reflected light, and the reflected light can directly enter the light receiving unit 3 and be received by the light receiving unit 3 Absorption, at this time, by the first light penetrating electrode unit 2 and the second light penetrating electrode unit 4, the light intensity of the reflected light can be directly and immediately converted into a current signal, which can directly reflect whether there is a pending Test object. Also. The current signal change caused by the change in light intensity can also reflect the concentration of the object to be measured, so it can indeed achieve the purpose of the invention.

However, the above are only examples of the present invention, and the scope of implementation of the present invention cannot be limited by this, any simple equivalent changes and modifications made according to the scope of the patent application of the present invention and the content of the patent specification are still classified as Within the scope of the invention patent.

1‧‧‧ Sensing unit 2‧‧‧ First light transmission electrode unit 21‧‧‧ Light transmission electrode layer 22‧‧‧ Light transmission electrode layer 20‧‧‧Perforation 3‧‧‧ Light receiving unit 31‧ ‧‧Light-receiving layer 32‧‧‧‧Light-receiving layer 30‧‧‧Through hole 4‧‧‧Second light penetrating electrode unit 41‧‧‧‧Light penetrating part 42‧‧‧Light blocking part 43‧‧‧Electrode layer 431 ‧‧‧Shading body 430‧‧‧Through hole 44‧‧‧Shading layer 441‧‧‧Shading body 440‧‧‧Through hole 46‧‧‧Light penetrating electrode layer 5‧‧‧Light emitting unit 6‧‧‧Light penetration Through support substrate

Other features and functions of the present invention will be clearly presented in the embodiments with reference to the drawings, in which: 　 FIG. 1 is a schematic cross-sectional view of a first embodiment of the optical sensor of the present invention; 　 FIG. 2 is the first A schematic exploded view of the embodiment; 　 FIG. 3 is a schematic cross-sectional view of a second embodiment of the optical sensor of the present invention; 　 FIG. 4 is a schematic cross-sectional view of a third embodiment of the optical sensor of the present invention; 　5 is a schematic perspective exploded view of the third embodiment; 　 FIG. 6 is a schematic cross-sectional view of a fourth embodiment of the optical sensor of the present invention; 　 FIG. 7 is a fifth embodiment of the optical sensor of the present invention A schematic cross-sectional view; and FIG. 8 is a schematic cross-sectional view of a sixth embodiment of the optical sensor of the present invention.

1‧‧‧sensing unit

2‧‧‧First light penetrating electrode unit

43‧‧‧electrode layer

430‧‧‧through hole

21‧‧‧Light penetrating electrode layer

3‧‧‧Light receiving unit

4‧‧‧Second light penetrating electrode unit

5‧‧‧Lighting unit

6‧‧‧light penetration support substrate

Claims (9)

An optical sensor for sensing an object to be tested includes: a sensing unit for interacting with the object to produce a color change; a first light penetrating electrode unit located below the sensing unit A light-receiving unit located below the first light-transmitting electrode unit; a second light-transmitting electrode unit located below the light-receiving unit and including a light-transmitting portion and a light-shielding portion; and a light-emitting unit located at The second light penetrates under the electrode unit and is used to emit light toward the sensing unit. The optical sensor according to claim 1, wherein the second light-transmitting electrode unit includes an electrode layer including a light-shielding body as the light-shielding portion, and a plurality of light-transmitting portions and The light passing through the light-shielding body passes through the light-emitting unit to reach the through hole of the sensing unit. The optical sensor according to claim 2, further comprising a light penetrating support substrate between the second light penetrating electrode unit and the light emitting unit. The optical sensor according to claim 2, further comprising a light transmissive support substrate between the sensing unit and the first light transmissive electrode unit. The optical sensor according to claim 2, wherein the first light penetrating electrode unit includes a light penetrating electrode layer, and a plurality of perforations penetrating the light penetrating electrode layer and allowing light of the light emitting unit to pass through The light-receiving unit includes a light-receiving layer formed with a plurality of through holes penetrating and passing through the light-emitting unit; the perforations of the light penetrating electrode layer of the first light penetrating electrode unit, the light receiving The through holes of the light receiving layer of the cell and the through holes of the electrode layer of the second penetrating electrode unit are respectively spatially connected and overlapped. The optical sensor according to claim 5, wherein the light-shielding bodies of the light transmission electrode layer and the electrode layer of the second light transmission electrode unit are spatially overlapped. The optical sensor according to claim 1, wherein the second light-transmitting electrode unit includes a light-shielding layer and a light-transmitting electrode layer, the light-shielding layer includes a light-shielding body as the light-shielding portion, and a plurality of Commonly used as the light penetrating part and penetrating the light-shielding body and allowing the light of the light emitting unit to pass through to reach the through hole of the sensing unit. The optical sensor according to claim 7, wherein the light-shielding layer is located between the light-receiving unit and the light-transmitting electrode layer, and the light-transmitting electrode layer is located between the light-shielding layer and the light-emitting unit. The optical sensor according to claim 7, wherein the light-shielding layer is located between the light-emitting unit and the light-transmitting electrode layer, and the light-transmitting electrode layer is located between the light-shielding layer and the light-receiving unit.

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