JP2020060509A - Optical measurement device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To transmit light from a plurality of light sources having different amounts of light to a measuring unit with an appropriate amount of light by using a low-cost space-saving reflection unit. SOLUTION: A measuring unit that measures a measurement target by light from a plurality of light sources, and a reflective housing in which light is incident from the plurality of light sources and diffusely reflected by an internal reflecting surface is emitted to the measuring unit. The reflection housing is provided at different positions for each of a plurality of light sources, and has a plurality of incident ports for light to be incident from each of the light sources and diffused reflection of the incident light. It also has a reflecting surface that absorbs a part of it, and an exit port that emits diffusely reflected light from the inside to the measurement unit, and the light emitted from each of the plurality of light sources is emitted from the emission port to the measurement unit. Based on the average reduction rate, which represents the rate at which the light emission amount of the light source decreases by the time it reaches the measurement unit, and the light emission amount of the light source, in order to set the emitted light amount to a value in a certain range, of a plurality of incident ports. Each is placed at a different position with respect to the position of the exit port. [Selection diagram] FIG. 4

Description

  The present invention relates to an optical measuring device equipped with a means for indirectly allowing light from a light source to reach a measuring section.

  In the conventional optical measuring device, when using a plurality of types of test paper or a plurality of types of light sources corresponding to the measurement items, a plurality of optical fibers provided for each light source allows the light from each light source to be in one place. In some cases, a method of collecting and irradiating the measurement part is adopted.

  Patent Document 1 below discloses a technique of reflecting light and irradiating a sample.

  In addition, Patent Document 2 below discloses a technique of measuring a reference light amount and a sample light amount using an integrating sphere.

JP, 03-194447, A Japanese Examined Patent Publication No. 61-028292

  When irradiating light from multiple light sources to the measurement part using optical fibers, the minimum bending radius is specified by the material of the optical fibers, so there was a limit to the miniaturization of the device to secure the space. . Moreover, the cost of the optical fiber is high, and the manufacturing cost due to the optical fiber used increases as the number of types of light sources increases. Therefore, the optical transmission system using the optical fiber is not suitable for a small and inexpensive device.

  On the other hand, when irradiating the light from the light source to the measurement section using a less expensive reflection unit without using an optical fiber, the light from each light source with different light intensity is transmitted to the measurement section at an appropriate light quantity. There was a problem that it was difficult to do. That is, in the case of an inexpensive light source, the light amount may vary depending on the light source used. If the light from each of such light sources is indirectly reflected from the light source including the reflection unit (the reflection housing and the connection portion connecting the reflection housing and the light source or the measurement unit) to the measurement unit, If the average reduction rate of light (the rate at which light decreases until it reaches the measurement unit) in the housing for reaching the same is the same, a light source with a small amount of light is used to detect the measurement target. In some cases, a sufficient amount of light cannot be obtained and the measurement target cannot be measured. On the other hand, in the case of a light source with a large amount of light, light saturation may occur beyond the upper limit of the amount of light that can be measured by the measuring unit (for example, the light receiving sensor). As described above, the light amount may be too large or too small depending on the relationship between the light amount of the light source, the sensitivity of the measuring unit, and the average reduction rate, which is a factor in designing a small and inexpensive optical measuring device. Had brought difficulties.

  Therefore, the embodiment of the present invention, in an optical measuring device using a reflection unit that transmits light from a plurality of light sources with different amounts of light to the measurement unit, low cost, space-saving, appropriate light from each light source. It is an object to transmit the amount of light to the measurement unit.

In a first aspect of the present disclosure, a plurality of light sources having different light emission amounts of at least one,
A measuring unit that measures a measurement target with light emitted from the plurality of light sources,
An optical measurement device comprising: a reflection housing into which the light emitted from the plurality of light sources is incident and the light diffusely reflected by an internal reflection surface is emitted to the measurement unit;
The reflective housing is
A plurality of entrances that are in communication with each of the plurality of light sources, are provided at different positions for each of the plurality of light sources, and light is incident to the inside from each of the plurality of light sources,
Diffuse reflection of the light incident from the plurality of entrances, and a reflecting surface that absorbs a part of the light when the diffuse reflection is performed,
An emission port that communicates with the measurement unit and that emits the light diffusely reflected by the reflection surface from the inside to the measurement unit,
For each of the plurality of light sources, in order to set the emitted light amount, which is the light amount when the light emitted from each of the plurality of light sources reaches the measurement unit through the emission port, to a value within a certain range, Based on the average reduction rate that represents the rate of decrease of the amount of light emission until reaching the measurement unit, and the amount of light emission of each of the plurality of light sources, each of the plurality of entrance ports with respect to the position of the exit port. Are placed in different positions,
The measurement unit optically measures the measurement target by irradiating the measurement target with the emitted light amount.

  In a second aspect of the present disclosure, in the first aspect, the light amount of each of the light sources is adjustable so that the emitted light amount corresponding to each of the light sources falls within a range narrower than the predetermined range. An adjusting unit is provided.

  According to a third aspect of the present disclosure, in the first or second aspect, the plurality of light sources emit light having different wavelengths.

  In a fourth aspect of the present disclosure, in the third aspect, at least two of the plurality of light sources emit light having wavelengths having sensitivity characteristics for different measurement targets.

  In a fifth aspect of the present disclosure, in any one of the first to fourth aspects, as for each of the plurality of entrance ports and the exit port, the light from the light source with the larger light emission amount has the above-mentioned average reduction rate. It is provided in a position that makes it larger.

  In a sixth aspect of the present disclosure, in the fifth aspect, each of the plurality of entrance ports and the exit port is diffused and reflected by the reflective surface by the measurement unit as light from a light source with a larger light emission amount. It is provided at a position where there are many.

  In a seventh aspect of the present disclosure, in any one of the first to sixth aspects, a gain adjusting unit that adjusts a light amount of light received by the measuring unit is provided, and the certain range is the gain adjusting unit. Is a range of light amount in which each of the emitted light amounts can be adjusted to a substantially constant value.

  In an eighth aspect of the present disclosure, in any one of the first to seventh aspects, a portion interposed between the measurement unit and the emission port, the reduction rate of the light amount is lower than that of the reflection surface. It has a measuring connection with a large surface.

  In a ninth aspect of the present disclosure, in any one of the first to eighth aspects, a portion interposed between each of the plurality of light sources and each of the plurality of entrances, the reflecting surface It has a surface with a greater rate of light reduction.

  In a tenth aspect of the present disclosure, in any one of the first to ninth aspects, the reflection housing has a perforated surface on which the plurality of entrance ports and the exit port are provided, and the perforated surface. It has a box shape having an opposed surface facing the surface and a connection surface connecting the perforated surface and the opposed surface.

  In an eleventh aspect of the present disclosure, in the tenth aspect, in the facing surface, a portion where the optical axis of the light source with the smallest light emission amount of the plurality of light sources in the reflection housing first comes into contact with the light is emitted. Inclined towards the mouth.

  In a twelfth aspect of the present disclosure, in the tenth or eleventh aspect, in the facing surface, a portion of the plurality of light sources in the reflection housing that comes in contact first with the optical axis of the light source with the largest light emission amount is It is perpendicular to the optical axis.

  In a thirteenth aspect of the present disclosure, in the twelfth aspect, the distance between the entrance corresponding to the light source with the largest light emission amount and the portion where its optical axis first abuts on the facing surface is different from the light source. The distance between the entrance corresponding to another light source and the optical axis of the entrance is first shorter than the distance on the facing surface.

  In a fourteenth aspect of the present disclosure, in the tenth to thirteenth aspects, a portion of the facing surface facing the emission port is parallel to the perforated surface.

  In a fifteenth aspect of the present disclosure, in the first to fourteenth aspects, the reflection of light on the reflection surface of the reflection housing has a color, shape, or material in which diffuse reflection is superior to specular reflection, or these. It is formed by any two or all of them.

  In the embodiment of the present invention, in the optical measurement, by reflecting the light from the light source in the reflective housing and irradiating the measurement target, a member such as an optical fiber that guides the light to the measurement target is not required, which reduces the manufacturing cost. The cost can be reduced and the device can be downsized.

  Further, when an optical fiber is used, an optical fiber is required for each light source, and thus the manufacturing cost due to the optical fiber used increases as the number of types of light sources increases. However, in the present embodiment, since only one reflective casing that can handle a plurality of light sources is an optical transmission system, it is possible to suppress an increase in the cost of the optical transmission system due to the increase in the types of light sources.

  In other words, in an optical measuring device using a reflection unit that transmits light from a plurality of light sources with varying amounts of light to the measurement unit, while appropriately reducing the manufacturing cost and downsizing the device, the light from each light source can be appropriately used. The amount of light can be transmitted to the measurement unit.

The principal part of the optical measuring device is shown in a side partial sectional view. The principal part of an optical measuring device is shown in a bottom perspective view. FIG. 3 is a bottom perspective view showing a state in which a part of the reflection housing is removed in the main part of the optical measurement device. The arrangement of the light source and the measurement unit is schematically shown. 7 schematically shows the transmission of light inside the reflective housing. The distance between the entrance and the facing surface is schematically shown. It is a functional block diagram of an optical measuring device. The block diagram shows the hardware configuration of the control unit.

<First mode>
The optical measurement device according to the first aspect of the present disclosure includes a plurality of light sources having different amounts of emitted light,
A measuring unit that measures a measurement target with light emitted from the plurality of light sources,
An optical measurement device comprising: a reflection housing into which light emitted from the plurality of light sources is incident and light diffusely reflected by an internal reflection surface is emitted to the measurement unit;
The reflective housing is
A plurality of entrances that are in communication with each of the plurality of light sources, are provided at different positions for each of the plurality of light sources, and light is incident to the inside from each of the plurality of light sources,
Diffuse reflection of the light incident from the plurality of entrances, and a reflecting surface that absorbs a part of the light when the diffuse reflection is performed,
An emission port that communicates with the measurement unit and that emits the light diffusely reflected by the reflection surface from the inside to the measurement unit,
For each of the plurality of light sources, in order to set the emitted light amount, which is the light amount when the light emitted from each of the plurality of light sources reaches the measurement unit through the emission port, to a value within a certain range, Based on the average reduction rate that represents the rate of decrease of the amount of light emission until reaching the measurement unit, and the amount of light emission of each of the plurality of light sources, each of the plurality of entrance ports with respect to the position of the exit port. Are placed in different positions,
The measurement unit optically measures the measurement target by irradiating the measurement target with the emitted light amount.

  In the optical measuring device of this aspect, a plurality of light sources are provided. The type of light source is not particularly limited, but for example, an LED or the like can be used. The plurality of light sources may include the same light amount, but at least one light source has a different light amount from other light sources. Further, although the respective light sources emit light at different timings, a plurality of light sources can be simultaneously emitted for the purpose of increasing the light amount, such as when using a light source with a small light amount.

  The measurement target of this aspect refers to an object that is actually irradiated with light to perform measurement, and includes a test tool capable of dipping or containing a sample (for example, a liquid such as blood).

  The measurement unit receives light emitted from a plurality of light sources. The light received by the measurement unit is emitted from the light source, but the light from the light source is a reflection housing, a light source connection unit that connects the reflection housing and the light source, and a measurement connection unit that connects the reflection housing and the measurement unit. By repeatedly diffusing and reflecting on the surface such as, etc., it finally reaches the measurement unit. During this diffuse reflection, part of the light is absorbed by the substance that reflects the light. By the time it reaches the measurement unit, light is absorbed during diffuse reflection on the reflective surface, and among the light emitted from the light source, it may be reflected without reaching the measurement unit depending on the light path. By repeating the diffuse reflection and the absorption that occurs at that time in the unit, there is a certain amount of light that completely decreases before reaching the measurement unit, so the light with the reduced light amount is applied to the measurement target. Becomes Finally, of the light that irradiates the measurement target with the light of which the light amount is reduced, the light that is transmitted or reflected reaches the measurement unit. Therefore, naturally, the measuring unit does not receive all the light emitted from the light source.

  Diffuse reflection in this aspect refers to reflection in which incident light is reflected at various angles, and is sometimes called diffuse reflection. Further, at the time of reflection, part of the light may be specularly reflected at the same time as the diffuse reflection. In general, the higher the reflectance of the substance, the more the specular reflection becomes superior to the diffuse reflection. On the contrary, the substance that positively performs diffuse reflection has the advantage that diffuse reflection is superior to specular reflection.

  Light absorption means that a substance absorbs a part of the energy of light when the substance is irradiated with light, and the atoms and molecules that compose the substance when the substance is irradiated with light are in the ground state. Absorption of light occurs as a result of being excited from the to the excited state. As a result of the absorption of light, the amount of absorbed light decreases. In general, a substance that absorbs more light has a color closer to black.

  The measurement unit is not particularly limited as long as it can convert the received light amount into some kind of quantitative signal such as an electric signal. For example, a photodiode can be used as this measuring unit. Further, the measurement unit may have different sensitivities depending on wavelengths, and in this aspect, the positions of the entrance and the exit can be set based on the sensitivity of the measurement unit.

  The reflection housing is a member that receives light from a plurality of light sources, reflects the light inside, and emits the light to the measurement unit. The reflection housing is provided with entrances, which are holes through which the light from the light source enters, at different positions corresponding to the plurality of light sources. In addition, an emission port that is a hole for emitting light to the measurement unit is also provided. Further, the inner surface of the reflective housing is a reflecting surface that diffuses and reflects the light incident from the entrance to the exit.

  In this aspect, each light source is provided with an entrance port connected to a different light source. However, the light entering the inside of the reflective casing from each entrance port is diffused and reflected by the reflecting surface, and then exits to the exit port. The reached portion is emitted to the measurement unit through the emission port connected to the measurement unit. During this period, the amount of light emitted from the light source decreases due to the absorption of light during diffuse reflection on the reflecting surface and the presence of light that has completely decreased before reaching the measurement unit. The amount of light that is emitted from and reaches the measurement unit is the amount of emitted light that is the amount of light resulting from the reduction. The rate at which the amount of emitted light decreases to the amount of emitted light is called the average reduction rate. The factors that determine this average reduction rate are the absorption of light during the diffuse reflection on the reflective surface inside the reflective housing, the number of diffuse reflections, the reflective housing, and the reflection before the light reaches the measurement unit. The color, shape and material of the connecting portion interposed between the housing and the measuring unit, the radiation of the light emitted from the light source, the hole diameters of the entrance and the exit, the distance from the entrance to the exit, the entrance and the There is an angle with respect to the optical axis of the light source of the facing surface of the exit, and the distance between the entrance and the exit and the facing surface, etc., the average reduction rate in this aspect is at least until each light reaches the measurement unit. It is determined by the absorption of light at the time of the diffuse reflection on the reflection surface and the number of times of the diffuse reflection.

  In the present disclosure, the smaller the ratio of the emitted light amount to the emitted light amount, the larger the average reduction rate. This average reduction rate may be expressed as a percentage of the amount of light lost until the amount of emitted light is reached, for example, when the amount of emitted light is 100%. Further, it may be expressed as a quotient obtained by dividing the amount of emitted light by the amount of emitted light, and this quotient may be expressed in logarithmic display. Alternatively, the quotient obtained by dividing the amount of emitted light by the amount of emitted light may be expressed as a number obtained by removing the negative sign (“−”) from the value expressed in logarithm (this value becomes a negative number). Whichever method is used, the larger the value, the larger the average reduction rate.

  Here, the average reduction rate from the same light source to the measurement unit is considered to be the same even if the light amounts of the light sources are different, as long as the wavelengths are the same. It is considered that the average reduction rate increases as the number of diffuse reflections of the optical path from the light source to the measurement unit increases.

  In this aspect, the average reduction rate of each of the plurality of light sources and the plurality of light sources that are determined by the number of times of light absorption and diffuse reflection at the time of diffuse reflection on the reflection surface until each light reaches the measurement unit. The position of the entrance is set so that the amount of emitted light corresponding to each light source falls within a certain range based on the amount of light emitted from the light source. Here, the “fixed range” is not generally determined because it differs depending on the measuring device, but it is determined by the gain adjustment in the measuring unit 30 used and the current value of the light source set by the light amount adjusting unit. It is desirable that the light quantity value of each light is adjusted to a substantially constant value by one or both of the light quantity adjustments of the light source. This range can be set such that the maximum emitted light amount is 10 times or less than the minimum emitted light amount. As a result, even if light sources with different light emission amounts are used, the measuring unit can receive a light amount within a certain range suitable for measurement without causing insufficient light amount or conversely light saturation. Note that the light emission amount and the emitted light amount are light amount values represented by a value serving as an index of the light amount, and the measurement method and display method thereof are not particularly limited, but for example, calculated by an optical spectrum analyzer or calculated by optical simulation. It may be a value that is set.

<Second mode>
In a second aspect of the present disclosure, in addition to the configuration of the first aspect, the light emission amount of each light source is adjusted so that the emitted light amount corresponding to each light source falls within a range narrower than the certain range. A possible light quantity adjusting unit is provided.

  In the optical measuring device of this aspect, for example, before adjusting the light emission amount of each light source, to confirm the emitted light amount in advance, based on this emitted light amount, by adjusting the light emission amount of each light source by the light amount adjustment unit, It is possible to further suppress the variation in the amount of light emitted from the light of each light source.

  As the adjustment of the light emission amount of each light source, for example, when LEDs are used for a plurality of light sources, the light emission amount of each light source can be adjusted by setting a different current value for each LED by the light amount adjustment unit. There is no particular limitation as long as the amount of light emission can be adjusted. Here, the “narrow range” varies depending on the measuring device and is not generally determined, but for example, the maximum emitted light amount can be three times or less than the minimum emitted light amount.

<Third aspect>
In the third aspect of the present disclosure, in addition to the configuration of the first or second aspect, the plurality of light sources emit light having different wavelengths.

  With such light sources having different wavelengths, for example, light having a wavelength (referred to as a main wavelength) having a sensitivity characteristic (for example, absorption characteristic) with respect to a certain measurement target is obtained from one light source, and a background value is obtained from another light source. It is also possible to obtain light having a wavelength (referred to as a sub-wavelength) for obtaining the light.

  When the light emission amounts of the plurality of light sources having different wavelengths are different from each other, the positions of the entrances corresponding to the plurality of light sources can be set by the configuration of the first aspect so that the emission light amount can be kept within a certain range. it can.

<Fourth aspect>
In a fourth aspect of the present disclosure, in addition to the configuration of the third aspect, at least two of the plurality of light sources emit light having wavelengths having sensitivity characteristics for different measurement targets.

  In the optical measuring device of this aspect, it is possible to measure at least two types of measurement targets by the at least two light sources. When the light emission amounts of such at least two light sources are different, the positions of the entrances corresponding to the plurality of light sources can be set by the configuration of the first aspect, and the emitted light amount can be kept within a certain range.

<Fifth aspect>
According to a fifth aspect of the present disclosure, in addition to the configuration according to any one of the first to fourth aspects, each of the plurality of entrance ports and the exit port has the average as the light from the light source with the larger light emission amount. It is provided at a position where the rate of decrease increases.

  For example, as described above, the average reduction rate increases as the number of diffuse reflections from the light source to the measurement unit increases, but the number of diffuse reflections increases as the optical path length from the light source to the measurement unit increases. To be Therefore, by arranging the entrance connected to the light source with a large amount of light emission farther from the measurement unit, and making the entrance connected to a light source with a smaller amount of light emission closer, the output light amount can be kept within a certain range. .

<Sixth aspect>
In a sixth aspect of the present disclosure, in addition to the configuration of the fifth aspect, each of the plurality of entrance ports and the exit port is configured such that light from a light source with a large amount of emitted light is reflected by the reflection surface up to the measurement unit. It is provided at a position where the diffuse reflection increases.

  For example, as described above, the greater the diffuse reflection of the optical path from the light source to the measurement unit, the greater the average reduction rate. Therefore, by increasing the number of times of diffuse reflection of a light source with a large amount of light emission and decreasing it with a light source with a small amount of light emission, the amount of emitted light can be kept within a certain range.

<Seventh mode>
According to a seventh aspect of the present disclosure, in addition to the configuration according to any one of the first to sixth aspects, a gain adjusting unit that adjusts the amount of light received by the measuring unit is provided, and the certain range is the gain. This is a range of light amount in which each of the emitted light amounts can be adjusted to a substantially constant value by the adjusting unit.

  Here, the range of this light amount varies depending on the light receiving characteristics of the measuring unit, but in many cases, the maximum light receiving amount is within a predetermined multiple of the minimum light receiving amount, specifically within about three times. desirable. Within such a range, the gain adjustment unit can adjust the gain of the measurement unit to a substantially constant value, and can prevent the measurement result from being affected by the difference in the light amount of the light source. Here, the fact that they are substantially constant for a plurality of values means that these values are not strictly constant, but the difference between these values does not have a substantial effect on the measurement result. It is a degree.

  The method of adjusting the gain by the gain adjusting unit is not particularly limited. For example, different gain adjustment may be performed for each light source.

<Eighth aspect>
An eighth aspect of the present disclosure is, in addition to the configuration according to any one of the first to seventh aspects, a portion interposed between the measurement unit and the emission port and having a light amount higher than that of the reflection surface. It has a measuring connection with a surface with a large reduction rate.

  For example, when an LED is used as a light source, since the light quantity has a characteristic that it changes depending on the temperature, it is necessary to provide a temperature adjusting section such as a temperature adjusting block around the light source. Therefore, there is a part having a certain thickness between the emission port and the measurement part, and the measurement part and the reflection housing are connected via this part. This part is called the measurement connection.

  The distance (thickness) of the measurement connecting portion, and especially the color thereof, are factors that increase the light reduction rate. Since the reflectance of the measurement connection is significantly lower than the reflectance of the reflective housing, the absorption of light during diffuse reflection at the measurement connection and the number of diffuse reflections are the main factors that determine the average reduction rate. sell. Depending on the color, material, or shape of the measurement connection or the reflection housing, for example, the reflection housing has a reflectance of 95%, whereas the measurement connection has a reflectance of 5%. In this aspect, the average reduction rate is determined in consideration of the number of times of light absorption and diffuse reflection at the time of diffuse reflection on the surface of the measurement connection part from the emission port to the measurement part. In this way, based on the average reduction rate of each of the plurality of light sources and the light emission amount of each of the plurality of light sources in consideration of the reduction of the amount of light on the surface of the measurement connection portion, the emitted light amount corresponding to each light source is within a certain range. As described above, the respective entrances are located so that

  Even if the temperature control unit is not provided as described above, it is necessary to provide the measurement connection unit depending on the positional relationship between the light source, the reflective casing, the measurement unit, and the like, and their shapes.

<Ninth Mode>
A ninth aspect of the present disclosure is a portion interposed between each of the plurality of light sources and each of the plurality of incident ports, in addition to the configuration according to any one of the first to eighth aspects, It has a surface that has a greater reduction rate of the amount of light than the reflective surface.

  Similar to the measurement connection section described above, there is a portion having a certain thickness between each of the plurality of light sources and the reflection housing, and each of the plurality of light sources and the reflection housing has this portion. Will be contacted via each. This portion is called a light source connecting portion.

  The distance (thickness) of the light source connecting portion and particularly its color are factors that increase the light reduction rate. Since the reflectance of the light source connection is significantly lower than the reflectance of the reflective housing, the number of light absorptions and diffuse reflections during the diffuse reflection at the light source connection is the main factor that determines the average reduction rate. obtain. Depending on the color, material, or shape of the light source connection portion or the reflection housing, for example, the reflectance of the reflection housing is 95%, whereas the reflectance of the light source connection portion is 5%. In this aspect, the average reduction rate is determined in consideration of the number of times of light absorption and diffuse reflection at the time of diffuse reflection on the surface of the light source connecting portion from each of the plurality of light sources to the reflection housing. As described above, based on the average reduction rate of each of the plurality of light sources and the light emission amount of each of the plurality of light sources in consideration of the reduction of the amount of light on the surface of the light source connection portion, the emitted light amount corresponding to each light source is within a certain range. As described above, the respective entrances are located so that

  In addition, when the measurement connection part is further provided between the measurement part and the emission port, the average reduction rate is determined in consideration of the decrease in the light amount on the surface of the measurement connection part.

<Tenth aspect>
In a tenth aspect of the present disclosure, in addition to the configuration according to any one of the first to ninth aspects, the reflection housing has a perforated surface provided with the plurality of entrance ports and the exit port, The box-like shape is provided with a facing surface facing the perforated surface and a connecting surface connecting the perforated surface and the facing surface.

  The box shape in this aspect is not limited to a rectangular parallelepiped shape, but refers to a shape having an internal space defined by a flat surface or a curved surface in front, rear, upper, lower, left and right. The flat surface or the curved surface may be appropriately provided with an opening such as a hole or a slit that connects the internal space and the outside. The reflective housing of this aspect is provided with a perforated surface, a facing surface, and a contact surface as such a plane or curved surface, and in particular, the perforated surface is provided with a plurality of entrances and exits as such openings. ing. Then, the inner surface of each of the perforated surface, the facing surface, and the communication surface serves as the above-described reflective surface.

  Here, the plurality of entrances and exits are provided on the same surface having a hole. The perforated surface is preferably a flat surface due to the configuration of the optical measuring device, but in that case, the optical axis of the light source toward the entrance is parallel and opposite to the optical axis from the exit to the measurement unit. . That is, the light from the light source enters the inside of the reflection housing at a right angle from the entrance, undergoes diffuse reflection inside, and is emitted at a right angle from the exit to reach the measurement unit. Such a bent optical path is realized by a reflection housing having a simple box-shaped structure without the need for a configuration like an optical fiber.

<Eleventh mode>
According to an eleventh aspect of the present disclosure, in addition to the configuration of the tenth aspect, in the facing surface, a portion where the optical axis of the light source with the smallest light emission amount among the plurality of light sources in the reflection housing first contacts , Inclined toward the emission port.

  In other words, the optical axis of the light source with the smallest amount of light emission is such that the facing surface that comes into contact with and is first in contact with from the entrance is inclined toward the exit. In other words, the facing surface faces the emission port. Therefore, the optical axis of the reflected light goes to the emission port, and reaches the emission port without being reflected too many times in the reflection housing. Therefore, as a result, the number of times of diffuse reflection before reaching the measurement unit is reduced, and the average reduction rate is relatively small. Therefore, a light source with the smallest light emission amount, for example, a light source with an extremely small light amount as compared with other light sources, can be arranged so as to be defined in this mode.

<Twelfth mode>
In a twelfth aspect of the present disclosure, in addition to the configuration of the tenth or eleventh aspect, the optical axis of the light source with the largest light emission amount among the plurality of light sources in the reflective housing is first contacted with the facing surface. The contact portion is perpendicular to the optical axis.

  In other words, the optical axis of the light source with the largest amount of light emission is perpendicular to the optical axis of the facing surface that comes into contact with the light source and comes into contact with it first. Therefore, since the optical axis of the reflected light is completely opposite to the original optical axis, the reflected light along the optical axis does not go directly to the emission port but to the emission port through diffuse reflection in the reflective housing. And so on. Therefore, as a result, the number of diffuse reflections to reach the measurement unit is increased and the average reduction rate is increased, as compared with the case where only the reflection along the optical axis is taken to the emission port. Therefore, a light source having the largest light emission amount, for example, a light source having an extremely large light amount as compared with other light sources can be arranged so as to be defined in this mode.

<Thirteenth mode>
In a thirteenth aspect of the present disclosure, in addition to the configuration of the twelfth aspect, the distance between the entrance corresponding to the light source with the largest light emission amount and the portion where its optical axis first abuts on the facing surface is It is shorter than the distance between an entrance corresponding to a light source other than the light source and its optical axis that first comes into contact with the facing surface.

  In this aspect, the distance between the entrance corresponding to the light source with the largest amount of light emission and the part where its optical axis first abuts on the facing surface is shorter than the distance with other light sources, resulting in the largest light emission. Since the number of times of diffuse reflection required for the light from the light source to reach the measurement unit is larger than the number of times of diffuse reflection of other light sources, the average reduction rate becomes large. Therefore, a light source having the largest light emission amount, for example, a light source having an extremely large light amount as compared with other light sources can be arranged so as to be defined in this mode.

<Fourteenth aspect>
In a fourteenth aspect of the present disclosure, in addition to the configuration of any one of the tenth to thirteenth aspects, a portion of the facing surface facing the emission port is parallel to the perforated surface.

  In this aspect, by making the portion of the facing surface of the reflective housing facing the emission port parallel to the perforated surface, the light reaches the emission port as perpendicularly as possible, and the measurement is performed from the emission port. The reduction due to absorption at the time of diffuse reflection on the inner wall (for example, the measurement connection portion in the eighth aspect) of the portion up to the portion is avoided as much as possible.

<Fifteenth aspect>
In a fifteenth aspect of the present disclosure, in addition to the configuration according to any one of the first to fourteenth aspects, in reflection of light on the reflection surface of the reflection housing, diffuse reflection is dominant over specular reflection. , Shape or material, or any two or all of them.

  For example, white is most suitable as a color in which diffuse reflection is superior to specular reflection in light reflection. As a shape in which diffuse reflection is superior to specular reflection in light reflection, for example, a surface whose surface is appropriately roughened is most suitable. A synthetic resin such as ABS resin or highly reflective polypropylene resin, which is resistant to deterioration by ultraviolet rays, is suitable as a material in which diffuse reflection is superior to specular reflection in light reflection.

<Main part of optical measuring device>
FIG. 1 is a side partial cross-sectional view of a main part of an optical measuring device 10 according to an embodiment of the present disclosure. The optical measuring device 10 includes a light source 20 that emits light downward and a measuring unit 30 that receives light from below. The light source 20 is composed of an LED that emits light of a predetermined wavelength. The measuring unit 30 is composed of a photodiode. In the present embodiment, five types of light sources 20 are provided and two types of measuring units 30 are provided as will be described later, but since this figure is shown by the I-I cross section shown in FIG. Only one of each of the upper light source 20 and the measuring part 30 is shown.

  Below the light source 20, the light source connecting portion 52, which is a hole portion for connecting the light source 20 and the reflective housing 40 to allow the light emitted from the light source 20 to pass, and the measuring portion 30 and the reflective housing 40, are connected. A temperature adjusting section 50 is provided in which a measurement connecting section 51, which is a hole for passing light to the section 30, is provided. The temperature control unit 50 is a black black heating element equipped with a heater and a thermostat and generates heat when energized. The temperature adjustment unit 50 adjusts the temperature of the light source 20 to a temperature suitable for a predetermined measurement. Further, the purpose of this temperature adjustment is to prevent the fluctuation of the light amount of the light source, and it is sufficient that the temperature can be adjusted to a certain predetermined temperature, and for example, it can be adjusted to a temperature suitable for the reagent used for the measurement. The inner space formed by the light source 20, the measurement unit 30, the light source connection unit 52, the measurement connection unit 51, and the reflection housing 40 is a sealed space.

  For example, when an LED is used as the light source 20, there is a characteristic that the amount of light varies depending on the temperature. Therefore, in order to keep the temperature of the light source 20 constant, a temperature control unit 50 such as a temperature control block is provided around the light source 20. There is a need. Further, since such a temperature adjusting unit 50 includes a heat source such as a resistance, a certain thickness is generated, and when the temperature adjusting unit 50 is provided between the light source 20 and the reflection housing 40, The temperature control unit requires a connection unit for connecting the light source or the measurement unit to the reflective housing.

  In the present embodiment, the reflectance at the light source connection portion 52 and the measurement connection portion 51 is about 5%, which is significantly lower than the reflectance at the reflection housing 40 of 95%. Therefore, the light source connection portion 52 and the measurement connection portion. The number of times of light absorption and diffuse reflection at the time of diffuse reflection at 51 is the main factor that determines the average reduction rate.

  Below the temperature control unit 50, a reflection housing 40 including a substantially rectangular parallelepiped box portion 40A having an open upper portion and a flat plate-shaped lid portion 40B closing the opened upper portion is installed. The upper surface of the lid portion 40B is in surface-to-surface contact with the lower surface of the temperature adjusting portion 50. The lower surface of the lid portion 40B is a perforated surface 41, and five entrances 42 (only one is shown in the drawing) and two exits 43 (only one is shown in the drawing). .) Has been formed. The entrance 42 communicates with the light source 20 through the light source connecting portion 52 of the temperature adjusting portion 50. The emission port 43 communicates with the measurement unit 30 via the measurement connection unit 51 described above. A test tool as a measurement target 80 is located between the measurement connection section 51 and the measurement section 30.

  As the test tool, for example, a holder capable of impregnating a specimen such as a test paper is used. Further, a unit or device formed of a light-transmissive material and having a space capable of containing a liquid as a sample may be used as the test tool as the measurement target 80.

  The box portion 40A of the reflection housing 40 corresponds to the bottom surface, is a facing surface 44 facing the perforated surface 41, and a side surface surrounding the perimeter of the facing surface 44, and connects the perforated surface 41 and the facing surface 44. And a contact surface 45 for connecting. The reflective housing is formed of a white ABS resin or a highly reflective polypropylene resin that is hard to undergo ultraviolet deterioration and has a high reflectance and is positively diffuse-reflected. 41, the facing surface 44, and the connecting surface 45 are all reflecting surfaces 46 that reflect the light of the light source 20.

  As shown in the bottom perspective view of FIG. 2, the reflection housing 40 is screwed to the bottom surface of the temperature control unit 50 by four mounting portions 40C that are provided on the side of the box portion 40A. When the box portion 40A is removed by releasing the screwing of the mounting portion 40C, the perforated surface 41 as the reflecting surface 46 corresponding to the bottom surface of the lid portion 40B is visually recognized as shown in the bottom perspective view of FIG. It The perforated surface 41 is formed with five entrance ports 42 and two exit ports 43. These five entrance ports 42 are arranged at positions corresponding to the vertices of a regular pentagon, and the farthest from the exit port 43 is the first entrance port 42A, and the exit port 43 is a little more than that. The second entrance port 42B and the third entrance port 42C are arranged in the vicinity, and the fourth entrance port 42D and the fifth entrance port 42E are arranged closest to the exit port 43. Of the two emission ports 43, the left-hand side of the drawing is the measurement-use emission port 43A, and the right-hand side of the drawing is the reference-use emission port 43B.

  FIG. 4 schematically shows the positional relationship between the light source 20 and the measurement unit 30, and the entrance 42 and the exit 43. On the perforated surface 41 as the reflecting surface 46, the five entrance ports 42 and the two exit ports 43 are formed as described above.

  20 A of 1st light sources which irradiate the light of wavelength 810nm are located in the position of 42 A of 1st entrances. The wavelength of the first light source 20A can be used as a sub-wavelength in measurement of various items. A second light source 20B that emits light having a wavelength of 405 nm is installed at the position of the second entrance 42B. A third light source 20C that emits light having a wavelength of 660 nm is installed at the position of the third entrance 42C. The wavelength of the third light source 20C can be used as the dominant wavelength in the measurement of creatinine and uric acid. A fourth light source 20D that emits light having a wavelength of 610 nm is installed at the position of the fourth entrance 42D. A fifth light source 20E that emits light having a wavelength of 556 nm is installed at the position of the fifth entrance 42E. The wavelength of the fifth light source 20E can be used as the dominant wavelength in the measurement of calcium. Among these light sources 20, the first light source 20A has the largest light emission amount, the second light source 20B and the third light source 20C have the second largest light emission amount, and the fourth light source 20D and the fifth light source 20E have the smallest light emission amount. . Note that each wavelength described above is merely an example, and the light source 20 that emits light of other wavelengths may be installed in any of the entrance ports 42.

  At a position passing from the measurement emission port 43A through the measurement connection part 51, there is a measurement part 30 that receives the light emitted to the measurement target 80 (see FIG. 1), and a measurement sensor 31 that is a photodiode is installed. There is. A reference sensor 32, which is a photodiode, is installed at a position passing from the reference emission port 43B through the measurement connection portion 51, which is the measurement unit 30 that receives the emitted light as it is.

<Transmission of light inside the reflective housing>
The transmission of light inside the reflection housing 40 will be described with reference to the schematic diagrams of FIGS. 5 and 6. The facing surface 44 serving as the reflecting surface 46 of the reflective housing 40 is a distal parallel surface 44A that is farthest from the exit port 43 and is parallel to the perforated surface 41, and a proximal surface that is closest to the exit port 43 and is parallel to the perforated surface 41. It is composed of a parallel surface 44C and an inclined surface 44B which is an inclined surface connecting the distal parallel surface 44A and the proximal parallel surface 44C. The distal parallel surface 44A faces the first entrance 42A. The inclined surface 44B faces the second entrance 42B and the third entrance 42C. The proximal parallel surface 44C faces the emission port 43.

  As described above, the first light source 20A that emits the largest amount of light is installed at a position corresponding to the first entrance 42A that is farthest from the measurement unit 30. The second light source 20B (and the third light source 20C, which will be hereinafter referred to as the “second light source 20B”) that has the second largest light emission amount after the first light source 20A has a second entrance 42B (and a third entrance) that is closer to the measurement unit 30. The opening 42C, which is represented by the "second entrance 42B" hereinafter), is installed at a position corresponding to the opening 42C. The fourth light source 20D (and the fifth light source 20E, which will be hereinafter referred to as the “fourth light source 20D”) having the smallest light emission amount is the fourth incident port 42D (and the fifth incident port 42E, which is the closest to the measuring unit 30). It is installed at a position corresponding to "the fourth entrance 42D".

  Then, as shown in FIG. 6, a distance D1 from the first entrance 42A to the distal parallel surface 44A, a distance D2 from the second entrance 42B to the inclined surface 44B, and a distance D4 from the fourth entrance 42D to the inclined surface 44B. The following relationship exists between the distance D3 and the distance D4 from the exit port 43 to the proximal parallel surface 44C.

  D1 <D2 <D3 <D4

  As described above, the optical axis α1 of the first light source 20A, which is the light source 20 having the largest amount of light emission, is perpendicular to the distal parallel surface 44A that is the first contact portion of the facing surface 44. The distance D1 between the first entrance 42A corresponding to the first light source 20A and the distal parallel surface 44A is shorter than the distances D2 and D3 between the other entrance 42 and the inclined surface 44B.

  Further, the inclined surface 44B, which is the portion of the facing surface 44 that first contacts the optical axis α2 of the second light source 20B having the next largest amount of light emission, is inclined toward the emission port 43.

  The inclined surface 44B, which is the portion of the facing surface 44 that first comes into contact with the optical axis α3 of the fourth light source 20D that is the light source 20 with the smallest amount of light emission, is also inclined toward the emission port 43.

  As described above, the light emitted from the first light source 20A, which is the light source 20 having the largest light emission amount, with the optical axis α1 becomes the reflected light γ1 which is vertically reflected by the distal parallel surface 44A. Since the distance D1 from the first entrance 42A to the distal parallel surface 44A is shorter than the distances D2 and D3 between the other entrance 42 and the inclined surface as described above, the light is emitted from the first light source 20A. The light (including the scattered light β1 from the first light source 20A) has the largest number of diffuse reflections (including the light source connection portion 52, the perforated surface 41 as the reflection surface 46, the connection surface 45, and the measurement connection portion 51). .) To reach the measurement unit 30 as measurement light δ. Therefore, as a result, the light from the first light source 20A has the largest number of diffuse reflections, and thus the average reduction rate is the largest. In addition, if the average reduction rate of the light from the first light source 20A is the largest, the optical axis α1 of the first light source 20A is not necessarily perpendicular to the optical axis α1 at the portion of the facing surface 44 that first abuts. For example, the optical axis α2 of the second light source 20B may be a gradual inclined surface as compared with the inclined surface 44B that is the first contact portion of the facing surface 44.

  The light emitted from the second light source 20B, which is the light source 20 having the next largest amount of light emission, with the optical axis α2 becomes the reflected light γ2 that is reflected by the inclined surface 44B toward the emission port 43. Here, the distance D2 from the second entrance 42B to the inclined surface 44B is intermediate between the distances D1 and D3 described above, and the light emitted from the second light source 20B (including the scattered light β2 from the second light source 20B). Is measured light δ after being subjected to the next highest number of diffuse reflections of the first light source 20A (including the light source connection portion 52, the perforated surface 41 as the reflection surface 46, the connection surface 45, and the measurement connection portion 51). As a result, the measurement unit 30 is reached. Therefore, as a result, the light from the second light source 20B has the second highest number of diffuse reflections after the first light source 20A, and thus the average reduction rate also becomes the second highest after the first light source 20A.

  Then, the light emitted from the fourth light source 20D, which is the light source 20 having the smallest light emission amount, with the optical axis α3 is reflected light γ3 that is reflected by the inclined surface 44B toward the emission port 43. Since the distance D3 from the fourth entrance 42D to the inclined surface 44B is longer than the distances D1 and D2 described above, the light emitted from the fourth light source 20D (including the scattered light β3 from the fourth light source 20D). Passes through the least number of times of diffuse reflection (including diffuse reflection at the light source connection portion 52, the perforated surface 41 as the reflection surface 46, the connection surface 45, and the measurement connection portion 51), and reaches the measurement portion 30 as the measurement light δ. . Therefore, as a result, the light from the fourth light source 20D has the largest number of diffuse reflections, and thus the average reduction rate is the smallest.

<Function block>
FIG. 7 shows a functional block diagram of the optical measuring device 10. The control unit 60 controls each unit of the optical measuring device 10. The control unit 60 has a hardware configuration, which will be described later, to adjust the gain of the light received by the measuring unit 30, a gain adjusting unit 70 that adjusts the light emission amount of the light source 20, and a temperature in the temperature adjusting unit 50. Functions as a temperature control unit 72 for adjusting the temperature.

  The gain adjusting unit 70 may perform the correction by multiplying the actually received light amount by a predetermined coefficient for each light source 20 to be used. When the wavelength is different for each light source, the gain adjusting unit 70 consequently performs the correction for each wavelength. The light amount adjustment unit 71 adjusts the light emission amount by supplying a predetermined amperage of electric power to each light source 20 to be used. The temperature control unit 72 adjusts the light source 20 to a predetermined constant temperature via a thermostat (not shown).

  The light source 20 irradiates the inside of the reflection housing 40 with a predetermined amount of light of a predetermined wavelength by the electric power supplied from the light amount adjusting unit 71. The measurement unit 30 receives the light emitted from the reflective housing 40 and applied to the measurement target 80.

<Hardware configuration of control unit>
As shown in the hardware configuration of FIG. 8, the control unit 60 includes a CPU (Central Processing Unit) 61, a ROM (Read Only Memory) 62, a RAM (Random Access Memory) 63, and a storage 64. The components are connected to each other via a bus 69 so that they can communicate with each other.

  The CPU 61 is a central processing unit that executes various programs and controls each unit. That is, the CPU 61 reads the program from the ROM 62 or the storage 64 and executes the program using the RAM 63 as a work area. The CPU 61 controls the above-described components and performs various arithmetic processes according to a program recorded in the ROM 62 or the storage 64.

  The ROM 62 stores various programs and various data. The RAM 63 temporarily stores a program or data as a work area. The storage 64 includes an HDD (Hard Disk Drive), an SSD (Solid State Drive), or a flash memory, and stores various programs including an operating system and various data. In this aspect, the ROM 62 or the storage 64 stores a program related to measurement and various data. Further, the measurement data can be stored in the storage 64.

  The control unit 60 functions as a gain adjusting unit 70, a light amount adjusting unit 71, and a temperature controlling unit 72 as shown in FIG. 7 in the optical measuring device 10 by the CPU 31 of the above hardware configuration executing the program. To do.

<Summary of Embodiment>
As described above, in the optical measuring device 10 according to the present embodiment, the reflective housing 40 for transmitting the light from the light source 20 to the measuring unit 30, the light source connecting unit 52, and the measuring connecting unit 51 from the light source 20 to the measuring unit 30. Covers. In the reflection housing 40, the light source 20 having a large amount of light emission is placed away from the measurement unit 30, and the light source 20 having a small amount of light emission is installed near the measurement unit 30. Further, light is diffusely reflected by the inner reflection surface 46 of the reflection housing 40, the light source connection portion 52, and the measurement connection portion 51.

  That is, the respective lights from the plurality of light sources 20 are made to enter the inside of the reflective housing 40 via the light source connection portion 52, and further emitted to the measurement portion 30 via the measurement connection portion 51. As a result, the amount of light decreases from the light source 20 to the measurement unit 30 due to absorption during diffuse reflection inside the reflection housing 40, the light source connection unit 52, and the measurement connection unit 51, and the amount of light in a certain range of values. The optical measurement is performed by irradiating the measuring section 30 with each of the light. Therefore, it is cheaper because the box-shaped reflection housing 40 is used instead of the transmission means such as the optical fiber, and the box-shaped reflection housing 40 does not require a wide space for handling like the optical fiber.

  Further, in the present embodiment, the smaller the light emitting amount of the light source 20 is, the smaller the average reduction rate of the light from the light source 20 due to the absorption at the time of diffuse reflection until the light from the light source 20 reaches the measurement unit 30 is smaller. It is placed in such a position that That is, the magnitude relationship between the amount of light emitted from the light source 20 and the average reduction rate that decreases due to absorption during diffuse reflection until the light from the light source 20 reaches the measurement unit 30 is the same.

  Accordingly, the average reduction rate of each of the light sources 20 and the measurement unit 30 is appropriately adjusted, so that an appropriate amount of light emission, that is, light from the light sources having different amounts of light emission is appropriate in the measurement unit 30. The light emission is adjusted and transmitted.

  Further, regarding the light source 20 (for example, the first light source 20A having an extremely large light emission amount) that needs to further reduce the light emission amount, the reflection housing 40 is provided in order to increase the average reduction rate from the light source 20 to the measurement unit 30. For example, a distal parallel surface 44A perpendicular to the optical axis and having a short distance to the facing surface 44 can be provided as described above.

  On the contrary, for the light source 20 (for example, the fourth light source 20D or the fifth light source 20E whose emission amount is extremely small) which does not want to reduce the emission amount so much, in order to reduce the average reduction rate from the light source 20 to the measuring unit 30. The reflective housing 40 may be provided with the inclined surface 44B inclined to the measuring unit 30 as described above.

  Since the amount of light emission required for the measurement target 80 is appropriate, the magnitude of the light emission amount and the magnitude of the average reduction rate do not necessarily have to be proportional to each other, and the average light emission amount appropriate for the measurement target 80 is obtained. Each light source 20 may be arranged at a position where the reduction rate is obtained.

  In the following description, common reference numerals are attached to the configurations common to the example and the comparative example for convenience of reference, but the same reference numerals are not always the same configurations. In particular, regarding the first light source 20A to the fifth light source 20E, those at the same position have the same name (see FIG. 4), but the same light source 20 is used in the example and the comparative example. Not necessarily.

<Comparative example>
The results of using the reflective casing 40 according to the comparative example before adjusting the average reduction rate for each light source 20 are shown below. The optical measuring device 10 in this comparative example has a light source connecting portion 52 and a measuring connecting portion 51.

  Regarding the first light source 20A to the fifth light source 20E in this comparative example, the wavelength (nm), the light emission amount (nW), the diameter of the corresponding entrance 42 (unit: mm), the linear distance between the light source 20 and the measurement unit 30 ( mm), the inclination angle (°) of the facing surface 44 with respect to the optical axis (α1 to α3) passing through the entrance 42, the distance (mm) between the entrance 42 and the facing surface 44, and the distance between the light source 20 and the facing surface 44 ( mm) was as shown in Table 1 below.

  The diameter of the exit port 43 is 3 mm, the inclination angle of the facing surface 44 with respect to the optical axis of the measurement light δ (see FIG. 5) exiting from the exit port 43 is 90 °, and the distance between the exit port 43 and the facing surface 44 is 10 mm. The distance between the measurement unit 30 and the facing surface 44 was 19 mm. Incidentally, the difference between the "distance between the light source 20 and the facing surface 44" and the "distance between the entrance 42 and the facing surface 44" becomes the distance of the light source connecting portion 52, and this value for each light source is shown in Table 1 above. As shown in FIG. Further, the difference between the “distance between the measurement unit 30 and the facing surface 44” and the “distance between the emission port 43 and the facing surface 44” becomes the distance of the measurement connecting portion 51, and the value thereof is 9 mm (= 19 mm−10 mm). )Met.

  Here, the amount of light emitted from each light source 20 and the amount of light emitted from the measurement unit 30 were measured or calculated as follows. The luminescence amount was measured by AQ-6315A OPTICAL SPECTRUM ANALYZER (Yokogawa measurement). The emitted light amount was calculated by multiplying each emission amount by the reduction rate from each light source 20 to the measurement unit 30 obtained by the illumination Simulator CAD ver.1.00.000 (best medium). In Lighting Simulator CAD ver.1.00.000, the light source was simulated as a point light source, and the calculation was performed assuming that the light source did not absorb light. The calculation was performed assuming that the reflectance of the reflective housing 40 is 95% (the reduction rate is 5%), and the reflectances of the light source connection portion 52 and the measurement connection portion 51 are both 5% (the reduction rate is 95%). The results are shown in Table 2 below.

  As shown in Table 2 above, the maximum light emission amount (first light source 20A, 6.0 nW) was 11.11 times the minimum light emission amount (second light source 20B-5 light source 20E, 0.54 nW).

  With respect to these light sources 20, the amount of emitted light (pW) in the measurement unit 30 was as shown in Table 2 above. Further, the value obtained by dividing each emitted light amount by the minimum emitted light amount is listed in the column of "relative ratio" in Table 2 above. That is, the maximum emitted light amount in the measurement unit 30 was 0.1450 pW of the first light source, which was 29.59 times the minimum emitted light amount of 0.0049 pW of the second light source 20B. The relative ratio of the emitted light amount exceeds 29 times, which is well above the range (roughly within 10 times) that can be kept within a certain range by adjusting the light amount of the light source 20 by adjusting the current value and adjusting the gain. It was In addition, at this time, none of the emitted light amounts of the first light source 20A to the fifth light source 20E satisfy the light amount necessary for measuring the measurement target 80.

  By the way, the average reduction rate expressed by the common logarithm of the value obtained by dividing the light emission amount by the emitted light amount is 5.04 for the second light source 20B and is the maximum, and the third light source 20C and the fourth light source 20D are as shown in Table 2 above. Was 5.03 and 4.82, respectively, and second, respectively, and the first light source 20A and the fifth light source 20E were 4.62, which was the minimum. From this result, in the comparative example, no particular relationship was found between the linear distance between the light source 20 and the measurement unit 30 and the average reduction rate.

<Example 1>
On the basis of the results of the comparative example, earnest studies have been made so that the emitted light amount of each light source falls within a certain range, and the wavelength (nm), the light emission amount (nW), and the corresponding incident light of the first light source 20A to the fifth light source 20E Diameter of the mouth 42 (unit: mm), linear distance between the light source 20 and the measuring unit 30 (mm), inclination angle (°) of the facing surface 44 with respect to the optical axis (α1 to α3) passing through the entrance 42, the entrance 42 The distance (mm) between the light source 20 and the facing surface 44 and the distance (mm) between the facing surface 44 and the light source 20 were adjusted as shown in Table 3 below.

  The diameter of the exit port 43 is 3 mm, the inclination angle of the facing surface 44 with respect to the optical axis of the measurement light δ (see FIG. 5) exiting from the exit port 43 is 90 °, and the distance between the exit port 43 and the facing surface 44 is 10 mm. The distance between the measurement unit 30 and the facing surface 44 was 20.7 mm. Incidentally, the difference between the “distance between the light source 20 and the facing surface 44” and the “distance between the entrance 42 and the facing surface 44” becomes the distance of the light source connecting portion 52, and this value for each light source is shown in Table 3 above. As shown in FIG. Further, the difference between the “distance between the measurement unit 30 and the facing surface 44” and the “distance between the emission port 43 and the facing surface 44” becomes the distance of the measurement connecting portion 51, and the value thereof is 10.7 mm (= 20. It was 0.7 mm-10 mm).

  The amount of light emitted from each light source 20 at this time was calculated in the same manner as in the comparative example described above. The results are shown in Table 4 below.

  As shown in Table 4, the maximum light emission amount (second light source 20B, 88.7 nW) was 17.74 times the minimum light emission amount (fifth light source 20E, 5.0 nW).

  With respect to these light sources 20, the amount of emitted light (pW) in the measurement unit 30 was as shown in Table 4 above. Further, the values obtained by dividing each emitted light amount by the minimum emitted light amount are listed in the "relative ratio" column of Table 4 above. That is, the maximum emitted light amount in the measurement unit 30 was 6.760 pW of the second light source 20B, and was 9.67 times the minimum emitted light amount of 0.699 pW of the third light source 20C. From the above, the relative ratio of the emitted light amount was within the range of 9.67 times and 10 times, and was a relative ratio of a range in which the light amount of the light source 20 was adjusted by adjusting the current value to be able to be kept in a substantially constant range. In addition, the emitted light amounts of the first light source 20A to the fifth light source 20E at this time satisfy the light amounts necessary for measuring the measurement target 80.

  By the way, the average reduction rate obtained in the same manner as in the comparative example is, as shown in Table 4 above, that the first light source 20A farthest from the measurement unit 30 has a maximum value of 4.57, and hereinafter, the second light source 20B has 4. 12, the third light source 20C has 4.00, the fourth light source 20D has 3.85, and the fifth light source 20E has 3.63. The rank of this average reduction rate was in agreement with the rank of the linear distance between the light source 20 and the measurement unit 30 (see Table 3).

<Example 2>
Based on the emitted light amount listed in Table 4, the light amount of the light source 20 was adjusted by adjusting the current value. Specifically, the emission amount after adjustment shown in Table 5 below was obtained by dividing each emission amount by the value listed in the "relative ratio" section in Table 4 above. The parameters other than the light emission amount are the same as those described in Table 3 of Example 1, and the description thereof will be omitted.

  First, as shown in Table 5, the adjusted light emission amount is maximum at 25.7 nW for the first light source 20A farthest from the measurement unit 30, 9.2 nW for the second farthest light source 20B, and then farthest. The third light source 20C has a value of 7.0 nW, the farthest fourth light source 20D has a decreasing value of 5.0 nW, and the closest fifth light source 20E has a minimum value of 2.8 nW. The maximum light emission amount (first light source 20A, 25.7 nW) was 9.17 times the minimum light emission amount (fifth light source 20E, 2.8 nW).

  With respect to these light sources 20, the amount of emitted light (pW) at the measurement unit 30 was as shown in Table 5 above. Further, the value obtained by dividing each emitted light amount by the minimum emitted light amount is listed in the column of "relative ratio" in Table 5 above. That is, the maximum emitted light amount in the measurement unit 30 is 0.705 pW of the second light source 20B, which is 1.05 times the 0.672 pW of the first emitted light source 20A, which is the minimum emitted light amount. It can be said that the amount of light emitted from the sample was almost constant. This minute difference in the amount of emitted light is adjusted by normal gain adjustment.

  The average reduction rate expressed in the same manner as in Table 4 is maximum at 4.58 for the first light source 20A farthest from the measuring unit 30, 4.12 for the second light source 20B farthest away, and the third farthest next. The light source 20C was 4.00, the farthest fourth light source 20D was 3.85, and the closest fifth light source 20E was 3.61. The rank of the average reduction rate matches the rank of the linear distance between the light source 20 and the measurement unit 30 (see Table 3), and also matches the rank of the light emission amount.

  INDUSTRIAL APPLICABILITY The present invention can be applied to an optical measuring device that allows light from a plurality of types of light sources to reach a measurement unit at one location and measures a measurement target for a plurality of items.

10 Optical Measuring Device 20 Light Source 20A First Light Source 20B Second Light Source 20C Third Light Source 20D Fourth Light Source 20E Fifth Light Source 30 Measuring Section 31 Measuring Sensor 32 Reference Sensor 40 Reflective Housing 40A Box Section 40B Lid Section 40C Mounting Section 41 Perforated surface 42 Entrance 42A First entrance 42B Second entrance 42C Third entrance 42D Fourth entrance 42E Fifth entrance 43 Exit 43A Measurement exit 43B Reference exit 44 Opposing surface 44A Far Parallel surface 44B inclined surface 44C proximal parallel surface 45 connecting surface 46 reflecting surface 50 temperature adjusting portion 51 measurement connecting portion 52 light source connecting portion 60 control portion 61 CPU
62 ROM
63 RAM
64 storage 69 bus 70 gain adjusting unit 71 light amount adjusting unit 72 temperature control unit 80 measurement target α1 to α3 optical axes β1 to β3 scattered light γ1 to γ3 reflected light δ measuring light

Claims (15)

A plurality of light sources that emit at least one different amount of light;
A measuring unit that measures a measurement target with light emitted from the plurality of light sources,
An optical measurement device comprising: a reflection housing into which the light emitted from the plurality of light sources is incident and the light diffusely reflected by an internal reflection surface is emitted to the measurement unit;
The reflective housing is
A plurality of entrances that are in communication with each of the plurality of light sources, are provided at different positions for each of the plurality of light sources, and light is incident to the inside from each of the plurality of light sources,
Diffuse reflection of the light incident from the plurality of entrances, and a reflecting surface that absorbs a part of the light when the diffuse reflection is performed,
An emission port that communicates with the measurement unit and that emits the light diffusely reflected by the reflection surface from the inside to the measurement unit,
For each of the plurality of light sources, in order to set the emitted light amount, which is the amount of light when the light emitted from each of the plurality of light sources reaches the measurement unit through the emission port, to a value within a certain range. Based on the average reduction rate that represents the rate of decrease of the amount of light emission of the light source reaches the measurement unit, and the amount of light emission of each of the plurality of light sources, each of the plurality of entrance ports with respect to the position of the exit port. Are placed in different positions,
The said measurement part is an optical measuring device which optically measures the said measuring object by irradiating the said measuring object with the said emitted light quantity.   The optical measurement device according to claim 1, further comprising a light amount adjustment unit capable of adjusting the light emission amount of each light source so that the emitted light amount corresponding to each light source falls within a range narrower than the predetermined range.   The optical measurement device according to claim 1, wherein the plurality of light sources emit light having different wavelengths.   The optical measuring device according to claim 3, wherein at least two of the plurality of light sources emit light having wavelengths having sensitivity characteristics with respect to different measurement targets.   5. Each of the plurality of entrance openings and the exit opening is provided at a position such that the average reduction rate becomes larger as the light from the light source with the larger light emission amount is provided. The optical measurement device according to item 1.   6. Each of the plurality of entrance ports and the exit port is provided at a position such that the light from the light source with the larger light emission amount causes the diffuse reflection by the reflecting surface to increase up to the measuring unit. The optical measuring device according to. The measurement unit includes a gain adjustment unit that adjusts the amount of light received.
The optical measuring device according to any one of claims 1 to 6, wherein the constant range is a range of light amount in which each of the received light amounts can be adjusted to a substantially constant value by the gain adjusting unit. .   8. The measurement connecting portion having a surface which is a portion interposed between the measurement portion and the emission port and has a larger reduction rate of light quantity than the reflection surface. The optical measurement device according to the item.   9. A portion interposed between each of the plurality of light sources and each of the plurality of entrances, having a surface having a larger light amount reduction rate than that of the reflecting surface. The optical measurement device according to item 1.   The reflection housing has a perforated surface on which the plurality of entrance ports and the exit port are provided, a facing surface facing the perforated surface, and a contact surface that connects the perforated surface and the facing surface. The optical measurement device according to any one of claims 1 to 9, which has a box shape including:   11. The portion of the facing surface, which is first contacted by the optical axis of the light source with the smallest light emission amount among the plurality of light sources in the reflection housing, is inclined toward the emission port. Optical measuring device.   The portion of the reflection housing, on which the optical axis of the light source with the largest light emission amount comes into contact first, of the plurality of light sources in the reflective housing is perpendicular to the optical axis. The optical measuring device described.   The distance between the entrance corresponding to the light source with the largest amount of light emission and the part where the optical axis of the light source first abuts on the facing surface is such that the entrance corresponding to a light source different from the light source and the optical axis thereof are opposite to each other. The optical measuring device according to claim 12, which is shorter than a distance from a portion that first comes into contact with the surface.   The optical measuring device according to any one of claims 10 to 13, wherein a portion of the facing surface facing the emission port is parallel to the perforated surface.   The reflection of light on the reflection surface of the reflection housing is formed by a color, a shape or a material in which diffuse reflection is dominant over specular reflection, or any two or all of them. The optical measuring device according to claim 14.