JP7036699B2 - Optical measuring device - Google Patents

Description

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

When using multiple types of test papers or multiple types of light sources corresponding to measurement items in a conventional optical measuring device, the light from each light source can be stored in one place by using multiple optical fibers provided for each light source. In some cases, a method of collecting and irradiating the measuring unit is adopted.

The following Patent Document 1 discloses a technique of reflecting light to irradiate a sample.

Further, Patent Document 2 below discloses a technique for measuring a reference light amount and a sample light amount using an integrating sphere.

Japanese Unexamined Patent Publication No. 03-194447 Special Publication No. 61-028292

When irradiating the measurement unit with light from multiple light sources using an optical fiber, the minimum bending radius is defined by the material of the optical fiber, so there is a limit to the miniaturization of the device in order to secure that space. .. In addition, the price of optical fiber is high, and the more types of light sources are used, the higher the manufacturing cost due to the optical fiber used. Therefore, the optical transmission system using an optical fiber is not suitable for a small and inexpensive device.

On the other hand, when irradiating the measurement unit with light from a light source using a reflection unit having a cheaper configuration without using an optical fiber, light from each light source having a different amount of light is transmitted to the measurement unit with an appropriate amount of light. There was a problem that it was difficult to do. That is, in the case of an inexpensive light source, the amount of light may vary depending on the light source used. If, for the light from each of such light sources, the light from the light source including the reflection unit (the reflection housing and the connection part connecting the reflection housing and the light source and the measurement unit) is indirectly sent to the measurement unit. Assuming that the average reduction rate of light (the rate at which light decreases by the time it reaches the measurement unit) in the housing (the housing for reaching) is the same, a light source with a small amount of light is used to detect the measurement target. It may not be possible to measure the measurement target because a satisfactory amount of light cannot be obtained. On the other hand, in the case of a light source having 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, a light receiving sensor). As described above, the amount of light may be too large or too small depending on the relationship between the amount of light of the light source, the sensitivity of the measuring unit, and the average reduction rate, which is the reason for designing a small and inexpensive optical measuring device. It was causing difficulties.

Therefore, an embodiment of the present invention is an optical measuring device using a reflection unit that transmits light from a plurality of light sources having different amounts of light to a measuring unit, at low cost and space saving, and appropriate light from each light source. The problem is to transmit the amount of light to the measuring unit.

In the first aspect of the present disclosure, a plurality of light sources having at least one different light emission amount and a plurality of light sources.
A measuring unit that measures a measurement target by light emitted from the plurality of light sources, and a measuring unit.
An optical measuring device including a reflective housing in which light emitted from the plurality of light sources is incident and diffusely reflected by an internal reflecting surface is emitted to the measuring unit.
The reflective housing is
A plurality of incident ports that are in contact 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 into the interior from each of the plurality of light sources.
A reflective surface that diffusely reflects light incident from the plurality of incident ports and absorbs a part of the light when diffusely reflected.
It is provided with an outlet that communicates with the measuring unit and emits the diffusely reflected light from the inside to the measuring unit on the reflecting surface.
A light source for each of the plurality of light sources in order to set the amount of emitted light, which is the amount of light emitted from each of the plurality of light sources when the light emitted from each of the plurality of light sources reaches the measurement unit via the outlet, to a value within a certain range. Based on the average reduction rate, which represents the rate at which the amount of light emitted from the light emitting amount decreases by the time it reaches the measuring unit, and the amount of light emitted from each of the plurality of light sources, each of the plurality of incident ports is relative to the position of the exit port. Are placed in different positions,
The measuring unit performs optical measurement of the measurement target by irradiating the measurement target with light at the amount of emitted light.

In the second aspect of the present disclosure, in the first aspect, the amount of light emitted by each of the light sources can be adjusted so that the amount of emitted light corresponding to each of the light sources falls within a range narrower than the certain range. It is equipped with an adjustment unit.

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

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

In the fifth aspect of the present disclosure, in any one of the first to fourth aspects, the average reduction rate of the light from the light source having a large amount of light emitted from each of the plurality of incident ports and the exit port is the same. It is installed in a position where it becomes large.

In the sixth aspect of the present disclosure, in the fifth aspect, the diffuse reflection by the reflecting surface is performed by the light from the light source having a large amount of light emitted from each of the plurality of incident ports and the exit port to the measuring unit. Is provided at a position where the number of lights increases.

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

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

In the ninth aspect of the present disclosure, in any one of the first to eighth aspects, the portion interposed between each of the plurality of light sources and each of the plurality of incident ports, and the reflective surface. It has a surface with a larger reduction rate of the amount of light than.

In the tenth aspect of the present disclosure, in any one of the first to ninth aspects, the reflective housing has a perforated surface provided with the plurality of incident ports and the exit port, and the perforated surface. It exhibits a box shape including a facing surface facing the surface and a connecting surface connecting the perforated surface and the facing surface.

In the eleventh aspect of the present disclosure, in the tenth aspect, the portion where the optical axis of the light source having the smallest light emission amount among the plurality of light sources in the reflection housing first abuts on the facing surface is the emission. It is tilted toward the mouth.

In the twelfth aspect of the present disclosure, in the tenth or eleventh aspect, the portion where the optical axis of the light source having the largest light emission amount among the plurality of light sources in the reflection housing first abuts on the facing surface is It is perpendicular to the optical axis.

In the thirteenth aspect of the present disclosure, in the twelfth aspect, the distance between the incident port corresponding to the light source having the largest light emission amount and the portion where the optical axis first abuts on the facing surface is the light source. The distance between the incident port corresponding to another light source and the portion where the optical axis thereof first abuts on the facing surface is shorter than the distance.

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

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

In the embodiment of the present invention, in the optical measurement, the light from the light source is reflected in the reflective housing to irradiate the measurement target, so that a member such as an optical fiber that guides the light to the measurement target becomes unnecessary, and the manufacturing cost is reduced. The cost can be reduced and the size of the device can be reduced.

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

In other words, in an optical measuring device that uses a reflection unit that transmits light from multiple light sources with different amounts of light to the measuring unit, the light from each light source is appropriate while reducing the manufacturing cost and downsizing of the device. It can be transmitted to the measuring unit with a large amount of light.

The main part of the optical measuring device is shown in a side sectional view. The main part of the optical measuring device is shown in the bottom perspective view. A bottom perspective view shows a state in which a part of the reflective housing is removed from the main part of the optical measuring device. The arrangement of the light source and the measuring unit is schematically shown. The transmission of light inside the reflective housing is schematically shown. The distance between the incident port and the facing surface is schematically shown. It is a functional block diagram of an optical measuring device. The hardware configuration of the control unit is shown in a block diagram.

<First aspect>
The optical measuring device according to the first aspect of the present disclosure includes a plurality of light sources having at least one different light emission amount, and a plurality of light sources.
A measuring unit that measures a measurement target by light emitted from the plurality of light sources, and a measuring unit.
An optical measuring device including a reflective housing in which light emitted from the plurality of light sources is incident and diffusely reflected by an internal reflecting surface is emitted to the measuring unit.
The reflective housing is
A plurality of incident ports that are in contact 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 into the interior from each of the plurality of light sources.
A reflective surface that diffusely reflects light incident from the plurality of incident ports and absorbs a part of the light when diffusely reflected.
It is provided with an outlet that communicates with the measuring unit and emits the diffusely reflected light from the inside to the measuring unit on the reflecting surface.
A light source for each of the plurality of light sources in order to set the amount of emitted light, which is the amount of light emitted from each of the plurality of light sources when reaching the measuring unit via the outlet, to a value within a certain range. Based on the average reduction rate, which represents the rate at which the amount of light emitted from the light emitting amount decreases by the time it reaches the measuring unit, and the amount of light emitted from each of the plurality of light sources, each of the plurality of incident ports is relative to the position of the exit port. Are placed in different positions,
The measuring unit performs optical measurement of the measurement target by irradiating the measurement target with light at the amount of emitted light.

In the optical measuring device of this embodiment, a plurality of light sources are provided. The type of the light source is not particularly limited, but for example, an LED or the like can be used. The plurality of light sources may include those having the same amount of light, but the amount of light of at least one light source is different from that of the other light sources. Further, although each light source emits light at different timings, it is possible to simultaneously emit a plurality of light sources for the purpose of increasing the amount of light, such as when a light source having a small amount of light is used.

The measurement target of this embodiment refers to a device that is actually irradiated with light for measurement, and includes a test tool capable of immersing or accommodating a sample (for example, a liquid such as blood).

The measuring unit receives light emitted from a plurality of light sources. The light received by the measuring unit is emitted from the light source, but the light from the light source is the reflection housing, the light source connection part that connects the reflection housing and the light source, and the measurement connection part that connects the reflection housing and the measurement unit. By repeating diffuse reflection on the surface of such a surface, it finally reaches the measurement unit. During this diffuse reflection, a part of the light is absorbed by the substance that reflected the light. By the time it reaches the measurement unit, light is absorbed during diffuse reflection on the reflective surface, and the light emitted from the light source is reflected without reaching the measurement unit depending on the path of the light. By repeating diffuse reflection and absorption generated at that time in the unit, there is a certain amount of light that is completely reduced before reaching the measurement unit, so the light with the reduced amount of light is irradiated to the measurement target. It becomes. Finally, of the light that irradiates the measurement target with the light whose amount of light is reduced, the transmitted or reflected light reaches the measurement unit. Therefore, of course, the measuring unit does not receive all the light emitted from the light source.

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

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

The measuring unit is not particularly limited as long as it can convert the received light amount into some quantitative signal such as an electric signal. For example, a photodiode can be used as this measuring unit. Further, the sensitivity of the measuring unit may differ depending on the wavelength, and in this embodiment, the positions of the incident port and the exit port can be set based on the sensitivity of the measuring unit.

The reflection housing is a member in which light is incident from a plurality of light sources, and the light is emitted to the measuring unit through internal reflection. The reflective housing is provided with an incident port, which is a hole through which the light of the light source is incident, at different positions corresponding to each of the plurality of light sources. Further, an exit port, which is a hole for emitting light to the measurement unit, is also provided. Further, the inner surface of the reflecting housing is a reflecting surface that diffusely reflects the light incident from the incident port to the exit port to reach the exit port.

In this embodiment, an incident port connected to a different light source is provided for each light source, but the light incident on the inside of the reflection housing from each incident port passes through diffuse reflection on the reflecting surface to the exit port. The reached portion is emitted to the measuring unit from the exit port connected to the measuring unit. During this period, the amount of light emitted, which is the amount of light from the light source, decreases due to the absorption of light during diffuse reflection on the reflective surface and the presence of light that is completely reduced before it finally reaches the measurement unit. The amount of light emitted from the light source and reaching the measuring unit is the amount of emitted light, which is the amount of light emitted as a result of the decrease. The rate at which the amount of light emitted decreases to the amount of emitted light is referred to as the average reduction rate. Factors that determine this average reduction rate are the absorption of light during diffuse reflection on the reflective surface inside the reflective housing, the number of diffuse reflections, the reflective housing and reflection, which are performed until the light reaches the measurement unit. The color, shape and material of the connection between the housing and the measuring part, the radiation of the light emitted from the light source, the hole diameters of the entrance and exit, the distance from the entrance to the exit, the entrance and The angle of the facing surface of the exit port with respect to the optical axis, the distance between the incident port and the exit port and the facing surface, etc., and the average reduction rate in this embodiment is at least until each light reaches the measurement unit. It is determined by the absorption of light at the time of the diffused reflection and the number of times of the diffused reflection on the reflecting surface.

In the present disclosure, it is assumed that 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 light emitted is 100%. Further, it may be expressed as a quotient obtained by dividing the amount of light emitted by the amount of emitted light, and further, this quotient may be expressed in logarithmic display. Alternatively, it may be expressed as a number obtained by subtracting a negative sign (“−”) from a logarithmic value obtained by dividing the amount of emitted light by the amount of light emitted (this value is a negative number). Regardless of which method is used, the larger the value, the larger the average decrease rate.

Here, it is considered that the average reduction rate from the same light source to the measuring unit is the same even if the light amount of the light source is different if the wavelength is 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 embodiment, the average reduction rate of each of the plurality of light sources and the plurality of light sources determined by the absorption of light at the time of diffuse reflection on the reflecting surface until each light reaches the measurement unit and the number of times of diffuse reflection. The position of the incident port 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 "certain range" is different depending on the measuring device and is not unconditionally determined, but it depends on the gain adjustment in the measuring unit 30 to be used and the current value of the light source being set by the light amount adjusting unit. It is desirable that the light intensity value of each light is within a range that can be adjusted to a substantially constant value by one or both of the light intensity adjustments of the light source. In this range, for example, the maximum amount of emitted light can be 10 times or less the minimum amount of emitted light. As a result, even if light sources having different light emission amounts are used, the measuring unit can receive a light amount in a certain range suitable for measurement without causing a light amount shortage or conversely light saturation. The amount of light emitted and the amount of emitted light are light amount values represented by values that are indicators of the amount of light, and the measurement method and display method thereof are not particularly limited, but are calculated by, for example, measurement values by an optical spectrum analyzer or optical simulation. It may be a value to be calculated.

<Second aspect>
In the 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. It is provided with a possible light amount adjusting unit.

In the optical measuring device of this embodiment, for example, the amount of emitted light is preliminarily confirmed before adjusting the amount of emitted light of each light source, and the amount of emitted light of each light source is adjusted by the light amount adjusting unit based on the amount of emitted light. It is possible to further suppress variations in the amount of emitted light from the light of each light source.

As for 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. The light emission amount is not particularly limited as long as it can be adjusted. Here, the "narrow range" is different depending on the measuring device and is not unconditionally determined, but for example, the maximum amount of emitted light can be set to 3 times or less of the minimum amount of emitted light.

<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 a light source having a different wavelength, for example, light having a wavelength (referred to as a main wavelength) having a sensitivity characteristic (for example, absorption characteristic) for a certain measurement target is obtained from one light source, and a background value is obtained from another light source. It may be possible to obtain light having a wavelength (referred to as a sub-wavelength) for obtaining the light.

When the amount of light emitted from a plurality of light sources having different wavelengths is different, the position of the incident port corresponding to the plurality of light sources can be set by the configuration of the first aspect, and the amount of emitted light can be kept within a certain range. can.

<Fourth aspect>
In the 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 a wavelength having a sensitivity characteristic for different measurement targets.

In the optical measuring device of this embodiment, at least two types of measurement objects can be measured by the at least two light sources. When the emission amounts of at least two such light sources are different, the position of the incident port corresponding to the plurality of light sources can be set and the emission light amount can be kept within a certain range by the configuration of the first aspect.

<Fifth aspect>
In the fifth aspect of the present disclosure, in addition to the configuration of any one of the first to fourth aspects, the light from the light source having a large amount of light emitted from each of the plurality of incident ports and the exit port is the average. It is installed at a position where the rate of decrease is large.

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 longer the optical path length from the light source to the measurement unit, the greater the number of diffuse reflections. Be done. Therefore, the amount of emitted light can be kept within a certain range by moving the incident port connected to the light source having a large amount of light emission further away from the measuring unit and making the port of incidence connected to the light source having a small amount of light emitted closer. ..

<Sixth aspect>
In the sixth aspect of the present disclosure, in addition to the configuration of the fifth aspect, the light from the light source having a large amount of light emitted from each of the plurality of incident ports and the exit port is due to the reflecting surface up to the measuring unit. It is provided at a position where the diffuse reflection is increased.

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

<Seventh aspect>
A seventh aspect of the present disclosure includes, in addition to the configuration of any one of the first to sixth aspects, a gain adjusting unit for adjusting the amount of light received by the measuring unit, and the certain range is the gain. It is a range of the amount of light that can be adjusted to a substantially constant value for each of the emitted light amounts 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, about 3 times or less. desirable. Within such a range, the gain adjusting unit can adjust the gain of the measuring unit to a substantially constant value, and it is possible to avoid the measurement result from being affected by the difference in the amount of light 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 means that it is a degree.

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

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

For example, when an LED is used as a light source, the amount of light varies depending on the temperature, so it is necessary to provide a temperature control unit such as a temperature control block around the light source. Therefore, there is a portion having a certain thickness between the exit port and the measurement unit, and the measurement unit and the reflective housing are connected to each other via this portion. This part is called a measurement connection part.

The distance (thickness) of the measurement connection portion and particularly its color are factors that increase the reduction rate of light. Since the reflectance of the measurement connection is significantly lower than that of the reflective housing, the number of times of light absorption and diffuse reflection at the measurement connection is the main factor that determines the average reduction rate. sell. Although it depends on the color, material or shape of the measurement connection portion and the reflective housing, for example, the reflectance of the reflective housing is 95%, while the reflectance of the measurement connection portion is 5%. In this embodiment, the average reduction rate is determined by taking into account the number of times of light absorption and diffuse reflection at the time of diffuse reflection on the surface of the measurement connection portion from the outlet to the measurement portion. In this way, the amount of emitted light corresponding to each light source is in a certain range based on the average reduction rate of each of the plurality of light sources and the amount of light emitted from each of the plurality of light sources in consideration of the decrease in the amount of light on the surface of the measurement connection portion. As described above, each incident port is located so as to fit in.

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 reflection housing, the measurement unit, and the shape of each.

<Ninth aspect>
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 of any one of the first to eighth aspects. It has a surface with a larger reduction rate of the amount of light than the reflective surface.

Similar to the measurement connection part described above, there is a portion having a certain thickness between each of the plurality of light sources and the reflective housing, and each of the plurality of light sources and the reflective housing form this portion. They will be contacted via each. This portion is referred to as a light source connection portion.

The distance (thickness) of the light source connection portion and particularly its color are factors that increase the reduction rate of light. Since the reflectance of the light source connection is significantly lower than that of the reflective housing, the number of times of light absorption and diffuse reflection at the light source connection are the main factors that determine the average reduction rate. obtain. Although it depends on the color, material or shape of the light source connection portion and the reflection housing, for example, the reflectance of the reflection housing is 95%, while the reflectance of the light source connection portion is 5%. In this embodiment, the average reduction rate is determined by taking into account the number of times of light absorption and diffuse reflection at the time of diffuse reflection on the surface of the light source connection portion from each of the plurality of light sources to the reflection housing. In this way, the amount of emitted light corresponding to each light source is in a certain range based on the average reduction rate of each of the plurality of light sources including the decrease of the amount of light on the surface of the light source connection portion and the amount of light emitted from each of the plurality of light sources. As described above, each incident port is located so as to fit in.

When the measurement connection unit is further provided between the measurement unit and the exit port, the average reduction rate is determined in consideration of the decrease in the amount of light on the surface of the measurement connection unit.

<10th aspect>
A tenth aspect of the present disclosure is, in addition to the configuration of any one of the first to ninth aspects, the reflective housing includes a perforated surface provided with the plurality of entrance ports and the exit port. It exhibits a box shape including a facing surface facing the perforated surface and a connecting surface connecting the perforated surface and the facing surface.

The box shape referred to in this embodiment is not limited to a rectangular parallelepiped shape, but refers to a shape having an internal space in which front, back, top, bottom, left, and right are drawn by a plane or a curved surface. The plane or 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 enclosure of this embodiment has a perforated surface, a facing surface and a connecting surface as such a flat surface or a curved surface, and in particular, the perforated surface is provided with a plurality of inlets and outlets as such openings. ing. Then, each of the inner surfaces of the perforated surface, the facing surface, and the connecting surface becomes the above-mentioned reflective surface.

Here, the plurality of entrances and exits are provided on a perforated surface which is the same surface. 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 incident port and the optical axis from the exit port to the measuring unit are parallel and opposite to each other. .. That is, the light from the light source enters the inside of the reflection housing at a right angle from the incident port, passes through diffuse reflection inside, and is emitted at a right angle from the exit port to reach the measurement unit. Such a bent optical path is realized by a reflective housing having a simple box-shaped structure without requiring a configuration like an optical fiber.

<11th aspect>
In the eleventh aspect of the present disclosure, in addition to the configuration of the tenth aspect, the portion of the facing surface where the optical axis of the light source having the smallest light emission amount among the plurality of light sources in the reflective housing first abuts is , Inclined toward the outlet.

That is, the optical axis of the light source having the smallest amount of light emitted is incident from the incident port, and the facing surface that first abuts is inclined toward the exit port. In other words, the facing surface faces the exit port. Therefore, the optical axis of the reflected light goes toward the exit port, and reaches the exit port without being reflected too many times in the reflection housing. As a result, the number of diffuse reflections leading up to the measurement unit is reduced, and the average reduction rate is relatively small. Therefore, a light source having the smallest amount of light emission, for example, a light source having an extremely small amount of light as compared with other light sources can be arranged as defined in this embodiment.

<12th aspect>
In the twelfth aspect of the present disclosure, in addition to the configuration of the tenth or eleventh aspect, the optical axis of the light source having the largest light emission amount among the plurality of light sources in the reflection housing is first applied to the facing surface. The contacting portion is perpendicular to the optical axis.

That is, the optical axis of the light source having the largest amount of light emitted is incident from the incident port, and the facing surface that first abuts on the light source is perpendicular to the optical axis. 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 exit port, but goes to the exit port through diffuse reflection in the reflection housing. To reach. Therefore, as compared with the case where only the reflection along the optical axis is directed toward the exit port, the number of diffuse reflections up to the measurement unit is increased, and the average reduction rate is increased. Therefore, a light source having the largest amount of light emission, for example, a light source having an extremely large amount of light as compared with other light sources can be arranged as defined in this embodiment.

<13th aspect>
In the thirteenth aspect of the present disclosure, in addition to the configuration of the twelfth aspect, the distance between the incident port corresponding to the light source having the largest light emission amount and the portion where the optical axis first abuts on the facing surface is the same. The distance between the incident port corresponding to the light source other than the light source and the portion where the optical axis thereof first abuts on the facing surface is shorter than the distance.

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

<14th aspect>
In the fourteenth aspect of the present disclosure, in addition to the configuration of any of the tenth to thirteenth aspects, the portion of the facing surface facing the outlet is parallel to the perforated surface.

In this embodiment, the portion of the facing surface of the reflective housing that faces the exit port is made parallel to the perforated surface so that the light reaches the exit port as vertically as possible, and the measurement is performed from the exit port. It is intended to avoid the decrease due to absorption at the time of diffuse reflection on the inner wall of the portion leading to the portion (for example, the measurement connection portion in the eighth aspect) as much as possible.

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

For example, white is the most suitable 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, for example, a surface having a moderately roughened surface is most suitable. As a material in which diffuse reflection is superior to specular reflection, for example, a synthetic resin such as ABS resin or highly reflective polypropylene resin, which is resistant to ultraviolet deterioration, is suitable.

<Main part of optical measuring device>
The main part of the optical measuring device 10 of the embodiment in the present disclosure is shown in a side sectional view of FIG. The optical measuring device 10 includes a light source 20 that irradiates light downward and a measuring unit 30 that receives light from below. The light source 20 is composed of an LED that irradiates light having a predetermined wavelength. The measuring unit 30 is composed of a photodiode. In the present embodiment, as will be described later, five types of light sources 20 are provided and two types of measuring units 30 are provided. However, since this figure is shown by the I-I cross section shown in FIG. 3, which will be described later, the cross section thereof. Only one of each of the light source 20 and the measuring unit 30 located above is shown.

Below the light source 20, the light source 20 and the reflection housing 40 are connected, and the light source connection portion 52, which is a hole for passing the light emitted from the light source 20, and the measurement unit 30 and the reflection housing 40 are connected for measurement. A temperature control section 50 is provided in which a measurement connection section 51, which is a hole for passing light to the section 30, is bored. The temperature control unit 50 is an aluminum black heating element equipped with a heater and a thermostat, and generates heat when energized. The temperature control unit 50 adjusts the light source 20 to a temperature suitable for a predetermined measurement. Further, the purpose of this temperature adjustment is to prevent fluctuations in the amount of light from the light source, and it is sufficient if the temperature can be adjusted to a certain predetermined temperature. For example, the temperature can be adjusted to a temperature suitable for the reagent used for measurement. The inner space composed of 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 closed space.

For example, when an LED is used as the light source 20, 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 control unit 50 contains a heat source such as a resistance, a certain thickness is generated, and when the temperature control unit 50 is provided between the light source 20 and the reflection housing 40, the temperature control unit 50 has a certain thickness. The temperature control unit requires a light source or a connection unit for connecting the measurement unit and the reflection housing.

In the present embodiment, the reflectance of the light source connection portion 52 and the measurement connection portion 51 is about 5%, which is significantly lower than the reflectance of 95% in the reflection housing 40. 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 in 51 is a main factor for determining the average reduction rate.

Below the temperature control unit 50, a reflective 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 open upper portion is installed. The upper surface of the lid portion 40B is in contact with the lower surface of the temperature control portion 50. The lower surface of the lid portion 40B has a perforated surface 41, and has five inlets 42 (only one is shown in the drawing) and two outlets 43 (only one is shown in the drawing). .) Is formed. The incident port 42 communicates with the light source 20 via the light source connecting unit 52 described above in the temperature control unit 50. The exit port 43 leads to 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 unit 51 and the measurement unit 30.

As the test tool, for example, a holder that can be impregnated with a sample such as a test paper is used. Further, a unit or device formed of a light-transmitting material and having a space capable of accommodating a liquid as a sample may be used as a test tool as a measurement target 80.

The box portion 40A of the reflective housing 40 corresponds to the bottom surface and is a side surface that surrounds the facing surface 44 facing the perforated surface 41 and the periphery of the facing surface 44, and connects the perforated surface 41 and the facing surface 44. It is composed of a contact surface 45 and a contact surface 45. The reflective housing is made of white ABS resin or highly reflective polypropylene resin, which is resistant to deterioration by ultraviolet rays and has high reflectance and positive diffuse reflection, and is a perforated surface in combination with the shape of the facing surface 44 described later. The 41, the facing surface 44, and the connecting surface 45 are all reflective surfaces 46 that reflect the light of the light source 20.

As shown in the bottom perspective view of FIG. 2, the reflective housing 40 is attached to the bottom surface of the temperature control portion 50 by screwing by four attachment portions 40C provided laterally to the box portion 40A. When the screwing of the mounting portion 40C is released and the box portion 40A is removed, 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. Ru. The perforated surface 41 is formed with five inlets 42 and two outlets 43. These five entrance ports 42 are arranged at positions corresponding to the apex of the regular pentagon, the first entrance port 42A is arranged farthest from the exit port 43, and the exit port 43 is slightly located. The second incident port 42B and the third incident port 42C are arranged close to each other, and the fourth incident port 42D and the fifth incident port 42E are arranged closest to the exit port 43. Of the two exit ports 43, the left-hand side of the drawing is the measurement exit port 43A, and the right-hand side of the drawing is the reference exit port 43B.

FIG. 4 schematically shows the positional relationship between the light source 20 and the measuring unit 30 and the incident port 42 and the exit port 43. As described above, the perforated surface 41 as the reflecting surface 46 is formed with five incident ports 42 and two exit ports 43.

A first light source 20A that irradiates light having a wavelength of 810 nm is located at the position of the first incident port 42A. The wavelength of the first light source 20A can be used as a sub-wavelength in the measurement of various items. A second light source 20B that irradiates light having a wavelength of 405 nm is installed at the position of the second incident port 42B. At the position of the third incident port 42C, a third light source 20C that irradiates light having a wavelength of 660 nm is installed. The wavelength of the third light source 20C can be used as the main wavelength in the measurement of creatinine and uric acid. A fourth light source 20D that irradiates light having a wavelength of 610 nm is installed at the position of the fourth incident port 42D. At the position of the fifth incident port 42E, a fifth light source 20E that irradiates light having a wavelength of 556 nm is installed. The wavelength of the fifth light source 20E can be used as the main wavelength in the measurement of calcium. Among these light sources 20, the light emission amount of the first light source 20A is the largest, the light emission amount of the second light source 20B and the third light source 20C is the second largest, and the light emission amount of the fourth light source 20D and the fifth light source 20E is the smallest. .. It should be noted that each of the above wavelengths is merely an example, and a light source 20 that emits light of another wavelength may be installed in any of the incident ports 42.

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

<Transmission of light inside the reflective housing>
The transmission of light inside the reflective housing 40 will be described with reference to the schematic views of FIGS. 5 and 6. The facing surface 44 of the reflective housing 40 as the reflecting surface 46 is a distal parallel surface 44A farthest from the exit port 43 and parallel to the perforated surface 41, and a proximal parallel surface to the perforated surface 41 closest to the exit port 43. 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 plane 44A faces the first incident port 42A. The inclined surface 44B faces the second incident port 42B and the third incident port 42C. The proximal parallel plane 44C faces the exit port 43.

As described above, the first light source 20A having the largest amount of light emission is installed at a position corresponding to the first incident port 42A farthest from the measuring unit 30. The second light source 20B (and the third light source 20C, hereinafter referred to as “the second light source 20B”) having the second largest light emission amount after the first light source 20A is the second light source 42B (and the third light source) closer to the measuring unit 30. It is installed at a position corresponding to the port 42C, hereinafter represented by the “second incident port 42B”). The fourth light source 20D (and the fifth light source 20E, hereinafter represented by the “fourth light source 20D”) having the smallest amount of light emission is the fourth light source 42D (and the fifth light source 42E, hereinafter referred to as the fourth light source 20D) closest to the measuring unit 30. It is installed at a position corresponding to "4th incident port 42D").

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

D1 <D2 <D3 <D4

From the above, the optical axis α1 of the first light source 20A, which is the light source 20 having the largest light emission amount, is perpendicular to the distal parallel surface 44A, which is the first contact portion on the facing surface 44. Further, the distance D1 between the first incident port 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 incident port 42 and the inclined surface 44B.

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

The inclined surface 44B, which is the portion where the optical axis α3 of the fourth light source 20D, which is the light source 20 having the smallest light emission amount, first abuts on the facing surface 44, is also inclined toward the exit port 43.

From the 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 vertically reflected by the distal parallel surface 44A. Here, since the distance D1 from the first incident port 42A to the distal parallel surface 44A is shorter than the distances D2 and D3 between the other incident ports 42 and the inclined surface as described above, the light was emitted from the first light source 20A. The light (including the scattered light β1 from the first light source 20A) has the highest number of diffuse reflections (including the diffuse reflection at the light source connection portion 52, the perforated surface 41 as the reflection surface 46, the communication surface 45, and the measurement connection portion 51). ), The measurement light δ reaches the measurement unit 30. Therefore, the light from the first light source 20A has the largest number of diffuse reflections as a result, and thus the average reduction rate is the largest. If the average reduction rate of the light from the first light source 20A is the largest, the portion where the optical axis α1 of the first light source 20A first abuts on the facing surface 44 is not necessarily perpendicular to the optical axis α1. It does not have to be, for example, the optical axis α2 of the second light source 20B may be a gently inclined surface as compared with the inclined surface 44B which is the first contact portion on the facing surface 44.

Further, the light emitted from the second light source 20B, which is the light source 20 having the next largest light emission amount, with the optical axis α2 becomes the reflected light γ2 reflected in the direction of the exit port 43 on the inclined surface 44B. Here, the distance D2 from the second incident port 42B to the inclined surface 44B is 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 the second highest number of diffuse reflections after the first light source 20A (including diffuse reflection at the light source connection portion 52, the perforated surface 41 as the reflection surface 46, the communication surface 45, and the measurement connection portion 51), and the measured light δ. To the measuring unit 30. 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, so that the average reduction rate is also the second largest 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 becomes the reflected light γ3 reflected in the direction of the exit port 43 on the inclined surface 44B. Here, since the distance D3 from the fourth incident port 42D to the inclined surface 44B is longer than the above-mentioned distances D1 and D2, the light emitted from the fourth light source 20D (including the scattered light β3 from the fourth light source 20D). Passes through the smallest number of diffuse reflections (including the diffuse reflection at the light source connection portion 52, the perforated surface 41 as the reflection surface 46, the communication surface 45, and the measurement connection portion 51), and reaches the measurement unit 30 as the measurement light δ. .. Therefore, the light from the fourth light source 20D has the largest number of diffuse reflections as a result, and thus the average reduction rate is the smallest.

<Functional block>
A functional block diagram of the optical measuring device 10 is shown in FIG. The control unit 60 controls each unit of the optical measuring device 10. The control unit 60 includes a gain adjusting unit 70 that adjusts the gain of light received by the measuring unit 30, a light amount adjusting unit 71 that adjusts the amount of light emitted from the light source 20, and a temperature in the temperature adjusting unit 50, depending on the hardware configuration described later. Functions as a temperature control unit 72 for adjusting the temperature.

The gain adjusting unit 70 may perform correction by multiplying the amount of light actually received by the light source 20 to be used by a predetermined coefficient. If the wavelength is different for each light source, the gain adjusting unit 70 will perform correction for each wavelength as a result. The light amount adjusting unit 71 adjusts the light emission amount by supplying electric power having a predetermined amperage for 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 reflective housing 40 with light having a predetermined wavelength with a predetermined amount of light by the electric power supplied from the light amount adjusting unit 71. The measuring unit 30 receives the light emitted from the reflective housing 40 and irradiated 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 configurations are connected to each other via a bus 69 so as to be communicable with each other.

The CPU 61 is a central arithmetic 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 each of the above configurations and performs various arithmetic processes according to the 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 is composed of 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 embodiment, 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 adjustment unit 70, a light amount adjustment unit 71, and a temperature control unit 72 as shown in FIG. 7 in the optical measuring device 10 by the CPU 31 of the hardware configuration executing the program described above. do.

<Summary of Embodiment>
As described above, in the optical measuring device 10 of the present embodiment, the light source 20 to the measuring unit 30 are the reflection 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. Is covering. In the reflective housing 40, the light source 20 having a large amount of light emitted is kept away from the measuring unit 30, and the light source 20 having a small amount of light emitted is installed near the measuring unit 30. Further, light is diffusely reflected on the inner surface of the reflection surface 46, the light source connection portion 52, and the measurement connection portion 51 on the inner surface of the reflection housing 40.

That is, the light from the plurality of light sources 20 is incident inside the reflection housing 40 via the light source connection unit 52, and further emitted to the measurement unit 30 via the measurement connection unit 51. As a result, from the light source 20 to the measurement unit 30, the amount of light is reduced 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 is a value within a certain range. Optical measurement is performed by irradiating the measuring unit 30 with each of the above-mentioned lights. Therefore, it is cheaper because the box-shaped reflective housing 40 is used instead of the transmission means such as an optical fiber, and since it is a box type, a large space for handling unlike an optical fiber is not required.

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

As a result, the average reduction rate between each light source 20 and the measuring unit 30 is appropriately adjusted, so that the light emitted from the light source having an appropriate amount of light emission, that is, a different amount of light emitted, is appropriate for the measuring unit 30. It is regulated by the amount of light emitted and transmitted.

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

On the contrary, for the light source 20 (for example, the fourth light source 20D or the fifth light source 20E) whose light emission amount is not desired to be reduced 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 an inclined surface 44B inclined to, for example, the measurement unit 30 as described above.

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

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

<Comparison example>
The results when the reflective housing 40 according to the comparative example before adjusting the average reduction rate for each light source 20 is used 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.

For the first light source 20A to the fifth light source 20E in this comparative example, the wavelength (nm), the amount of light emitted (nW), the diameter of the corresponding incident port 42 (unit: mm), and the linear distance between the light source 20 and the measuring unit 30 ( mm), the inclination angle (°) of the facing surface 44 with respect to the optical axis (α1 to α3) passing through the incident port 42, the distance (mm) between the incident port 42 and the facing surface 44, and the distance between the light source 20 and the facing surface 44 (mm). mm) is 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) emitted 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 measuring 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 incident port 42 and the facing surface 44" is 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, it was 11 mm. Further, the difference between the "distance between the measuring unit 30 and the facing surface 44" and the "distance between the exit port 43 and the facing surface 44" is the distance of the measuring connection unit 51, and the value is 9 mm (= 19 mm-10 mm). )Met.

Here, the amount of light emitted from each light source 20 and the amount of emitted light from the measuring unit 30 were measured or calculated as follows. The amount of light emitted was measured by AQ-6315A OPTICAL SPECTRUM ANALYZER (Yokogawa Test & Measurement). The amount of emitted light was calculated by multiplying the amount of light emitted from each light source 20 to the measuring unit 30 obtained by the illumination Simulator CAD ver.1.00.000 (best media). In addition, in the lighting Simulator CAD ver.1.00.000, the simulation was performed using the light source as a point light source, and the calculation was performed assuming that the light source does not absorb light. Further, the reflectance of the reflective housing 40 was 95% (decrease rate was 5%), and the reflectances of the light source connection portion 52 and the measurement connection portion 51 were both 5% (decrease rate was 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 source (second light source 20B to 5 light source 20E, 0.54 nW).

For these light sources 20, the amount of emitted light (pW) in the measuring 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 amount of emitted light in the measuring unit 30 was 0.1450 pW of the first light source, which was 29.59 times that of 0.0049 pW of the second light source 20B, which was the minimum amount of emitted light. The relative ratio of the emitted light amount exceeds 29 times, and is well beyond the range (generally 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. rice field. Further, at this time, none of the emitted light amounts of the first light source 20A to the fifth light source 20E satisfied the amount of light required for measuring the measurement target 80.

By the way, as shown in Table 2 above, the average reduction rate expressed by the common logarithm of the amount of light emitted divided by the amount of emitted light is 5.04 at the maximum of the second light source 20B, and the third light source 20C and the fourth light source 20D. , 5.03 and 4.82, respectively, followed by the first light source 20A and the fifth light source 20E, both of which were the smallest at 4.62. From this result, in the comparative example, no particular relationship was found between the linear distance between the light source 20 and the measuring unit 30 and the average reduction rate.

<Example 1>
Based on the results of the comparative example, we repeated diligent studies so that the amount of emitted light from each light source was within a certain range, and for the first light source 20A to the fifth light source 20E, the wavelength (nm), the amount of light emission (nW), and the corresponding incidents. The diameter of the port 42 (unit: mm), the linear distance (mm) between the light source 20 and the measuring unit 30, the inclination angle (°) of the facing surface 44 with respect to the optical axis (α1 to α3) passing through the incident port 42, and the incident port 42. The distance (mm) between the light source and the facing surface 44 and the distance (mm) between the light source 20 and the facing surface 44 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) emitted 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 measuring 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 incident port 42 and the facing surface 44" is 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, it was 1.8 mm. Further, the difference between the "distance between the measuring unit 30 and the facing surface 44" and the "distance between the exit port 43 and the facing surface 44" is the distance of the measuring connection unit 51, and the value is 10.7 mm (= 20). It was 0.7 mm-10 mm).

At this time, the amount of emitted light for each light source 20 was calculated in the same manner as in the above-mentioned comparative example. The results are shown in Table 4 below.

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

For these light sources 20, the amount of emitted light (pW) in the measuring unit 30 was as shown in Table 4 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 4 above. That is, the maximum amount of emitted light in the measuring unit 30 was 6.760 pW of the second light source 20B, which was 9.67 times the minimum amount of emitted light of 0.699 pW of the third light source 20C. From the above, the relative ratio of the amount of emitted light was 9.67 times, which was within 10 times, and the relative ratio was within a range that could be kept within a substantially constant range by adjusting the amount of light of the light source 20 by adjusting the current value. Further, the amount of emitted light from the first light source 20A to the fifth light source 20E at this time satisfied the amount of light required for measuring the measurement target 80.

Incidentally, as shown in Table 4 above, the average reduction rate obtained in the same manner as in the comparative example is 4.57 for the first light source 20A farthest from the measuring unit 30, and is hereinafter 4. 12. The third light source 20C was 4.00, the fourth light source 20D was 3.85, and the fifth light source 20E was 3.61. The order of the average decrease rate coincided with the order of the linear distance between the light source 20 and the measuring unit 30 (see Table 3).

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

First, as shown in Table 5 above, the adjusted light emission amount is maximum at 25.7 nW for the first light source 20A farthest from the measuring unit 30, 9.2 nW for the second light source 20B farthest next, and then farthest. The third light source 20C was 7.0 nW, the fourth light source 20D distant next was 5.0 nW, and the nearest fifth light source 20E was 2.8 nW, which was the smallest. The maximum light emission amount (first light source 20A, 25.7nW) was 9.17 times the minimum light emission amount (fifth light source 20E, 2.8nW).

For these light sources 20, the amount of emitted light (pW) in the measuring unit 30 is 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 amount of emitted light in the measuring unit 30 is 0.705 pW of the second light source 20B, which is only 1.05 times the minimum amount of emitted light of 0.672 pW of the first light source 20A, and all the light sources 20. It can be said that the amount of emitted light was almost constant. This minute difference in the amount of emitted light is adjusted by ordinary gain adjustment.

The average reduction rate expressed in the same manner as in Table 4 is 4.58 for the first light source 20A farthest from the measuring unit 30, 4.12 for the second light source 20B farthest next, and the third farthest. The light source 20C was 4.00, the fourth light source 20D distant next was 3.85, and the nearest fifth light source 20E was 3.61 which was the smallest. The order of the average reduction rate is in agreement with the order of the linear distance between the light source 20 and the measuring unit 30 (see Table 3), and is also in agreement with the order of the amount of light emitted.

INDUSTRIAL APPLICABILITY The present invention can be used in an optical measuring device in which light from a plurality of types of light sources reaches a measurement unit at one location and measures a measurement target for a plurality of items.

10 Optical measuring device 20 Light source 20A 1st light source 20B 2nd light source 20C 3rd light source 20D 4th light source 20E 5th light source 30 Measuring unit 31 Measuring sensor 32 Reference sensor 40 Reflective housing 40A Box part 40B Lid part 40C Mounting part 41 Perforated surface 42 Incident port 42A 1st incident port 42B 2nd incident port 42C 3rd incident port 42D 4th incident port 42E 5th incident port 43 Exit port 43A Measurement exit port 43B Reference exit port 44 Facing surface 44A Far Position Parallel surface 44B Inclined surface 44C Proximal parallel surface 45 Communication surface 46 Reflection surface 50 Temperature control unit 51 Measurement connection unit 52 Light source connection unit 60 Control unit 61 CPU
62 ROM
63 RAM
64 Storage 69 Bus 70 Gain adjustment unit 71 Light amount adjustment unit 72 Temperature control unit 80 Measurement target α1 to α3 Optical axis β1 to β3 Scattered light γ1 to γ3 Reflected light δ Measurement light

Claims (15)

With multiple light sources that emit at least one different amount,
A measuring unit that measures a measurement target by light emitted from the plurality of light sources, and a measuring unit.
An optical measuring device including a reflective housing in which light emitted from the plurality of light sources is incident and diffusely reflected by an internal reflecting surface is emitted to the measuring unit.
The reflective housing is
A plurality of incident ports that are in contact 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 into the interior from each of the plurality of light sources.
A reflective surface that diffusely reflects light incident from the plurality of incident ports and absorbs a part of the light when diffusely reflected.
It is provided with an outlet that communicates with the measuring unit and emits the diffusely reflected light from the inside to the measuring unit on the reflecting surface.
A light source for each of the plurality of light sources in order to set the amount of emitted light, which is the amount of light emitted from each of the plurality of light sources when reaching the measuring unit via the outlet, to a value within a certain range. Based on the average reduction rate, which represents the rate at which the amount of light emitted from the light emitting amount decreases by the time it reaches the measuring unit, and the amount of light emitted from each of the plurality of light sources, each of the plurality of incident ports is relative to the position of the exit port. Are placed in different positions,
The measuring unit is an optical measuring device that performs optical measurement of the measuring object by irradiating the measuring object with light with the amount of emitted light. The optical measuring device according to claim 1, further comprising a light amount adjusting unit capable of adjusting the light emission amount of each light source so that the emitted light amount corresponding to each light source is contained in a range narrower than a certain range. The optical measuring device according to claim 1 or 2, 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 a wavelength having sensitivity characteristics for different measurement targets. Any of claims 1 to 4, wherein each of the plurality of incident ports and the exit port are provided at positions such that the average reduction rate increases as the light from the light source having a larger light emission amount increases. The optical measuring device according to item 1. 5. The fifth aspect of the present invention, wherein each of the plurality of incident ports and the exit port are provided at positions such that the light from the light source having a large amount of light emission increases the diffuse reflection by the reflecting surface to the measuring unit. The optical measuring device according to. A gain adjusting unit for adjusting the amount of light received by the measuring unit is provided.
The optical measuring device according to any one of claims 1 to 6, wherein the fixed range is a range of light amounts in which each of the received light amounts can be adjusted to a substantially constant value by the gain adjusting unit. .. 1 The optical measuring device according to the section. Any of claims 1 to 8, which is a portion interposed between each of the plurality of light sources and each of the plurality of incident ports and has a surface having a surface having a larger reduction rate of the amount of light than the reflecting surface. The optical measuring device according to item 1. The reflective housing is a communication surface that connects a perforated surface provided with the plurality of incident ports and the exit port, a facing surface facing the perforated surface, and the perforated surface and the facing surface. The optical measuring device according to any one of claims 1 to 9, which has a box shape and the like. The tenth aspect of the present invention, wherein the portion of the reflective housing where the optical axis of the light source having the smallest light emission amount first abuts is inclined toward the exit port. Optical measuring device. 13. The optical measuring device described. The distance between the incident port corresponding to the light source having the largest light emission amount and the portion where the optical axis first abuts on the facing surface is such that the incident port corresponding to a light source different from the light source and its optical axis face each other. 12. The optical measuring device according to claim 12, which is shorter than the distance to the portion of the surface that first abuts. The optical measuring device according to any one of claims 10 to 13, wherein the portion of the facing surface facing the outlet is parallel to the perforated surface. The reflection of light on the reflection surface of the reflection housing is formed of a color, shape or material in which diffuse reflection is superior to specular reflection, or any two or all of them, according to claim 1. The optical measuring apparatus according to any one of claims 14.

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