JPH0577022B2 - - Google Patents

Description

Detailed Description of the Invention (Field of the Invention) The present invention is directed to irradiating a measurement surface of a sample with irradiation light, receiving the reflected light from the measurement surface with a light receiver having an optical sensor, and detecting the measurement surface. The present invention relates to a reflection density measuring device for measuring the reflection density of.

(Prior Art and Technical Background of the Invention) In recent years, it has become possible to quantitatively analyze specific chemical components or formed components contained in a sample liquid such as blood or urine by simply applying small droplets of the sample liquid. Dry-type chemical analysis slides that can be used for
It has been put into practical use.

In order to analyze the chemical components in a sample liquid using such a chemical analysis slide, the sample liquid is dotted onto the chemical analysis slide, and then kept at a constant temperature for a predetermined period of time in an incubator (incubator). ) to cause a coloring reaction (dye-forming reaction), and optically measure the coloring optical density. This chemical analysis slide is irradiated with measuring irradiation light containing a selected wavelength and its reflected optical density is measured, thereby quantitatively analyzing the content of the substance to be measured mainly based on the principle of colorimetry. .

The reflection optical density is measured using a reflection density measuring device. In such a reflection density measuring device, a sample, that is, the chemical analysis slide described above is mounted on the device, the measurement surface of the sample is irradiated with the measurement irradiation light, and the light reflected from the measurement surface is sent to the optical sensor. The reflection density of the measurement surface is measured by receiving the light with a light receiver.

However, when measuring reflection density using such a reflection density measuring device, the mounting accuracy of the sample,
The measurement surface of the sample deviates from the reference position for each measurement due to dimensional accuracy of the sample itself or flexural deformation of the sample. In other words, there is a risk that the measurement surface of the sample may move vertically (perpendicular to the measurement surface) from the reference position.
If such vertical fluctuations of the measurement surface occur, there is a problem in that the positional relationship between the measurement surface and the optical sensor changes, and as a result, the measured concentration changes.

(Object of the Invention) In view of the above-mentioned circumstances, an object of the present invention is to provide a reflection density measuring device in which even if the measurement surface of a sample changes slightly up and down, the fluctuation in the measured density due to the change is extremely small.

(Structure of the Invention) In order to achieve the above object, a reflection density measuring device according to the present invention includes a plurality of light receivers each having a light sensor that receives reflected light from a sample measurement surface.
In at least two of the plurality of light receivers, the distance r from the center of the optical element on the measurement surface side of each light receiver to the optical axis of the irradiation light that irradiates the sample is r ₁ , r ₂ ,
The height h from the center of each optical element to the reference position of the sample measurement surface is h ₁ , h ₂ , the angle θ between each optical element and the sample measurement surface is θ ₁ , θ ₂ , each of the above light receiving When the outputs I of the optical sensors of the receivers are I ₁ and I ₂ , the height h ₁ of one of the receivers is equal to the height r ₁
The output curve showing the variation of the output I ₁ of the optical sensor when h is varied under the combination of and θ ₁ , i.e., r is
The height when the output I ₁ takes the peak value in the output curve showing the relationship between h ₁ and I ₁ when _r 1 and θ are θ ₁
h ₁₀ , and the other photoreceiver is arranged so that its height h ₂ is the output I ₂ of the optical sensor when h is varied under the above combination of r ₂ and θ ₂ It is characterized in that it is arranged so that the output I ₂ in the output curve showing the fluctuation of is higher than the height h ₂₀ when it takes a peak value.

In the reflection density measuring device according to the first aspect of the present invention, the sum value I _t of the optical sensor outputs of the plurality of light receivers is
The reflection density measuring device according to the second aspect of the present invention performs reflection density measurement based on the largest output value I _h of the optical sensor outputs of the plurality of light receivers. be.

In the present invention, if a certain appropriate r and θ are selected, the output curve showing the relationship between h and I under the selected r and θ will normally be a parabolic curve, and at a predetermined h, I will be at a peak value. Based on this fact, at least two light receivers are provided as described above, and one of the two light receivers has a height of
If it is arranged so that h ₁ is lower than the height h ₁₀ when the output peak value is taken, the output peak value will be obtained when the measurement surface is displaced above the reference position, and, The other receiver is at that height.
If it is arranged so that h ₂ is higher than the height h ₂₀ when the output peak value is taken, the output peak value will be obtained when the measurement surface moves below the reference position. It was conceived that the output sum value or the maximum output value of the optical sensors of each of the light receivers does not change much even if the sample measurement surface moves up and down to some extent, and the above configuration is based on this idea.

In addition to cases in which the above-mentioned light receiver consists of only a light sensor, there are cases in which it consists of a light sensor and a lens or optical diaphragm arranged on the measurement surface side of the light sensor.
The optical element on the measurement surface side of the light receiver described above means the light sensor when the light receiver consists only of the above-mentioned optical sensor, and the lens or optical diaphragm when it consists of the above-mentioned optical sensor and a lens or optical diaphragm. do.

(Embodiments) Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a conceptual longitudinal cross-sectional view showing one embodiment of the reflection density measuring device according to the present invention.

The illustrated apparatus includes a sample holder 12 that holds a sample 10, a light source 1414 that emits irradiation light suitable for measuring the reflection density of the measurement surface 10a of the sample, and
an optical fiber 16 that guides the irradiation light emitted from the sample measurement surface 10a and makes it perpendicularly enter the sample measurement surface 10a; a condenser lens 18 that collects the irradiation light emitted from the optical fiber 16; Face 10
The optical receiver includes two optical receivers, namely, a first optical receiver 30a and a second optical receiver 30b, which are optical sensors 301a and 301b such as silicon photodiodes that receive the reflected light reflected from the photodiode a.

In addition, in the illustrated device, the optical fiber 1
6. The condensing lens 18, the sample holder 12 and both optical sensors 301a and 301b are attached to the sample holder 12.
When a sample 10 of regular size is held in a regular state on top, the centers 302a, 302 of both optical sensors are
The height h from b to the reference position of the measurement surface 10a of the sample is h ₁ , h ₂ , the angle θ between the measurement surface 10a of the sample and the optical sensors 301a, 301b is θ ₁ , θ ₂ , They are arranged in a positional relationship such that the distances r from the centers 302a and 302b to the optical axis 22 of the irradiation light are r ₁ and r ₂ , respectively, and further,
h ₁ in the first light receiver 30a is equal to r ₁ and θ ₁
h ₁₀ when the output I ₁ of the optical sensor 301a takes a peak value in the output curve representing the fluctuation of the output I ₁ of the optical sensor 301a when the h is varied under the combination of
_h2 in the _second light receiver 30b is the same as that of the optical sensor 301 when h is varied under the combination of _r2 and _θ2 .
The arrangement is such that Δh ₂ is larger than h ₂₀ when the output I ₂ in the output curve representing the fluctuation of the output I ₂ of b is at its peak value.

That is, in the optical system shown in FIG. 1, if appropriate r and θ are selected, the output curve representing the relationship between h and I under the combination of r and θ will normally be arch-shaped. The curve becomes such that the output I of the optical sensor takes a peak value at a predetermined h. In the above device, r ₁ and θ ₁ and r ₂ and θ ₂ are values that are appropriately selected so that the output curve showing the relationship between h and I becomes an arch-shaped curve, and h ₁ is Output in its arched output curve
such that Δh ₁ is less than h ₁₀ when I ₁ takes its peak value, and h ₂ is the output in its arched output curve.
I ₂ is set to be Δh ₂ larger than the value h ₂₀ when the peak value is taken.

In the device according to the first invention,
Two light receiver optical sensors 3 arranged as described above
01a and 301b are connected to an addition output device 40 as shown in FIG. The device is configured to perform concentration measurements based on _t .

Further, in the device according to the second invention, the optical sensor 30 of the two light receivers arranged as described above
1a and 301b are connected to a comparison selection output device 50 as shown in FIG. The configuration is such that the concentration is measured based on the larger output value I _h .

FIG. 4 shows the outputs I ₁ and _{I 2 of each optical sensor 301a and 301b and the sum value I t (} summing output device 40 FIG. Since both the light receivers 30a and 30b are arranged as described above, the peak value of the output _I1 of the optical sensor 301a is shifted upward by _Δh1 from the reference position S of the measurement surface 10a, as shown by the broken line. The peak value of the output I ₂ of the optical sensor 301b is shifted downward by Δh ₂ from the reference position S of the measurement surface 10a, as shown by the dashed line. As a result, the sum value I _t of these two outputs I ₁ and I ₂ is approximately a distance Δh ₂ below and above the reference position S of the measurement surface 10a of the normally arranged sample, as shown by the solid line. It has a substantially flat portion F that extends by Δh ₁ . Therefore,
According to the first aspect of the present invention, which performs reflection density measurement based on the added value I _t in this way, even if the position of the sample measurement surface 10a moves up and down a little when a sample is actually set, the range of the up-and-down movement can be adjusted. If it is within the above l, I _t hardly changes, so stable reflection density measurement can be performed. Note that, although it is preferable that Δh ₁ and Δh ₂ be equal, they do not necessarily have to be equal.

FIG. 5 is a diagram showing an embodiment of the apparatus according to the second aspect of the present invention. In this case as well, the receiver 3
Since the arrangement of the optical sensors 0a and 30b is the same as that of the first invention as described above, the optical sensors 301a and 30b are
The curves of the outputs I ₁ and I ₂ of 301b are also similar to those of the first invention (FIG. 4) as shown, and the curve of the larger output value I _h is as shown by the solid line in the figure. , is shaped such that the peak value portions of the curves of the outputs I ₁ and I ₂ are located on both sides of the position S of the measurement surface 10a of the normally arranged sample. Therefore, according to the second invention in which the reflection density is measured based on such a larger output value I _h (output value of the comparison selection output device 50), the reflection density is measured based on the output value of one optical sensor. It is possible to perform more stable reflection density measurements than conventional types of measurements. This is because, for example, the output of one optical sensor
When performing measurements based only on I ₂ , when using the peak portion with little output fluctuation, and when the allowable output fluctuation range is ΔI from the peak value to the value at the intersection of the outputs of both sensors, the upper and lower portions of the sample measurement surface 10a The permissible range of vertical movement of the sample measurement surface 10a is 2·Δh ₂ , but when the structure is configured as in the present invention and measurement is performed based on the larger output I, the permissible range of vertical movement of the sample measurement surface 10a for the same permissible output variation range ΔI is 2·Δh 2 . Δh ₁ +2・
This is because the output value I h is approximately twice as large as Δh ₂ , and even if there is a slight vertical fluctuation of the measurement surface, the resulting fluctuation in the output value I _h can be maintained within an extremely small range. In this case as well, it is preferable to set Δh ₁ =Δh ₂ , but it is not necessary to do so, as in the case of the first invention.

Note that r ₁ and θ ₁ and r ₂ in both of the above embodiments
and θ ₂ have an arch-like output curve representing the relationship between h ₁ and I ₂ and h ₂ and I ₂ under these combinations, but in the present invention, r ₁ and θ ₁ and
r ₂ and θ ₂ may be such that the above output curve under their combination has a peak value, in other words, a curve having an inflection point, and does not necessarily form an arch-shaped curve. Not limited to cases.

6 and 7 are schematic vertical cross-sectional views (corresponding to FIG. 1) showing other embodiments of the reflection density measuring apparatus according to the first and second aspects of the present invention. In these drawings, elements having the same functions as those in the embodiment shown in FIG. 1 are denoted by the same reference numerals, and explanations thereof will be omitted. The embodiment shown in FIG.
0b is the optical sensor 301a, 301b and the lenses 303a, 303b arranged on the measurement surface side of the optical sensor.
It is composed of: In this embodiment, the angles θ between the measurement surface 10a of the sample and the lenses 303a and 303b are θ ₁ and θ ₂ , and the distance r from the centers 304a and 304b of the lenses 303a and 303b to the optical axis 22 of the irradiation light is r ₁ , r ₂ , and further, under the combinations of r ₁ and θ ₁ and r ₂ and θ ₂ , from the centers 304a and 304b of the lens 24 to the measurement surface 10a
Similarly to the case shown in FIG _{. 1, the heights h 1 and h 2 up to} the height of It is configured as follows. Further, in the embodiment shown in FIG. 7, the light receivers 30a and 30b are constituted by optical sensors 301a and 301b and optical diaphragms 306a and 306b provided with apertures 305a and 305b arranged on the measurement surface side of the optical sensors. ing. In this embodiment, the angles θ between the measurement surface 10a of the sample and the apertures 306a, 306b are θ ₁ , θ ₂ , and the centers of the apertures (aperture centers) 307a, 307
The distance r from b to the optical axis 22 of the irradiated light is set to be r ₁ and r ₂ , and further, under the combinations of r ₁ and θ ₁ and r ₂ and θ ₂ , the centers of the aperture 307 a and 307
As _in the _{case shown in FIG} . Set it to be greater than ₂₀ .

In these embodiments, the heights h ₁ and h ₂ from the center of the lens or the center of the diaphragm to the measurement surface are also
are set smaller than the height h ₁₀ and larger than h ₂₀ at which the sensor outputs I ₁ and I ₂ take their peak values, so the outputs I ₁ , I ₂ and both outputs I ₁ , I The added value I _t of ₂ or the larger output value I _h is the same as in FIGS. 4 and 5 described above.

In the above embodiment, the number of light receivers is two, but it is also possible to have three or more light receivers, in which case at least two light receivers must be positioned so as to satisfy the above conditions. It is fine as long as it has been done. In this case, for example, in a device having three light receivers, it is desirable that the other one is arranged so that its output peak value is located at the reference position on the measurement surface.

The reflection density measurement position according to the present invention can be changed in various ways without departing from the gist thereof, and is not limited to the above-mentioned embodiments.

(Effects of the Invention) As described above, the reflection density measuring device according to the present invention includes at least two light receivers, and these light receivers have heights h ₁ and h ₂ of their outputs I Height h ₁₀ when ₁ and I ₂ take their peak values
The reflection is based on the sum I t of the outputs I ₁ and _{I 2 of} both receivers arranged in this way, or the larger output value _{I h .} Since it is configured to perform concentration measurements,
For example, even if the above h changes for each measurement due to the sample holding accuracy of the sample holder or the dimensional accuracy of the sample itself, or if the above h changes due to the sample itself bending during long-term measurement, the h
The changes in I _t and I _h due to changes in is very small, and therefore extremely stable reflection density measurement is possible.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional conceptual diagram showing one embodiment of the apparatus according to the first and second inventions, FIG. 2 is a block diagram showing a part of one embodiment of the apparatus according to the first invention, FIG. 3 is a block diagram showing a part of an embodiment of the device according to the second invention, FIG. 4 is a diagram showing an example of the relationship between each output in FIG. 2, and FIG. FIGS. 6 and 7 are diagrams illustrating an example of the relationship between the respective outputs, and similarly to FIG. 1, they are longitudinal cross-sectional conceptual diagrams showing an embodiment of the apparatus according to the first and second aspects of the present invention, respectively. 10...Sample, 10a...Sample measurement surface, 14...
...Light source, 30a, 30b... Light receiver, 301a,
301b... optical sensor, 302a, 302b, 3
04a, 304b, 307a, 307b... Centers of optical elements on the measurement surface side of the light receiver.

Claims (1)

[Claims] 1. Reflection in which a measurement surface of a sample is irradiated with irradiation light, and the reflected light reflected from the measurement surface is received by a plurality of light receivers having optical sensors to measure the reflection density of the measurement surface. In the concentration measuring device, the distance r from the center of the optical element on the measurement surface side of each light receiver in at least two of the plurality of light receivers to the optical axis of the irradiation light is r ₁ , r ₂ , and each of the above The height h from the center of the optical element to the reference position of the measurement surface is h ₁ , h ₂ , the angle θ between each optical element and the measurement surface is θ ₁ , θ ₂ , the light of each of the light receivers is When the output I of the sensor is I ₁ and I ₂ , the above height h ₁ of one photoreceptor is equal to the above distance
The height h 10 when the output I ₁ of the optical sensor reaches its peak value in the output curve representing the variation of the output _{I 1} of the optical sensor when the height h is varied under the combination of r ₁ and angle θ ₁ and the other receiver is arranged such that its height h ₂ is equal to the distance r ₂ and the angle θ ₁
so that the height h ₂₀ is higher than the height h ₂₀ when the output I 2 takes a peak value in the output curve representing the variation of the output I ₂ of the optical sensor when the height h is varied in combination with 1. A reflection density measuring device, characterized in that the reflection density measurement device is configured to measure the reflection density based on an added value I _t of optical sensor outputs of the plurality of light receivers. 2. The reflection density measuring device according to claim 1, wherein the light receiver comprises only an optical sensor. 3. The reflection density measuring device according to claim 1, wherein the light receiver comprises an optical sensor and a lens disposed on the measurement surface side of the optical sensor. 4. The reflection density measuring device according to claim 1, wherein the light receiver comprises an optical sensor and an optical aperture disposed on the measurement surface side of the optical sensor. 5. In a reflection measurement device that measures the reflection density of the measurement surface by irradiating the measurement surface of the sample with irradiation light and receiving the reflected light reflected from the measurement surface with a plurality of light receivers each having an optical sensor, the above-mentioned In at least two of the plurality of light receivers, the distance r from the center of the optical element on the measurement surface side of each light receiver to the optical axis of the irradiated light is r ₁ , r ₂ , and the distance r from the center of each optical element to the above The height h of the measurement surface to the reference position is h ₁ , h ₂ , the angle θ between each optical element and the measurement surface is θ ₁ , θ ₂ , and the output I of the optical sensor of each light receiver is I ₁ , I ₂ , one receiver has the above height h ₁ and the above distance
The height h 10 when the output I ₁ of the optical sensor reaches its peak value in the output curve representing the variation of the output _{I 1} of the optical sensor when the height h is varied under the combination of r ₁ and angle θ ₁ The other receiver is placed so that its height h ₂ is lower than the distance
The height h ₂₀ when the output I 2 of the optical sensor takes a peak value in the output curve representing the fluctuation of the output I ₂ of the optical sensor when the height h is varied under the combination of r ₂ and angle _{θ 1} , and is configured such that the reflection density is measured based on the largest output value I _h of the optical sensor outputs of the plurality of light receivers. Reflection density measuring device. 6. The reflection density measuring device according to claim 5, wherein the light receiver comprises only an optical sensor. 7. The reflection density measuring device according to claim 5, wherein the light receiver comprises an optical sensor and a lens disposed on the measurement surface side of the optical sensor. 8. The reflection density measuring device according to claim 5, wherein the light receiver comprises an optical sensor and an optical aperture disposed on the measurement surface side of the optical sensor.