JPH08201273A - Optical-source device of near-infrared-component analyzer - Google Patents

Abstract

PURPOSE: To simplify the assembling constitution of the optical-source device of a near-infrared-component analyzer by providing many through holes in a block in the array pattern, coupling a filter, which transmits the wavelength different from that of a light emitting diode, into each through hole, and further inserting an O-ring between the filter and the light emitting diode. CONSTITUTION: Many through holes 4a are provided in a block 4 in the array pattern. For the through hole 4a, a small diameter part 4b corresponding to a small-diameter light emitting part 9a of a light emitting diode 9 to be inserted and a large-diameter part 4c corresponding to the diameter 11 to be inserted are provided. Furthermore, an O-ring 50 is provided at the shoulder part between the small-diameter part 4b and the large-diameter part 4c of the through hole 4a, and the shock interference of the filter 11 and the light emitting part 9a of the light emitting diode 9 is absorbed. Thus, the breakdown of the parts is prevented. A Fresnel lens 12 for condensing light is stuck to the surface of the through hole 4a, and the come-off of the filter 11 is prevented. The bottom part of the light emitting diode 9, which is exposed in the recess part 4d provided at the rear part of the block 4, is supported by an array supporting plate 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a near infrared component analyzer for quantitatively analyzing chemical components contained in cereals and the like.

[0002]

2. Description of the Related Art Near-infrared component analyzers measure the contents of various components such as proteins, starches, amylose and fatty acids contained in cereals, etc. A near infrared light flux having Near-infrared light fluxes having different wavelengths are emitted from a large number of light sources toward one point in the sample. Therefore, each near-infrared light flux forms an angle with each other, and the near-infrared light flux incident on one point in the sample passes through different points of the sample and reaches the detector. Since the sample did not pass under the same conditions, accurate component analysis results cannot be obtained. The present applicant has filed a patent application for a near-infrared component analyzer that performs measurement by passing each near-infrared light flux through a sample under the same conditions.
176766 and Japanese Patent Application No. 6-162202. The present invention intends to provide the light source device of the near-infrared component analyzer with a new and useful configuration.

[0003]

The near infrared light having these wavelengths is usually obtained by a light emitting diode. In order to obtain near-infrared light having a different wavelength from each light emitting diode, a light ray from the light emitting diode is obtained through a filter, and the transmission wavelength of the filter is made different. The number of light emitting diodes arranged in an array is usually 10 or more, and the assembly work is complicated because filters having different filtering wavelengths are provided for these. A first object of the present invention is to provide a light source device for a near infrared component analyzer, which simplifies the assembly of a light emitting diode and a filter. Another object of the present invention is to provide a light source device for a near infrared component analyzer which can be assembled without damaging the light emitting surface of the light emitting diode and the filter.

[0004]

In order to achieve the above object, according to the present invention, the near-infrared light from a plurality of light sources emitting near-infrared light at different wavelengths is condensed to substantially the same point. The light source of the near-infrared component analyzer is designed to be condensed by the diffusing means and then diffused by the diffusing means, and the diffused light thus obtained is guided to the detector through the sample holding portion holding the sample to be analyzed and converted into an electric signal. In the device, the light source device is composed of an array of light emitting diodes serving as a plurality of light sources, and each light emitting diode is fitted into an opening provided in the block with its light emitting surface facing the condensing lens side. A light source device for a near-infrared component analyzer is provided, in which a filter is fitted so as to cover the light emitting surface via an O-ring.

[0005]

Since the light emitting diode and the filter are fitted into the large number of openings provided in the block, the assembly becomes very easy. Further, since the filter is arranged on the light emitting surface of the light emitting diode via the elastic O-ring, the filter and the light emitting surface of the light emitting diode do not come into contact with each other, and there is no fear of damage to each other. Further, since the light emitted from the light emitting surface is shielded by the O-ring, there is no risk of light leakage.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the accompanying drawings. In FIG. 1, a cylindrical body 3 is attached to an upright frame 2 installed on a base 1, and extends from the vertical frame 2 in the horizontal direction. A light source device LS and an optical system are provided in the cylindrical body 3. In the light source device LS, a block 4 is provided at the left end portion of the tubular body 3 with its front face toward the right end portion, that is, toward the upright frame 2 side, and the light emitting diodes fitted into a large number of through holes 4 a provided in the block 4 respectively. Have 9. The light emitting surface portion 9a of the light emitting diode 9 has a body portion 9b.
Since the diameter is smaller, the through hole 4a is also formed as a small diameter portion 4b near the front surface of the block 4, and then the diameter is expanded, and the expanded diameter portion 4c is fitted with the filters 11 each having its own transmission wavelength. . A large-diameter recess 4d is provided on the rear surface of the block 4, and the bottom of the light-emitting diode 9 exposed in the recess 4d is held by the array support plate 10. Further, behind the array support plate 10, a circuit board 14 for driving and controlling the light emitting diodes 9 is provided, and the panel 4 closes the recess 4d. The rear part of the cylinder 3 is closed by a lid 7. It is preferable that the block 4 and the panel 5 be made of a material having a good heat transfer such as metal so as to have a function of a heat sink that absorbs the heat generated from the light emitting diode 9 and transfers the heat to the cylindrical body 3.

The near infrared light emitted from the light emitting diode 9 and passing through the filter is supported by the Fresnel lens 12 attached to the front of the block 4 at the right end of the cylindrical body 3.
The light is focused on one point in the bore 16a penetrating the hole 6. The near-infrared light focused at one point is the three semi-transparent plates 1 fitted in the bore 16a of the support 16 provided immediately after the focusing point.
It is diffused by 7, 18, and 19. The intensity of the diffused light is maximum in the horizontal direction along the optical axis L as a whole. With reference to FIG. 2, a vertical movement member 23 provided inside the upright frame 2
Is screwed with the two screw rods 21 and 22. The screw rods 21 and 22 are the bearings 25 and 27 provided on the base 1 and the bearings 24 and 27 provided on the sample container holding portion 2a on the top of the upright frame 2.
26 is rotatably held by the motor 26 and is rotated in synchronization with each other by a motor 28 mounted on the base 1 via gears 21a and 21b fitted to the lower end inside the base 1. That is, by rotating the screw rods 21 and 22, the sample container 30 inserted from the sample container holding portion 2a and arranged on the vertical movement member 23 can be moved up and down. Further, the thermistor element 31 is provided on the upper surface of the vertical movement member 23.
When the sample container 30 is placed, the thermistor 31 is inserted into one of the through holes 32 provided on both sides of the bottom of the sample container 30. Measure the sample temperature of.

As is clear from FIG. 2, the through hole 32
Are symmetrically provided on the bottom of the sample container 30,
Even if the sample container 30 is inserted into the container holding portion 2a in the wrong direction, the thermistor 31 can be introduced into the sample container 30 through any of the through holes 32. The front wall 2f and the rear wall 2r of the upright frame 2 are provided with circular openings that are aligned with the tubular body 3, and the rear wall 2r has an opening 2b at the end of the three translucent bodies 17, 18, and 19 The part 19 is fitted, and the transparent glass 34 is fitted in the opening of the front wall 2f. Further, a rectangular concave portion 35 is formed on the rear surface side of the front wall 2f, and a sliding member 36 is provided in the concave portion 35. The sliding member 36 moves up and down in the concave portion 35 in cooperation with the above-mentioned vertical moving member 23 to move the vertical moving member 23. Is opened, the opening of the rear surface wall 2f is closed, and conversely, when the vertical movement member 23 is lowered, the opening of the rear surface wall 2r is opened. When the up-and-down moving member 23 descends, the sample container 30 placed on the up-and-down moving member 23 aligns with the opening, emits from the light source 9, and is translucent plate 17, 18, 19.
The near-infrared light that has become diffuse light through the sample is transmitted through the sample in the sample container 30, and further passes through the transparent glass 34 of the opening provided in the front wall 2f of the upright frame 2 to be aligned with the transparent glass 34, The light is incident on an optical detector 42 attached to a transparent plate 38 that covers the recess 35.

An opening is provided in the sliding member 36, and an optical standard filter 37 is fitted in this opening. The optical standard filter 37 covers the transparent glass 34 when the sliding member 36 moves up in association with the vertical movement member 35, so that the diffused light is the optical standard filter 37.
To reach the photodetector 42. Detector 42
Is covered with a cover 39 attached to the transparent plate 38 together with the arithmetic processing circuit 43 provided immediately after. The operation of the near infrared component analyzer of this embodiment will be described below. The sample container 30 placed on the vertical movement member 23 through the sample container holding part
When the motor 28 is driven to lower the vertical movement member 23 to the position 23 'shown by the broken line in FIG. 2, the diffused light is spread along the optical axis L to the sample inside the sample container 30 as described above. Reach the detector 42 after passing through. Vertical movement member 23
Can be lowered stepwise by controlling the rotation of the motor 28, diffused light can irradiate each part in the vertical direction of the sample, each part of the sample can be measured, and if a measurement average is taken, The reliability of sample component measurement can be improved.

Since the diffused light includes those having different wavelengths obtained by passing the near infrared light from the light emitting diode 9 through the filter 11, the near infrared light having each wavelength is in the sample. Since it is absorbed by the corresponding components, it is possible to analyze the components of the sample with considerable accuracy by examining the absorption of near infrared light at each wavelength. After measuring the components of the sample, when the motor 28 is rotated in the reverse direction to raise the vertical movement member 23, the sliding member 36 is raised in conjunction with this and the optical standard filter 37 covers the transparent glass 38. Is the standard filter 3
After passing through 7, the light intensity is reduced and reaches the optical detector 42. Therefore, the detector 42 is protected from strong light, and the standard filter 37 enables optical calibration at the time of measurement.

Now, referring to FIGS. 3 and 4, the light source device LS is enlarged and shown in detail, in which the block 4 is provided with twelve light emitting diodes 9 whose bottoms are fixed by the array support plate 10. The small-diameter light emitting surface portion 9a is fitted in the through hole 4a, and is fitted in the opening-side small-diameter portion 4b.
The through hole 4a is provided with an enlarged diameter portion 4c adjacent to the small diameter portion 4a, and an O-ring 50 is attached to a shoulder portion defined between the small diameter portion 4b and the enlarged diameter portion 4c. Also, the expanded portion 4
As described above, the filter 11 is fitted in c, and the light emitting surface 9a of the light emitting diode 9 and the filter 11 are inserted.
Are combined via an O-ring 50. Further, the filter 11 is prevented from coming off by a Fresnel lens 12 provided on the surface of the block 4.

[0012]

EFFECT OF THE INVENTION Light emitting diode 9 and filter 1
1 into the through hole 4a of the block 4 and the Fresnel lens 1
The light source device LS can be easily assembled because it is only pressed by 2. Since the light emitting surface 9a of the light emitting diode 9 and the filter 11 are combined via the O-ring 50, the O-ring 50 serves as a buffer member for each other and damage is prevented. Further, the O-ring 50 is a light emitting diode 9
Since it surrounds the light emitting surface portion 9a, it is possible to block light that goes to the side and prevent leakage of light.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is an enlarged detailed sectional view of the light source device shown in FIG.

FIG. 4 is a front view of the light source device.

[Explanation of symbols]

 4 Blocks 4a Through Holes 9 Light Emitting Diodes 10 Array Support Plates 11 Filters 12 Condensing Lenses 17, 18, 19 Semi-Transparent Plates 23 Vertical Moving Members 28 Motors 31 Thermistor Elements 30 Sample Containers 36 Sliding Members 37 Optical Standard Plates 42 Detectors 43 arithmetic processing circuit 50 O-ring L optical axis LS light source device

Claims (3)

[Claims] 1. Near-infrared light from a plurality of light sources each emitting near-infrared light at different wavelengths is condensed at a substantially same point by a condenser lens and then diffused by a diffusing means, thus obtained. In the light source device of the near-infrared component analyzer, which is configured to guide the diffused light to a detector through a sample holding unit that holds a sample to be analyzed and convert it into an electric signal, the light source device is a light source that becomes the plurality of light sources Each light emitting diode is composed of an array of diodes, and each light emitting diode is fitted into an opening provided in the block with its light emitting surface facing the condenser lens side, and a filter is inserted into the opening through the light emitting surface through an O-ring. A light source device for a near-infrared component analyzer, which is fitted so as to cover it. 2. The light source device for a near-infrared component analyzer according to claim 1, wherein the condenser lens is superposed on the block to close the opening. Light source device. 3. The light source device for the near-infrared component analyzer according to claim 2, wherein the condenser lens is a Fresnel lens.