JP2004163401A - Detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact apparatus enabling measurement online. <P>SOLUTION: In the measurement apparatus including, near an object whose light transmission characteristics are determined, a light source for irradiating at least a first part of the surface of the object with a light, a screen device for screening at least a second part of the surface from the light, and a light-receiving part for receiving the light transmitted through the object and emitted from at least a part of the second part of the surface, the second part is at least partly contiguous with the first part, and the whole second part is preferably enclosed by the first part. As an efficient embodiment, the screen device is movable relative to at least the light-receiving part. The measurement device is very much suitable for use, in a sorting apparatus for selecting and sorting the plurality of successive objects, for example fruits, according to the light transmission characteristics. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The invention relates to a measuring device according to the preamble of claim 1.
[0002]
[Prior art]
As such a device, one disclosed in US Pat. No. 5,089,701 is known. This device transmits light in the near-infrared wavelength region and acquires its transmission spectrum, for example, in order to nondestructively measure the sugar content of fruits. The entrance and exit positions on the surface of the fruit to accurately measure how much light enters the fruit and then exits from a given point, while ensuring a sufficiently long transmission path A tubular light guide nozzle. Further, a minimum necessary distance is selected as an interval between the incident position and the output position.
[0003]
As a similar measuring device, Kawano et al. "Determination of Sugar Content in Intact Peaches by NIR Spectroscopy with Fiber Optics in Interaction Mode" (described in J. Japan. Has been. This device utilizes an optical fiber having an output fiber portion located at the center when viewed in cross section, and an annular input fiber portion surrounding the periphery thereof. The optical fiber guides light rays to the fruit upon incidence and guides light rays from the fruit upon exit.
[0004]
The two devices described above are obviously not suitable for online measurements, i.e. measurements made while the fruit is moving on the sorter. On-line measurements impose stringent requirements on the performance of the detector, especially the overall performance of speed, accuracy and repeatability.
[0005]
U.S. Pat. No. 5,089,701 describes selecting an intermediate distance that can achieve a sufficiently large optical path, with the two positions being restricted as described above. Kawano et al. , Offers a very compact configuration suitable for desk measurements. In this device, not only the transmitted light due to the transmitted light, but also the reflected light arrives at the emission section. It has been found that this reflected light indicates information completely different from the information to be obtained by transmission.
[0006]
[Means for Solving the Problems]
In order to overcome the disadvantages as described above, the present invention provides a measuring device characterized in that the second part is at least partially in contact with the first part.
[0007]
Thereby, an excellent effect of realizing a compact configuration can be obtained, and the reflected light can be blocked.
[0008]
As a further embodiment, the device is characterized in that the entire second part described above is surrounded by a first part.
[0009]
With such an arrangement, it is possible to obtain an excellent effect that the intensity of incident light can be adjusted and set repeatedly for various fruits.
[0010]
As still another embodiment, the measuring device according to the present invention is characterized in that at least the screen device and the light receiving unit are housed in one holder. In particular, the screen device is movable at least with respect to the light receiving unit, and further, the screen device includes a shielding cap arranged on a cylindrical holder. More specifically, the light source is arranged on the holder and is arranged at a fixed position with respect to the light receiving section.
[0011]
In addition, the present invention comprises a classification device for selecting and classifying a plurality of consecutive objects, for example fruits, according to the light transmission characteristics, the classification device comprising a measuring device having any of the features described above. It is characterized by the following.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Embodiments of the present invention will be described in detail with reference to the following drawings.
FIG. 1 is a diagram showing an outline of the present invention.
FIG. 2 is a perspective view showing a specific embodiment of the present invention.
1 and 2, the same members are denoted by the same reference numerals.
[0013]
FIG. 1 shows a cross-sectional view of the object P. Here, the object, that is, the agricultural product P indicates, for example, a fruit, specifically, an apple. The object P is irradiated with light from the light source 10. In particular, light is applied to a portion of the object P where light from the light source 10 is not blocked by the screen 11. FIG. 1 shows a state in which the screen 11 is not in contact with the object P and is located at a position slightly away from the object P. Depending on the measurement situation, it is possible to select a non-contact type measurement form as shown or another measurement form, ie a contact type measurement form as described above. In order to measure the sugar content contained in the fruit, the light source 10 emits light in a wavelength region of 300 nm to 1500 nm. Further, if necessary, a fluctuating optical signal, for example, pulsed light can be used.
[0014]
As shown in FIG. 1, in this configuration, the first part 1 of the fruit surface is illuminated, and light permeates the object P at the first part 1. In FIG. 1, a second part 2 is formed on the fruit surface between S1 and S2. The second part 2 is entirely shielded from the light source 10. To illustrate such a configuration, the ends of the non-illuminated part 2, i.e. the two rays 11 and 12 defining the boundary, are shown schematically in FIG. In other words, the shielding area S1S2 is obtained as a result of the arrangement of the screen 11 with respect to the light source 10. The first part 1 located outside the area S1S2 on the fruit surface is partially or entirely illuminated according to the configuration of the light source 10. Light that has entered the object P through the first part 1 may be emitted from the second part 2 depending on the optical characteristics of the object. The emitted light is thereafter received by the light receiving unit 12. A detailed description of the subsequent light guiding and processing will not be given, but it will be apparent to those skilled in the art that the optical fiber can be effectively used and the computer processes the optical signal to determine, for example, the transmission characteristics of the object. Execute
[0015]
FIG. 2 is a perspective view of a specific embodiment of the above-described configuration. More specifically, an object P, for example an apple, is placed on an hourglass-shaped roller 30 attached to a classifier (not shown) known to those skilled in the art. The classification device is configured such that the roller 30 rotates around the axis of cylindrical symmetry indicated by the arrow r, and the object P also rotates accordingly. Generally, the object to be measured passes through the detection unit along the transport direction indicated by the arrow T. In such a detection unit, the measurement head 20 is positioned near or in contact with the measurement or measurement object.
[0016]
In the embodiment shown in FIG. 2, the measuring head 20 is a holder that holds both the light source 10 and the screen 11. More specifically, a plurality of light sources 10 ₁ , 10 ₂ ,... These are, for example, a plurality of light emitting diodes LED or a halogen light source, which irradiates a light beam appropriately focused to obtain a sufficient light intensity. The measuring head 20 is connected to the above-described main body of the detection unit by the coupling unit 14, and transmission of all signals is performed through the coupling unit. Further, the coupling section 14 accommodates a positioning mechanism, that is, means for moving the measuring head 20 toward the object and separating the measuring head 20 from the object.
[0017]
On the opposite side of the annular holder 13, a tube 15 in which the light receiving unit 12 is disposed is disposed. In the present embodiment, an optical fiber is used as the light receiving section. The light receiving unit is guided and connected within the coupling unit 14. Closed to the end of the optical fiber in the tube 15 is a closure cap 17, forming a tube end 16. This tube end 16 is designed so that the light that reaches it reaches the end of the optical fiber in as good a condition as possible and then is processed as a signal. For example, multiple reflective surfaces with appropriate curvature and mirror properties are used. Alternatively, a lens system composed of one or more lenses, or a combination of these is used. At the end of the tube, an optimal plastic flap-like screen 11 is arranged so as to fit the shape of the object and obtain a suitable shielding effect.
[0018]
As a modification of the present embodiment, a metal cap having an appropriate size or, if possible, a variable size can be used. The metal cap is not flexible, but can be placed near or in contact with the fruit to provide a heat resistant effect on the light source lamp. FIG. 2 also shows the first part 1 and the second part 2 of the surface of the object P. The illuminated first part 1 is hatched. Furthermore, the screen 11 is held in contact with the object or at a position slightly away from the object, depending on the curvature of the object and the arrangement of the light sources 10 ₁ and 10 ₂ .
[0019]
In the classification device, in order to obtain a measurement result with a small error, several measurement heads 20 may be arranged side by side in the front-rear direction, and the same fruit may be measured several times. At this time, since the roller is rotating, the detector is positioned at a different part of the fruit for each measurement. Furthermore, it is also possible to arrange the units by arranging the rows of measuring heads as described above in parallel, and to measure the rows of objects passing side by side on the same conveyor.
[0020]
As another embodiment (not shown), a configuration in which only the screen 11 designed as a tube can be moved can be selected. It is desirable to use a telescopic telescopic operation for this movement. This, in contrast, eliminates the need to move the optical components, ie, the light source and the optical fiber. Thus, abrasion, changes in relative arrangement, and breakage of wires and / or fibers can be effectively avoided.
[0021]
Further, the detector comprises a member fixed in position with respect to the classifier. In many cases, this is a mounting frame fixedly connected to the sorting device.
[0022]
As is clear from the above description, the measuring head is designed to be compact, so that it has an excellent advantage that it can be applied to various types of classification devices. Furthermore, this makes it possible to automatically and speedily perform online measurement.
[0023]
As will be apparent to those skilled in the art, other configurations can be employed for the components, particularly for the light source, light guiding and light focusing. Further, the processing of the acquired signal, in particular, a method for determining the characteristics of the object, and how the determination result is reflected in the selection of the object and the operation of the discharging or sending means of the object is performed in the art. It is well known. Further, some modifications in the above-described embodiment are also included in the scope of the above-described claims.
[Brief description of the drawings]
FIG. 1 is a diagram showing an outline of the present invention.
FIG. 2 is a perspective view showing a specific embodiment of the present invention.

Claims (10)

In the vicinity of the object whose light transmission characteristics are to be determined,
A light source illuminating at least a first part of the surface of the object with a light beam,
A screen device for shielding at least the second part of the surface from the light beam,
A light-receiving unit that transmits the object and receives light emitted from at least a portion of the second part of the surface,
The said 2nd part is a measuring device characterized by being at least partially adjacent to the said 1st part. The measuring device according to claim 1,
The said 2nd part is the measuring device characterized by the whole being surrounded by the said 1st part. In the measuring device according to claim 1 or 2,
At least the screen device and the light receiving unit are housed in one holder. The measuring device according to claim 3,
The measuring device, wherein the screen device is movable with respect to at least a light receiving unit. In the measuring device according to claim 3 or 4,
The said screen apparatus is comprised from the shielding cap arrange | positioned at the cylindrical holder, The measuring device characterized by the above-mentioned. The measuring device according to any one of claims 3 to 5,
The measurement device according to claim 1, wherein the light source is disposed on the holder, and is disposed at a fixed position with respect to the light receiving unit. The measuring device according to any one of claims 1 to 6,
A measuring device having a fixed position with respect to a classification device for classifying the object to be inspected, that is, an agricultural product. The measuring device according to claim 7,
The measuring device is formed as a part of a mounting frame. The measuring device according to any one of claims 1 to 8,
A measuring device, wherein the light source emits light having a wavelength range of 300 nm to 1500 nm. In a classification device that selects a plurality of continuous objects, for example, fruits according to light transmission characteristics, and classifies them,
A classification device comprising the measurement device according to claim 1.

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