JP2007024651A - Non-destructive sugar content meter, and non-destructive sugar content measuring method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a non-destructive sugar content meter and a non-destructive sugar content measuring method, capable of measuring precisely sugar content of the overall measured object, without affecting the measured object. <P>SOLUTION: This meter/method has a mounting block 11 for mounting the measured object 1. A rotating means 12 rotates a light source 13 relative to the measured object 1 on the mounting block 11, in the periphery thereof. The light source 13 emits near-infrared ray to the measured object 1, while rotated relative to the measured object 1 by the rotating means 12. Irradiation energy of the light source 13 is changed therein for the emission to find the sugar content ranging over from in the vicinity of a surface of the measured object 1, up to the center thereof. A transmitted light of the near-infrared beam, transmitted through the measured object 1, is received by a light-receiving part of a photoelectric conversion part 14. The sugar content of the measured object 1 is found by a calculation means of a control computation part 16, based on the absorbance of a specified wavelength of the transmitted light received by the light-receiving part. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a non-destructive sugar content meter and a non-destructive sugar content measurement method.

  Conventionally, the sugar content of fruits and vegetables has been measured by cutting and squeezing the measured fruits and vegetables, and measuring the sugar content of the resulting solution with a refractometer. However, even though this measuring method can be used for sampling inspection by sampling, it cannot be used for 100% inspection of fruits and vegetables shipped to the market. For this reason, only a statistical estimate of sugar content can be made, and fruits and vegetables with low sugar content are shipped with a certain probability, and there is a possibility that a complaint may be received from the market. In order to improve accuracy, a method of increasing the number of samplings is conceivable, but there is a problem in that the sugar content is not completely measured and the sugar content is destructively measured, so that an economic burden increases. Another method is to guarantee the sugar content by shipping as a sugar content slightly lower than the sugar content estimated by sampling, but the problem is that even fruits and vegetables with high sugar content can only be sold at the price of products with low sugar content. was there.

  In order to solve these problems, research on nondestructive sugar content measurement methods by near infrared spectroscopy has been actively conducted in recent years. As a non-destructive sugar content measurement method, for example, near infrared absorption spectrum is obtained by irradiating near infrared rays in the vicinity of or in contact with the measured fruits and vegetables, and the component content of the measured fruits and vegetables is obtained from the obtained near infrared absorption spectra. There is what is calculated (see Patent Document 1).

  By the way, as shown in FIG. 2, for example, from the sugar content distribution of the cross section of melon measured with a refractometer, it can be seen that the sugar content of fruits and vegetables varies considerably depending on the part. In the example of the melon of FIG. 2, the sugar content is small near the surface and the sugar content increases toward the center, and the sugar content near the center is about 2 to 3 times the sugar content near the surface. In addition, the sugar content near the surface is almost twice different depending on the location.

JP-A-1-216265

  In the method described in Patent Document 1, a coaxial glass fiber is used for irradiating near-infrared rays to the measured fruits and vegetables and receiving reflected light from the measured fruits and vegetables, so that only near-small areas on the surface of the measured fruits are irradiated with near-infrared rays. It is not possible to irradiate near infrared rays to the vicinity of the center of the measured fruit or vegetable. For this reason, the sugar content is calculated based on information by reflected light from a minute specific part near the surface of the measured fruit and vegetable, and there is a problem that the sugar content of the entire measured fruit and vegetable cannot be measured with high accuracy.

  On the other hand, in order to obtain near-infrared information by reaching the center of the measured fruit and vegetable, the energy of the light source that irradiates the near-infrared light may be increased. However, the method described in Patent Document 1 has a problem in that when the energy of the light source is increased and the fruit or vegetable to be measured is irradiated, the surface of the fruit or vegetable to be measured becomes hot and affects the fruit or vegetable to be measured.

  The present invention has been made paying attention to such a problem, and provides a non-destructive sugar content meter and a non-destructive sugar content measuring method capable of accurately measuring the sugar content of the entire measurement object without affecting the measurement object. It is intended to provide.

  In order to achieve the above object, a nondestructive saccharimeter according to the present invention irradiates a measurement object from a light source with near infrared light, receives near infrared light transmitted through the measurement object at a light receiving unit, and receives the light. A non-destructive saccharimeter for determining the sugar content of the object to be measured based on the absorbance at a specific wavelength of the transmitted light received by the unit, the table for placing the object to be measured, and the object to be measured on the table And rotating means for relatively rotating the light source around.

  The non-destructive sugar content measuring method according to the present invention irradiates a measurement object from a light source with near infrared rays, receives near infrared transmission light transmitted through the measurement object by a light receiving unit, and transmits transmitted light received by the light receiving unit. A non-destructive sugar content measuring method for obtaining a sugar content of the object to be measured based on absorbance at a specific wavelength, characterized in that the light source is relatively rotated around the object to be measured.

  The non-destructive sugar content meter and the non-destructive sugar content measuring method according to the present invention rotate the light source relatively around the object to be measured, so that the object to be measured is irradiated with near infrared rays from the light source in accordance with the rotation. By performing the measurement, the sugar content of the object to be measured can be obtained within the rotation range. When the measurement is performed by rotating the light source relatively and irradiating near-infrared rays to the entire circumference of the object to be measured, the sugar content in the entire circumference of the object to be measured can be obtained.

  In addition, since the light source is rotated relative to the object to be measured, the near-infrared irradiation from the light source does not concentrate on a specific part of the object to be measured, and the rise in the surface temperature of the object to be measured can be suppressed. it can. For this reason, the energy of the light source can be increased and irradiated without affecting the object to be measured, and the near infrared ray can reach the center of the object to be measured. When the irradiation energy of the light source is changed, the sugar content from the vicinity of the surface of the object to be measured to the center can be obtained.

  Thus, in the non-destructive sugar content meter and the non-destructive sugar content measuring method according to the present invention, not only information on a specific part near the surface of the object to be measured but also information on the entire circumference and surface to the center of the object to be measured can be obtained. The sugar content of the entire object to be measured can be accurately measured.

  Note that the light source may irradiate the object to be measured with near-infrared rays continuously in accordance with the rotation or intermittently. In this case, the sugar content can be obtained by continuously or intermittently receiving near-infrared transmitted light transmitted through the object to be measured by the light receiving unit corresponding to the irradiation of the light source. When a light source irradiates intermittently, it is preferable to irradiate for every predetermined rotation angle.

  In the non-destructive saccharimeter according to the present invention, the light source is composed of two or more, each light source is configured to irradiate the object to be measured with near infrared rays having the same intensity, You may arrange | position so that the circumference | surroundings may be divided | segmented at equal angles in the rotation direction by the said rotation means. In this case, the sugar content of the object to be measured in the rotation range of each light source can be determined simultaneously by shifting the irradiation timing of each light source. For this reason, when obtaining the sugar content in the entire circumference of the object to be measured, it is only necessary to rotate it by the angular interval at which each light source is arranged, and the measurement time can be shortened.

  The nondestructive sugar content meter according to the present invention preferably has a calculation means for obtaining an average value of absorbance at a specific wavelength from the transmitted light received by the light receiving unit and obtaining the sugar content of the object to be measured from the average value. In this case, the average sugar content of the entire object to be measured can be obtained.

  The non-destructive sugar content meter according to the present invention includes a start signal transmitting unit that transmits a start signal when the rotating unit starts rotating, a stop signal transmitting unit that transmits a stop signal when the rotating unit stops rotating, and the start It is preferable to have a control unit that starts irradiation of the light source by a start signal from the signal transmission unit and stops irradiation of the light source by a stop signal from the stop signal transmission unit. The nondestructive saccharimeter according to the present invention includes a start signal transmitting unit that transmits a start signal when the rotating unit starts rotating, and the rotating unit relatively positions the light source with respect to an object to be measured by the equal angle. A stop signal transmission unit that sends a stop signal when rotation is stopped when rotating, and starts irradiation of the light source by a start signal from the start signal transmission unit, and a stop signal from the stop signal transmission unit You may have the control part which stops irradiation. In this case, the control unit can automatically control the irradiation of the light source in accordance with the rotation state of the rotating means, and the sugar content can be automatically measured. The nondestructive saccharimeter according to the present invention includes a detection unit that detects a measurement object placed on a table, a rotation signal transmission unit that transmits a rotation signal when the detection unit detects the measurement object, and a rotation You may have a rotation control part which starts rotation of a rotation means by the rotation signal from a signal transmission part. In this configuration, the sugar content of the object to be measured can be automatically measured simply by placing the object to be measured on the table. For this reason, sugar content can be measured with high accuracy and efficiency at the time of 100% inspection or the like.

  ADVANTAGE OF THE INVENTION According to this invention, the nondestructive sugar content meter and the nondestructive sugar content measuring method which can measure the sugar content of the whole to-be-measured object accurately can be provided, without affecting to-be-measured object.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a nondestructive sugar content meter according to an embodiment of the present invention.
As shown in FIG. 1, the nondestructive sugar content meter 10 includes a mounting table 11, a rotating means 12, two light sources 13, a photoelectric conversion unit 14, an amplification unit 15, a control calculation unit 16, and a display unit 17. .

  The mounting table 11 is configured to place the DUT 1 on the top. The mounting table 11 can transmit the near-infrared transmitted light transmitted through the device under test 1 downward. The mounting table 11 has a gravity sensor (not shown) for detecting the object 1 to be measured placed thereon, and a detection signal output unit (not shown) for outputting a detection signal when the gravity sensor detects it. is doing. The DUT 1 is, for example, fruits and vegetables such as melon, tomato, apple, pear and peach.

  The rotating means 12 includes a turntable 21 and a rotation drive unit 22. The turntable 21 is provided around the mounting table 11 and is rotatable along the periphery of the mounting table 11 with the mounting table 11 as a center. The rotation drive unit 22 can control the rotation of the turntable 21.

  Each light source 13 includes a halogen lamp and is mounted on a turntable 21. Each light source 13 can be rotated relative to the object 1 to be measured on the mounting table 11 by the rotating means 12. Each light source 13 is arranged at a position facing each other with the mounting table 11 in between, and the periphery of the object 1 to be measured on the mounting table 11 is divided by 180 degrees at an equal angle in the rotation direction by the rotating means 12. ing. Each light source 13 is supplied with electric power from a power source 23 and irradiates the DUT 1 on the mounting table 11 with near infrared rays having the same intensity.

  The photoelectric conversion unit 14 is provided below the mounting table 11 and includes a light receiving unit (not shown), a band pass filter (not shown), and a photoelectric conversion element (not shown). The light receiving unit is a member that receives transmitted light of near infrared light that has passed through the mounting table 11. The band-pass filter has a plurality of different bands and passes only light having a specific wavelength of transmitted light received by the light receiving unit. The photoelectric conversion element is a member that converts light of a plurality of specific wavelengths that have passed through each bandpass filter into an electric signal and outputs the electric signal.

  Note that when the near-infrared rays emitted from each light source 13 pass through the DUT 1, a plurality of specific wavelength components having a high correlation with the sugar content are absorbed. In order to calculate the sugar content from the absorbance of the plurality of specific wavelength components that are absorbed, the plurality of specific wavelengths are selected as the band of the specific wavelength that each bandpass filter passes. Actually, a specific wavelength having a high correlation with the sugar content is selected as the pass wavelength band of each bandpass filter from the sugar content measured in advance by a refractometer.

The amplification unit 15 is a member that amplifies the electrical signal output from the photoelectric conversion unit 14 for each specific wavelength.
The control calculation unit 16 includes a calculation unit (not shown) and a control unit (not shown). The calculating means performs analog / digital conversion of the electrical signal of each specific wavelength amplified by the amplifying unit 15 and calculates the absorbance for each specific wavelength. Moreover, the calculation means can calculate the average value of the absorbance determined corresponding to the irradiation of the light source 13 a plurality of times for each specific wavelength. Further, the calculation means obtains the sugar content of the DUT 1 from the calculated absorbance for each specific wavelength or the average value of the absorbance.

The control unit can control the rotation driving unit 22 and the power source 23. The control unit can receive a detection signal from the detection signal output unit of the mounting table 11. When receiving the detection signal, the control unit controls the rotation driving unit 22 to rotate the rotation table 21 and simultaneously controls the power source 23. Then, the irradiation of each light source 13 is started. In addition, when the rotating unit 12 rotates each light source 13 relative to the DUT 1 by 180 degrees, the control unit controls the rotation driving unit 22 to stop the turntable 21 and simultaneously turn the power source 23 on. It is configured to control and stop the irradiation of each light source 13.
The display unit 17 can display the sugar content of the DUT 1 obtained by the calculation means.

With the non-destructive sugar content meter 10, a non-destructive sugar content measurement method can be carried out as follows.
First, when the DUT 1 is placed on the mounting table 11, the gravity sensor detects the DUT 1, and the detection signal output unit outputs a detection signal. The control unit of the control calculation unit 16 receives the detection signal, controls the rotation drive unit 22 to rotate the turntable 21, and simultaneously controls the power source 23 to start irradiation of each light source 13.

  Each light source 13 intermittently irradiates the device under test 1 with a near infrared ray at every predetermined rotation angle while rotating around the device under test 1 by the rotating means 12. At this time, in order to prevent the absorbance from being calculated based on information biased to a specific part of the DUT 1 and improve the measurement accuracy, the irradiation is performed as densely as possible at equal angular intervals. Further, irradiation is performed by shifting the irradiation timing of each light source 13. Further, irradiation is performed by changing the irradiation energy of each light source 13 so as to obtain the sugar content from the vicinity of the surface of the DUT 1 to the center.

  Near-infrared transmitted light that has passed through the DUT 1 is received by the light receiving unit of the photoelectric conversion unit 14, and each bandpass filter passes only light of each specific wavelength of the transmitted light received by the light receiving unit. The conversion element converts the light of each specific wavelength into an electrical signal and outputs it. The output electrical signal is amplified by the amplification unit 15 for each specific wavelength. The amplified electric signal for each specific wavelength is converted from analog to digital by the calculation means of the control calculation unit 16, and the absorbance is calculated for each specific wavelength. Further, the sugar content of the DUT 1 is obtained from the absorbance by the calculation means. At this time, the sugar content is calculated by obtaining the product of the coefficient calculated by the correlation with the sugar content measured in advance with a refractometer and the absorbance for each specific wavelength, and obtaining the sum thereof. The obtained sugar content is displayed on the display unit 17.

  When the rotating means 12 rotates each light source 13 relative to the DUT 1 by 180 degrees, the control unit of the control calculation unit 16 controls the rotation driving unit 22 to stop the turntable 21, and at the same time The power source 23 is controlled to stop the irradiation of each light source 13. For each specific wavelength, the average value of the absorbance determined corresponding to the irradiation of each rotating light source 13 is calculated for each specific wavelength, and the average of the entire object to be measured 1 is calculated from the average value of the absorbance. Find sugar content. The obtained average sugar content of the entire device under test 1 is displayed on the display unit 17.

  As described above, in the non-destructive sugar content meter 10 and the non-destructive sugar content measurement method according to the embodiment of the present invention, each light source 13 is relatively rotated around the object 1 to be measured. By irradiating near-infrared rays from the light source 13 to the object 1 to be measured, the sugar content of the object 1 can be determined within the rotation range. Since each light source 13 is rotated relatively to irradiate the entire circumference of the DUT 1 with near-infrared rays and the measurement is performed, the sugar content of the DUT 1 can be obtained.

  Further, since each light source 13 is rotated relative to the device under test 1 around it, the near-infrared irradiation from each light source 13 does not concentrate on a specific part of the device under test 1, and the surface of the device under test 1. An increase in temperature can be suppressed. For this reason, the energy of the light source 13 can be increased and irradiated without affecting the device under test 1, and near infrared light can reach the center of the device under test 1. Since the irradiation energy of each light source 13 is changed, the sugar content from the vicinity of the surface of the DUT 1 to the center can be obtained.

  Thus, the non-destructive sugar content meter 10 obtains not only information on a specific part near the surface of the object 1 to be measured but also information on the entire circumference and the surface to the center of the object 1 to be measured. The sugar content can be measured with high accuracy.

  Further, since the non-destructive sugar content meter 10 shifts the irradiation timing of each light source 13, the sugar content of the DUT 1 within the rotation range of each light source 13 can be obtained simultaneously. For this reason, when calculating | requiring the sugar content in the perimeter of the to-be-measured object 1, what is necessary is just to rotate only the angular space | interval where each light source 13 is arrange | positioned, and measurement time can be shortened. Since the sugar content of the device under test 1 can be automatically measured simply by placing the device under test 1 on the mounting table 11, the sugar content can be measured with high accuracy and efficiency at the time of 100% inspection or the like. be able to.

  Note that the number of light sources 13 is not limited to two, and may be one or three or more. When there are three or more light sources 13, the light sources 13 are arranged so as to divide the circumference of the DUT 1 on the mounting table 11 at an equal angle in the rotation direction by the rotating means 12. The product of the rotation angle 21 and the rotation angle of 21 is 360 degrees or more. Thereby, near infrared rays can be irradiated to the entire circumference of the DUT 1. For example, when there are three light sources 13, the rotation angle of the turntable 21 is 120 degrees or more, and when there are four light sources 13, the rotation angle of the turntable 21 is 90 degrees or more.

  Further, instead of rotating the turntable 21, the placement table 11 may be rotated with respect to the turntable 21, and the rotation of the placement table 11 may be controlled by the rotation drive unit 22. In this case, since the light source 13 rotates relative to the object to be measured 1 on the mounting table 11, the same effect as in the case where the rotating table 21 rotates can be obtained.

It is a block diagram which shows the nondestructive sugar content meter of embodiment of this invention. It is (a) longitudinal cross-sectional view which shows the sugar content distribution of the melon measured with the conventional refractometer, and (b) is a cross-sectional view.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 to-be-measured object 10 Nondestructive sugar content meter 11 Mounting stand 12 Rotating means 13 Light source 14 Photoelectric conversion part 15 Amplifying part 16 Control calculating part 17 Display part 21 Turntable 22 Rotation drive part 23 Power supply

Claims (6)

The near-infrared light is irradiated from the light source to the object to be measured, and the near-infrared transmitted light that has passed through the object to be measured is received by the light-receiving unit. A non-destructive sugar content meter for determining sugar content,
A table for placing an object to be measured;
A rotating means for rotating the light source relative to the object to be measured on the table;
A non-destructive sugar content meter characterized by comprising:   The light source is composed of two or more, each light source has a configuration that irradiates the object to be measured with near-infrared rays having the same intensity, and the periphery of the object to be measured on the table is rotated in the direction of rotation by the rotating means. The nondestructive sugar content meter according to claim 1, wherein the non-destructive sugar content meter is arranged so as to be divided at an angle.   3. The nondestructive device according to claim 1, further comprising a calculation unit that obtains an average value of absorbance at a specific wavelength from transmitted light received by the light receiving unit, and obtains the sugar content of the object to be measured from the average value. Sugar meter. A start signal transmitter for sending a start signal when the rotating means starts rotating;
A stop signal transmitter for sending a stop signal when the rotating means stops rotating;
Having a control unit that starts irradiation of the light source by a start signal from the start signal transmission unit and stops irradiation of the light source by a stop signal from the stop signal transmission unit;
The nondestructive sugar content meter according to claim 1, 2, or 3. A start signal transmitter for sending a start signal when the rotating means starts rotating;
A stop signal transmitter for sending a stop signal when the rotation means stops the rotation when the light source is rotated relative to the object to be measured by the equal angle; and
Having a control unit that starts irradiation of the light source by a start signal from the start signal transmission unit and stops irradiation of the light source by a stop signal from the stop signal transmission unit;
The nondestructive sugar content meter according to claim 2 or 3, wherein   The near-infrared light is irradiated from the light source to the object to be measured, and the near-infrared transmitted light that has passed through the object to be measured is received by the light-receiving unit. A non-destructive sugar content measuring method for obtaining a sugar content, wherein the light source is rotated relative to an object to be measured around the non-destructive sugar content measuring method.

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