JP3847285B2 - Spectroscopic analyzer - Google Patents

Description

The present invention relates to a conveying unit that conveys the measurement object at a set speed so as to pass through the measurement target part, a light projecting unit that irradiates light to the measurement object located at the measurement target part, and the measurement object A light receiving means for receiving and spectrally transmitting the transmitted light from the light and measuring the dispersed light; and a control means for controlling the operation of each part. The control means is configured to receive light received by the light receiving means. The invention relates to a spectroscopic analyzer configured to analyze the internal quality of the object to be measured.

The spectroscopic analysis apparatus of the present invention includes a conveying unit that conveys the measurement object at a set speed so as to pass through the measurement target part, a light projecting unit that irradiates light to the measurement object located in the measurement target part, A light receiving means for receiving and splitting the transmitted light from the object to be measured and measuring the dispersed light, and a control means for controlling the operation of each part;
The control means is configured to analyze the internal quality of the object to be measured by the light received by the light receiving means,
The first feature structure, the disposed such that the received light quantity measured object reaches the measurement target portions is decreased, the light amount detecting sensor for detecting that the object to be measured has reached the measurement target portions Is provided in the light receiving means ,
The light-receiving means rotates a disk formed with slits that allow a plurality of light beams to pass radially around the longitudinal axis, thereby allowing the light that has passed through the object to be measured to pass and the passage of the light. A shutter mechanism that can be switched between a blocking state and a blocking state, and when light that has passed through the shutter mechanism in the open state is incident, the light is dispersed and the spectrum data is measured by a charge accumulation type light receiving sensor. It is configured with a vessel,
The control means detects whether or not the measurement object has reached the measurement target location based on a change in the amount of received light detected by the light amount detection sensor, and the measurement object has arrived When the shutter is detected, the shutter mechanism is switched to the open state, and the shutter mechanism is switched to the shielding state after the open state is maintained for the open maintaining time .

In the second feature configuration, in addition to the first feature configuration, the light receiving unit reflects light in a wavelength range of a measurement target among light transmitted through the measurement object, and emits light of other wavelengths. Constructed with a bandpass mirror to pass through,
The shutter mechanism is provided so as to be switchable between the open state that allows light reflected by the bandpass mirror to pass through and the shielding state that blocks passage of the light,
The light amount detection sensor is provided so as to detect a light amount of light passing through the band pass mirror .

The third feature configuration is characterized in that, in addition to the first or second feature configuration, the light receiving means is configured to be movable in a perspective direction with respect to the measurement target location.
The fourth feature configuration is characterized in that, in addition to any of the first to third feature configurations, the light projecting means is configured to be movable in a perspective direction with respect to the measurement target location.
The fifth characteristic configuration is characterized in that, in addition to the fourth characteristic configuration, the vertical positions of the light projecting means and the light receiving means are changed and adjusted.

  Hereinafter, the data processing apparatus for a spectroscopic analysis apparatus according to the present invention is applied to a process for a spectroscopic analysis apparatus for measuring, for example, internal quality information (sugar content, acidity, etc.) of a mandarin orange as a measurement object M in the drawings. This will be explained based on.

First, the configuration and measurement operation of the spectroscopic analyzer will be described.
As shown in FIG. 1, the spectroscopic analysis device includes a light projecting unit 1 that irradiates light to the measurement object M, and the light that has passed through the measurement object M as measurement target light. A light receiving unit 2 that receives spectral measurement target light and obtains spectral spectrum data, an arithmetic process that analyzes the internal quality of the measurement object M based on the spectral spectrum data, and an operation control process that controls the operation of each unit. The measurement object M is configured to include the control unit 3 and the like to be executed, and is configured such that the object to be measured M is placed and conveyed in a single line in a row at a set speed by the conveyor 6 and sequentially passes through the measurement target portion T. ing. And with respect to the to-be-measured object M located in the measurement target location T, the light projected from the light projecting unit 1 is transmitted through the to-be-measured object M, and then received by the light receiving unit 2. The light receiving unit 2 is arranged so as to be distributed to both the left and right side portions of the measurement target portion T.

The light projecting unit 1 includes a light projecting means 7 configured to be movable in a perspective direction with respect to the measurement target location T and irradiating light to the measurement object M located at the measurement target location T. The light receiving unit 2 includes a light receiving unit 8 configured to be movable in the perspective direction with respect to the measurement target location T, receiving and spectrally transmitting the transmitted light from the measurement target M, and measuring the split light. Is provided.
Further, in the light projecting unit 1, as the light projecting position adjusting means 4, a screw rod 12a rotatably supported by the bearing 11a and provided along the perspective direction with respect to the measurement target location T, and the screw rod 12a. A pulse motor 13a that is connected to one end of the motor and controlled by the control unit 3, and a nut member 14a that fits externally on the screw rod 12a. The light projecting means 7 is located above the gantry 15a that includes the nut member 14a. Is attached. Then, when the control unit 3 rotates the pulse motor, the position of the light projecting means 7 is changed and adjusted along the perspective direction with respect to the measurement target location T, and the measurement object M located at the measurement target location T. And the light projecting means 7 can be changed and adjusted.
Similarly, the light receiving section 2 also includes a bearing 11b, a screw rod 12b, a pulse motor 13b, and a nut member 14b as the interval maintaining means 5, and the light receiving means 8 includes a base 15b having a nut member 14b. It is attached above. Then, the position of the light receiving means 8 is changed and adjusted along the perspective direction with respect to the measurement target location T, and the interval between the measurement object M located at the measurement target location T and the light receiving means 8 is maintained at the set interval. It is configured as follows.

Next, the configuration of the light projecting means 7 will be described.
As shown in FIG. 2, the light projecting means 7 reflects a light source 21 composed of a halogen lamp inside a light projecting frame 28 and a light emitted from the light source 21 to focus on the surface of the object M to be measured. A concave-shaped light reflecting plate 22 for matching the light, and the light after being condensed by passing through a small-diameter transmission hole positioned near the focal position of the light condensed by the light reflecting plate 22 A diaphragm plate 23 serving as a diaphragm means for suppressing spread outward in the radial direction, a light projection shutter that can be switched between a state in which light from the light source 21 is irradiated on the measurement target location T and a state in which the light is blocked. The mechanism 24, a collimating lens 25 for projecting light that changes the condensed light from the light source 21 into parallel light, and sideways toward the object M to be measured positioned at the measurement target location T by reflecting the light that has changed into parallel light. Projection reflector 26 to be changed to, and this projection mirror It is constituted by a light projecting condenser lens 27 for condensing the reflected light at 6.
Although not described in detail, the light projecting shutter mechanism 24 swings the shielding plate by an operating mechanism using an electric motor to block the light from being irradiated on the measurement target portion T. It is the structure which switches to the state to perform.

  As shown in FIG. 3, the light receiving unit 8 includes a light receiving condensing lens 31 that condenses measurement target light that has passed through the measurement object M, and a light receiving condensing lens 31. A bandpass mirror that reflects upward only the light in the wavelength range (600 nm to 1000 nm) of the measurement target as will be described later, and passes the light of other wavelengths as it is. 32. A light-receiving shutter mechanism 33 that can be switched between an open state in which the measurement target light reflected upward by the band-pass mirror 32 is allowed to pass through and a shielding state in which the measurement target light is prevented from passing through. When light that has passed through the shutter mechanism 33 is incident, the light travels straight through the spectroscope 34 and the bandpass mirror 32 that measure the spectral data by dispersing the light. It is configured to include a light-power detection sensor 35 for detecting the amount of light passing through in state.

As shown in FIG. 4, the spectroscope 34 includes a light receiving reflecting mirror 37 that reflects the measurement target light incident from the light entrance 36, and concave diffraction that splits the reflected measurement target light into light of a plurality of wavelengths. The light receiving sensor 39 that measures spectral spectrum data by detecting the light intensity for each wavelength in the measurement target light spectrally separated by the concave diffraction grating 38 includes a light shielding material that shields light from the outside. It becomes the structure arrange | positioned in the dark box 40 which becomes. The light receiving sensor 39 is composed of a 1024-bit MOS type line sensor that simultaneously receives the light spectrally reflected by the concave diffraction grating 38 for each wavelength and converts it into a signal for each wavelength and outputs it. . Although not described in detail, this line sensor outputs a photoelectric conversion element such as a photodiode for each unit pixel, a capacitor for accumulating the charge obtained by the photoelectric conversion element, and the accumulated charge to the outside. The drive circuit for this is built in.
The charge accumulation time by the capacitor can be changed from the outside via a drive circuit.

  As shown in FIG. 5, the light receiving shutter mechanism 33 includes a disk 42 in which a plurality of slits 41 are radially formed in a state of being rotated around a vertical axis by a shutter pulse motor 43. When the slits 41 overlap with each other in the light entrance 36 of the dark box 40, the slit 41 is in an open state where light is allowed to pass therethrough, and when the position of the slit 41 is shifted, the slit 41 is blocked. A transmission hole 44 having substantially the same shape is formed, and the disk 42 is arranged so as to slide in close contact with the light entrance 36 of the dark box 40 so as not to leak light. That is, the light receiving shutter mechanism 33 is provided in the state of being close to the light entrance 36 for the concave diffraction grating 38.

As described above, the light projecting unit 7 and the light receiving unit 8 are configured such that their positions are changed and adjusted along the perspective direction with respect to the measurement target location T, and the object M to be measured is The frame body 55 is provided in a state of being integrally supported by a frame body 55 provided so as to bypass the upper side of the passing measurement target location T. The overall vertical position can be changed and adjusted. Although not described in detail, the vertical adjustment mechanism 61 can be moved up and down by a screw feed mechanism 64 that is installed in a fixed position with respect to the fixing portion 62 and driven by an electric motor 63 for vertical position adjustment. It is like that.
And the reference filter 65 which is an example of a reference | standard body is provided in the state fixed to the upper side of the passage location of the to-be-measured object M in the conveyance conveyor 6, and the position fixed by the fixing | fixed part 62. The reference filter 65 is composed of an optical filter having a predetermined absorbance characteristic, and specifically is composed of opal glass.

  Then, by adjusting the position of the entire frame 55 in the vertical direction, the light from the light projecting means 7 is transmitted through the measurement object M placed on the conveyor 6 as shown in FIG. And the normal measurement state in which the light is received by the light receiving means 8, and the light from each light projecting means 7 is received by the light receiving means 8 after passing through the reference filter 65 as shown in FIG. It can be switched to the reference measurement state.

  The transport conveyor 6 is configured to be rotationally driven by attaching a bucket 6b for placing an object to be measured M at a set interval to an endless rotating chain 6a. As shown in FIG. An optical passage sensor 45 that outputs a detection signal every time the central position of the bucket 6b passes is provided at a location on the upper side in the transport direction of the measurement target location T. That is, the passage sensor 45 functions as a conveyance cycle detection unit that detects a cycle in which the measurement object M passes through the measurement target portion T.

The control unit 3 is configured by using a microcomputer. As shown in FIG. 9, the control unit 3 analyzes the internal quality of the measurement object M based on the spectral data obtained by the spectroscope 34. The operation control means 101 as a control means for controlling the operation of each part is provided in a control program format.
That is, as described above, the change adjustment operation of the light projection position adjusting unit 4, the change adjustment operation of the interval maintaining unit 5, the opening / closing operation of each shutter mechanism 24, 33, the operation of the vertical adjustment mechanism 61, and the light receiving sensor 39 While controlling the operation | movement of each part, such as management of operation | movement, it becomes the structure which performs the arithmetic processing which analyzes the internal quality of the to-be-measured object M using the spectral analysis method which is a well-known technique which is mentioned later.

  Then, based on the product information about the size of the measurement object M input in advance, the control unit 3 determines that the measurement object M has a small size as shown in FIG. The light projecting means 7 and the light receiving means 8 are operated by operating the vertical adjustment mechanism 61 so that the light from the light projecting means 7 is irradiated uniformly over the entire object to be measured M around the center of the object to be measured M. And the control unit 3 rotates the pulse motor 13a of the light projecting position adjusting unit 4 so that the focal position of the focused light emitted from the light projecting unit 7 is set to the measurement target location T. The position of the light projecting means 7 is changed and adjusted so as to approach the measurement target location T so as to coincide with the surface of the smallest estimated object M to be measured, and the pulse motor 13b of the interval maintaining means 5 is rotated. , The most presumed to be located at the measurement target point T So as to maintain the distance between the listening object to be measured M and the light-receiving unit 8 to set the interval, to adjust changes in the direction to approach the position of the light receiving unit 8 to the measurement target portions T. Further, even in the case of a product with a large size of the object M to be measured, as shown in FIG. 8B, the vertical adjustment mechanism 61 moves the light projecting means 7 and the light receiving means 8 upward, While adjusting so that the light from the light projecting means 7 is irradiated to the whole of the measured object M around the central portion of the measured object M, the control unit 3 rotates the pulse motor 13a of the light projecting position adjusting means 4. Thus, the position of the light projecting means 7 is measured so that the focal position of the focused light emitted from the light projecting means 7 coincides with the surface of the smallest object M to be estimated located at the measurement target location T. The distance between the target object T and the light receiving means 8 is adjusted by changing and adjusting the direction away from the target part T, and the pulse motor 13b of the interval maintaining means 5 is rotated to set the distance between the largest object M to be measured and the light receiving means 8 located at the measurement target part T. So that the position of the light receiving means 8 is To adjust changes in the direction away from the target point T.

  That is, the light from the light projecting means 7 is irradiated uniformly over the entire measurement object M around the central portion of the measurement object M, and the measurement object M is not passed through the measurement object M. The vertical position of the light projecting means 7 and the light receiving means 8 is adjusted in order to prevent the light from entering and entering the spectroscope 34, and the distance between the light projecting means 7 and the measurement object M, and By adjusting the distance between the measured object M and the light receiving means 8, the light irradiated from the light projecting means 7 is accurately incident on the measured object M in a focused state, and the light receiving means 8 sets an appropriate amount. As a result, the ambient light can be measured while preventing the charge accumulation amount of the light receiving sensor 39 from being insufficient and the S / N (signal to noise) ratio from being lowered. M is prevented from entering the light receiving means 8 mixed with the detection light transmitted through M, and In which the charge accumulation amount of the light receiving sensor 39 amount deviates from the set appropriate range is configured to prevent the put away saturation.

  Note that the measurement conditions to be input in advance may be input to the control unit 3 before placing the measurement object M on the transfer conveyor 6 or the transfer conveyor 6 when the type or size of the measurement object M changes. Then, the measurement condition is detected in the middle of conveying the measurement object M to the measurement target location T, and the detected measurement condition is input to the control unit 3.

Next, a control operation by the operation control unit 101 will be described.
Prior to normal measurement of the measurement object M, the operation control means 101 irradiates the reference filter 65 with light from the light projecting means 7 instead of the measurement object M, and transmits light from the reference filter 65. Is measured by the spectroscope 34, and the spectral data obtained by receiving the spectrally separated light is obtained as a reference data measurement mode for obtaining the light quantity reference spectral data, and the measurement object M conveyed by the conveyor 6. On the other hand, normal data for irradiating light from the light projecting means 7 to obtain measured spectral data and analyzing the internal quality of the measurement object M based on the measured spectral data and the light quantity reference spectral data. It can be switched to the measurement mode.

  More specifically, in the reference data measurement mode, the calibration data measurement state is switched to a state in which the conveyance of the object M to be measured by the conveyor 6 is stopped. Then, the light receiving shutter mechanism 33 is switched to the open state, the light from the light projecting means 7 is irradiated to the reference filter 65 in place of the measurement object M, and the transmitted light from the reference filter 65 is spectrally separated. Spectral data obtained by spectroscopically receiving the dispersed light by the instrument 34 is measured as reference spectral data.

  In the reference data measurement mode, the detection value (dark current data) of the light receiving sensor 39 in the non-light state where the light to the spectroscope 34 is blocked is also measured. That is, the light receiving shutter mechanism 33 of the spectroscope 34 is switched to the shielding state, and the detection value for each unit pixel of the light receiving sensor 39 at that time is obtained as dark current data.

Next, the control operation in the normal data measurement mode will be described.
In this normal data measurement mode, the vertical adjustment mechanism 61 is operated to switch the frame 55 to the normal measurement state, and the object to be measured M is conveyed by the conveyor 6. Then, based on the detection information from the passage sensor 45, the period during which the measurement object M passes through the measurement target location T is detected, and in the state synchronized with the period, the dispersed light is received and the charge accumulation operation is set. The operation of the light receiving sensor 39 is controlled so that the charge accumulation process executed for a time and the sending process for sending out the accumulated charge are repeated at a set cycle.
That is, as shown in FIG. 10, in the time zone in which each measurement object M is predicted to pass through the measurement target location T, the light receiving sensor 39 executes the charge accumulation process for the set time T1, and the measurement object M measures. The sending process for sending out the accumulated charges for the set time T2 is executed at a timing such that the vicinity of the intermediate position between the measured objects M that are predicted not to exist in the target place T is located at the measurement target place T. The operation of the light receiving sensor 39 is controlled. Therefore, this measuring apparatus is configured to operate with the charge accumulation time by the light receiving sensor 39 always being constant. If the processing capability is such that seven objects to be measured M pass every second, the set time T1 for executing the charge accumulation processing is about 140 msec.

Then, the operation control means 101 switches the open state from the shield state to the open state when the light receiving sensor 39 performs the charge accumulation process and the light reception sensor 39 performs the charge accumulation process. It is configured to control the operation of the light receiving shutter mechanism 33 so as to return to the shielding state after being maintained for a while, and is configured to change and adjust the opening maintaining time Tx based on change command information.
This open maintenance time Tx is configured to be changed according to the type of the object to be measured M. For example, in Satsuma mandarin, light is relatively easy to transmit, so it is set to a relatively short time (about 10 msec). For Iyokan, it is difficult to transmit light, so a long time (about 30 msec) Set to.
The setting of the operation condition depending on the kind of the product is configured to be manually performed by an operator. That is, as shown in FIG. 9, there is provided an artificial operation type switching operation tool 66 for artificially switching the setting position according to the type of product, and setting information of the switching operation tool 66 is input to the control unit 3. The control unit 3 is configured to change and adjust the opening maintenance time Tx according to the setting information.

Further, the operation control means 101 detects the measured object M at the measurement target location T based on the change in the measured amount of light received by the light quantity detection sensor 35, that is, the light transmission amount of the measured object M. Whether or not the object to be measured M has arrived is detected, the light-receiving shutter mechanism 33 is switched to the open state, and the light-receiving shutter mechanism 33 is kept open for the open maintaining time Tx. The measurement shutter mechanism 33 is switched to the shielding state and the measurement process is terminated.
More specifically, FIG. 11 shows a change state of the detection value of the light amount detection sensor 35 over time. The maximum value is output by the light projected from the light projecting means 7 until the measurement object M arrives. However, when the measurement object M reaches the measurement target location T, the measurement light is blocked and the light amount is detected. When the detection value (the amount of received light) of the sensor 35 starts to decrease and the detection value decreases to a preset value or less (t1), it is determined that the measurement object M has reached the measurement target location T, When the set time has elapsed from that point (t2), the light receiving shutter mechanism 33 is switched to the open state. Then, after maintaining the open state for the open maintaining time Tx, the light receiving shutter mechanism 33 is switched to the shielded state.

And the said calculating means 100 is comprised so that the calculation process which analyzes the internal quality of the to-be-measured object M using the spectral analysis method which is a well-known technique based on the various data obtained in this way may be performed. Yes.
That is, the measured spectral spectrum data obtained as described above is normalized using the reference spectral spectrum data obtained in the reference data measurement mode and the dark current data, and is obtained for each wavelength that is spectrally separated. Absorbance spectrum data is obtained, and a second derivative value of the absorbance spectrum data is obtained. And it is comprised so that the analytical calculation process which calculates the component amount corresponding to the sugar content contained in the to-be-measured object M and the component amount corresponding to acidity by the secondary differential value may be performed.
The absorbance spectrum data d is Rd as the reference spectrum data, Sd as the measured spectrum data, and Da as the dark current data.

[Equation 1]
d = log {(Rd−Da) / (Sd−Da)}

It is calculated by the following formula.
And the control part 3 uses the value of a specific wavelength among the values which carried out the secondary differentiation of the absorbance spectrum data d obtained in this way, and the measurement object M using the calibration formula shown by the following formula 2. The amount of components contained in is calculated.

[Equation 2]
Y = K0 + K1 · A (λ1) + K2 · A (λ2)

However,
Y: Component amount K0, K1, K2; Coefficients A (λ1), A (λ2); Second derivative of absorbance spectrum at specific wavelength λ

  For each component for calculating the component amount, a specific component amount calculation formula, specific coefficients K0, K1, K2, wavelengths λ1, λ2, and the like are preset and stored. The component amount of each component is calculated using a specific calibration formula for each component.

[Another embodiment]
Next, another embodiment will be described.
(1) In the above-described embodiment, the light projecting unit includes the halogen lamp, the reflector, and the light reflecting reflector. However, the present invention is not limited to this.
For example, a mercury lamp, a Ne discharge tube, or the like may be used as the light source, or a beam light source that can change the irradiation range by the beam light may be used as the light projecting means.

( 2 ) In the said embodiment, although sugar content and acidity were illustrated as internal quality of a to-be-measured object, not only this but internal quality other than that, such as taste information, may be measured.

( 3 ) In the above embodiment, a filter made of opal glass is used as the reference body. However, the present invention is not limited to this, and any material having a predetermined absorbance characteristic may be used in addition to a diffuser plate such as ground glass. Not.
The light receiving means is not limited to the MOS type line sensor, and other detection means such as a CCD type line sensor may be used.

Schematic configuration diagram of a spectroscopic analyzer Configuration diagram of light projection means Configuration diagram of light receiving means Spectrometer configuration diagram Diagram showing shutter mechanism Plan view showing the installation state of the passage sensor Diagram showing the vertical position change state The figure which shows the position adjustment state of the light projection means and light reception means with respect to the to-be-measured object of a different magnitude | size Control block diagram Timing chart of measurement operation Diagram showing change in received light quantity and measurement timing

Explanation of symbols

3 Control means 6 Transport means 7 Light projecting means 8 Light receiving means
32 Bandpass mirror
33 Shutter mechanism
34 Spectrometer 35 Light quantity detection sensor
39 Light receiving sensor
42 Disc M Object T T

Claims (5)

Transport means for transporting the object to be measured at a set speed so as to pass through the measurement target location;
A light projecting means for irradiating light to the object to be measured located at the measurement target location;
A light receiving means for receiving and splitting the transmitted light from the object to be measured, and measuring the split light;
And a control means for controlling the operation of each part,
The control means is a spectroscopic analyzer configured to analyze the internal quality of the object to be measured by the light received by the light receiving means,
Wherein provided as the light receiving amount measured object reaches the measurement target portions is decreased, the light amount detecting sensor for detecting that the object to be measured has reached the measurement target portions is the light receiving means Provided ,
The light-receiving means rotates a disk formed with slits that allow a plurality of light beams to pass radially around the longitudinal axis, thereby allowing the light that has passed through the object to be measured to pass and the passage of the light. A shutter mechanism that can be switched between a blocking state and a blocking state, and when light that has passed through the shutter mechanism in the open state is incident, the light is dispersed and the spectrum data is measured by a charge accumulation type light receiving sensor. It is configured with a vessel,
The control means detects whether or not the measurement object has reached the measurement target location based on a change in the amount of received light detected by the light amount detection sensor, and the measurement object has arrived The spectroscopic analysis device is configured to switch the shutter mechanism to the open state when detecting the signal, and to switch the shutter mechanism to the shielded state after maintaining the open state for an open maintaining time . The light receiving means is configured to include a bandpass mirror that reflects light in a wavelength range of a measurement target among light transmitted through the object to be measured and allows light of other wavelengths to pass through.
The shutter mechanism is provided so as to be switchable between the open state that allows light reflected by the bandpass mirror to pass through and the shielding state that blocks passage of the light,
The spectroscopic analyzer according to claim 1 , wherein the light amount detection sensor is provided so as to detect a light amount of light that has passed through the band pass mirror . The spectroscopic analyzer according to claim 1 or 2, wherein the light receiving means is configured to be movable in a perspective direction with respect to the measurement target portion .   The spectroscopic analyzer according to claim 1, wherein the light projecting unit is configured to be movable in a perspective direction with respect to the measurement target portion.   The spectroscopic analysis apparatus according to claim 4, wherein the vertical position of the light projecting unit and the light receiving unit is changed and adjusted.

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