JPH06170106A - Crystal growth monitoring apparatus - Google Patents

Abstract

PURPOSE:To precisely judge the crystal condition based on the direct parameters from image data. CONSTITUTION:A crystal growth monitoring apparatus 10 consists of an input apparatus 12 to obtain image data G by photographying growing crystal, a parameter extracting means 14 to extract parameters Xn from image data G in order to judge the growing condition of the crystal, a detecting value memorizing means 16 to memorize the parameters Xn as detected values Xn(t). It also consists of a standard value memorizing means 18 in which the standard value SXn(t) of the parameters at the time of normal growth of the crystal and growth condition SYn(t) corresponding to the standard value SXn(t) are previously memorized, a judging means 20 to judge the growing condition Yn(t) corresponding to the detected value Xn(t) by comparing the detected value Xn(t) with the standard value SXn(t), and an output apparatus 22 to send out at least the growth condition Yn(t).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crystal growth monitoring device for monitoring the growth of crystals and judging the progress of crystal growth, quality, normality, abnormality and the like.

[0002]

2. Description of the Related Art As a conventional technique, a crystal growth monitoring device used for a sugar crystal can will be described as an example. As a device of this type, a hardness meter called a rheometer is generally used.
The rheometer has a structure like a stirrer, and indirectly determines the state of crystal growth by rotating an impeller in a white space inside a crystal can to detect an apparent viscosity.

[0003]

However, the apparent viscosity obtained by the rheometer is not a direct reflection of the crystalline state. The reason is as follows.

In the crystal can, the solution is heated and concentrated under vacuum to produce sugar crystals. In this process, it is necessary to efficiently grow a crystal that precipitates with a seed crystal as a nucleus, and to satisfy the contradictory requirements of suppressing the generation of force grains (pseudocrystals) that precipitate without a seed crystal as a nucleus. Further, a change in the internal energy, such as precipitation, is unstable and has the property of maintaining the current state. Therefore, the state change occurs rapidly.

As described above, it is extremely difficult to accurately judge a defect in crystal precipitation and crystal growth that causes a sudden change under a delicate condition based on the apparent viscosity. Hereinafter, a specific example will be described. (A) Force grains are extremely small when they occur, and do not affect the apparent viscosity until they reach a certain size. Therefore, the force grain becomes considerably large by the time the apparent viscosity changes, and the timing of supplying water or sugar solution may be missed in order to suppress the germination of the force grain. (B) It is difficult or impossible to detect the following state by the apparent viscosity. Small crystals adhere to the surface of the crystals. The two crystals stick to each other and appear as a single crystal. A large number of minute crystals adhere to each other, and apparently become one crystal.

Therefore, an object of the present invention is to provide a crystal growth monitor capable of accurately determining a crystal state by a direct parameter from image data.

[0007]

A crystal growth monitoring apparatus according to the present invention comprises a parameter extracting means for extracting a parameter for determining a crystal growth state from image data of a crystal, and a detected value of the extracted parameter. As a detection value storage means, a reference value storage means pre-stored a reference value consisting of the parameter when the crystal grows and a growth state corresponding to this reference value, the detection value and the reference value And a determination unit that determines the growth state corresponding to the detected value. In addition, an input device that captures image data of a growing crystal to obtain image data, a parameter extraction unit that extracts a parameter for determining the growth state of the crystal from the image data, and the extracted parameter as a detection value. Detection value storage means to store, reference value storage means pre-stored a reference value consisting of the parameters when the crystal grew normally and the growth state corresponding to this reference value, the detection value and the reference value It may be provided with a determination means for comparing the above-mentioned and the growth state corresponding to the detected value, and an output device for outputting at least the determined growth state.

The above parameters include the overall brightness of the crystal and its background, the brightness of the background of the crystal,
The size of the crystal, the variation in the size of the crystal, the shape of the crystal, the ratio of the shape of the crystal for each type, the density of the crystal, and the like.

[0009]

The input device images the growing crystal to obtain image data. This image data is processed by the parameter extracting means, and parameters for determining the crystal growth state are extracted from the image data. The extracted parameter is stored as a detected value in the detected value storage means. The reference value storage means stores in advance a reference value composed of the above parameters when the crystal grows normally and a growth state corresponding to this reference value. The determination means compares the detected value with the reference value to determine the growth state corresponding to the detected value. The output device outputs the determined growth state and the like.

[0010]

1 is a functional block diagram of a crystal growth monitoring apparatus according to the present invention. The crystal growth monitoring device 10 includes an input device 12 that captures image data G by imaging a growing crystal,
Parameter extracting means 14 for extracting the parameter Xn for determining the growth state of the crystal from the image data G, detection value storage means 16 for storing the parameter Xn as the detection value Xn (t), and the crystal growing normally. The reference value storage means 18 in which the reference value SXn (t) consisting of the above parameters and the growth state SYN (t) corresponding to the reference value SXn (t) are stored in advance,
Detection value Xn (t) is compared with detection value Xn (t) and reference value SXn (t)
Determination means 20 for determining the growth state Yn (t) corresponding to
The output device 22 outputs at least the growth state Yn (t).

The parameter Xn is the total brightness X _{11 of} the crystal and its background, the brightness of the background of the crystal.
X ₂₁ , crystal size X ₃₁ , crystal size variation
X ₃₂ , crystal shape X ₄₁ , crystal shape type X ₄₂₁ , X ₄₂₂ …
There is a ratio for each, crystal density X _51, etc. The parameters and their extraction method will be described later.

The detected value Xn (t) is a parameter value at time t in the manufacturing process. The reference value SXn (t) is a parameter value at the time t of the manufacturing process when the crystal grows normally, for example, the upper limit value SXn (t) max. And the lower limit value SXn (t) min. ing. The reference value SXn (t) is determined in consideration of empirical knowledge by obtaining the variation from the allowable crystal growth trajectory in the actual manufacturing process for each product type. The growth state SYN (t) is data such as normal if it is within the range of the reference value SXn (t) and abnormal if not. The parameter value at the time t is an average value of several samplings before and after the time t.
It may be a value obtained by sampling once. Reference value SXn (t)
Is not limited to the upper limit value and the lower limit value, and may be one numerical value or three or more numerical values. Growth state SYN (t)
Is not limited to normal and abnormal, and may be data such as whether or not it is in a certain state, quality ranking, and product type classification. The reference value SXn (t) may be a parameter value when the crystal grows abnormally.

FIG. 2 is an overall configuration diagram specifically showing one embodiment of the crystal growth monitoring apparatus according to the present invention. The same parts as those in FIG. Parameter extraction means 14, detected value storage means 16 and reference value storage means 1
8 and the determination means 20 are a control unit 3 including a computer.
Configure 0. Peripheral devices such as a keyboard 32 are connected to the control unit 30. The output device 22 is the printer 3
4, CRT 36, process control device 38 and the like.

The input device 12 includes a light projecting section 50 and a light receiving section 52.
Composed of and. The light projecting unit 50 is provided at the U-shaped light guide tube 56 having one end inserted in the crystal can 54, an optical fiber 58 inserted in the light guide tube 56, and the other end of the light guide tube 56. The LED 60 as a light source and a light projecting window 62 provided at one end of the light guide tube 56. Light receiving section 52
Is a protruding tube 64 partially inserted into the crystal can 54, a light receiving window 66 provided at the tip of the protruding tube 64 and facing the light projecting window 62, a CCD camera 68 as an image pickup device, and a CCD.
The housing 70 houses the camera 68. Cooling air is constantly flowing in the housing 70.

The light projecting window 62 and the light receiving window 66 are immersed in the under white 72. 0.5 m between the light projecting window 62 and the light receiving window 66
m-5.0 mm, and sugar crystals pass through. LED
The light of 60 is applied to the crystal from the light projecting window 62 through the optical fiber 58 and enters the light receiving window 66. Therefore, the CCD camera 68 obtains an image of the growing crystal. The shutter speed of the CCD camera 68 is 1/100
It is 0 second to 1/4000 second. CC of CCD camera 68
Since the D element is made of silicon, the absorption edge 110
It has a wide range of spectral sensitivity characteristics from 0 nm to the ultraviolet region.

FIG. 3 is a flow chart showing the operation of one embodiment of the crystal growth monitoring apparatus according to the present invention. The operation of the crystal growth monitoring apparatus 10 will be described below with reference to this figure and FIG. However, the reference value SXn (t) is assumed to be given by the upper limit value SXn (t) max. And the lower limit value SXn (t) min. In addition,
This flow chart is a schematic and is only an example. An image of the growing crystal is picked up by the CCD camera 68 and used as image data G (step 101). The image data G is processed by the parameter extracting means 14, and the parameter Xn for determining the growth state of the crystal is extracted from the image data G (step 102). Parameter Xn
Is stored as the detected value Xn (t) in the detected value storage means 16 (step 103). The determination means 20 uses the detected value Xn (t)
And the reference value SXn (t). That is, the detected value Xn (t)
Is checked whether it is within the range of the reference value SXn (t) (step 104). If it is within the range, the growth state Yn (t) =
It is determined to be "normal" (step 105). If it is out of the range, it is determined that the growth state Yn (t) = "abnormal" (step 106). The growth state Yn (t) thus obtained is output to the output device 22 (step 107). Then, it is checked whether the manufacturing process is completed (step 10
8). This is “finished because a predetermined amount of crystals has been manufactured” and “finished because an abnormality has occurred in the manufacturing process” with a parameter indicating the progress (for example, density X ₅₁ described later).
It is a check as to whether or not it has been judged as equal. If it is determined to be "end", the process ends. Otherwise,
The sampling time Δt is added to the time t of the manufacturing process (step 109) and the process returns to step 101. The sampling time Δt is, for example, 1 second to 10 seconds, and all steps may be constant or may be coarse and fine.

Next, the parameters and the method of extracting the parameters will be described. FIG. 4 is an example of an image of the lower white 72. crystal
The background of C1 ... is the solution 74. That is, white bottom 7
2 is divided into crystals C1 ... And solution 74.

The overall brightness of the crystal and its background
X ₁₁ is obtained by averaging the brightness of all pixels of the CCD element. Brightness X ₁₁ is 0-25 depending on its brightness
Take any one of the five numbers. As the crystal C1 grows thicker and blacker as it grows, the brightness X ₁₁ decreases. On the other hand, the rheometer value (apparent viscosity) is 72 below white.
As the proportion of crystals C1 ...
The brightness X ₁₁ shows a correlation with the rheometer value.

FIG. 5 is a graph showing an example of a temporal change in the overall brightness X ₁₁ . The lapse of time t corresponds to the progress of the manufacturing process. Although the ratio of the crystals C1 ... in the under-white 72 changes with each intermittent operation (supplying water or sugar solution by dividing into fixed amounts), the crystals C1 ...
You can see that the growth of. FIG. 6 is a graph showing an example of the change over time of the reference value of the overall brightness X ₁₁ . Detection value X
₁₁ (t) is within the reference value SX ₁₁ (t), that is, the upper limit value SX ₁₁ (t) ma
If it is between x. and the lower limit value SX ₁₁ (t) min., it is judged as normal, and if not, it is judged as abnormal.

The background brightness X ₂₁ of the crystal is the brightness of the solution 74 and is obtained by the following image processing. CC
The brightness of each pixel of the D element is binarized into black and white by an appropriate threshold value. Then, the black portion (outline of the crystal C1 ...) Is expanded / contracted to make the entire crystal C1 ... Black portion, and the brightness of each pixel of the remaining white portion (solution 74) is averaged. The brightness X ₂₁ of the solution 74 becomes darker as the concentration of the solution 74 increases and becomes brighter as the concentration of the solution 74 decreases. That is, the brightness X ₂₁ is inversely proportional to the concentration of the solution 74.

FIG. 7 is a graph showing an example of the temporal change of the background brightness X ₂₁ . The lapse of time t corresponds to the progress of the manufacturing process. Although the concentration of the solution 74 decreases with each intermittent operation, the solution 74 and the under white 72
It can be seen that the concentration of is increased and the growth of the crystals C1 ...
FIG. 7 is a graph showing an example of the change over time of the reference value of the background brightness X ₂₁ . The detected value X ₂₁ (t) is within the reference value SX ₂₁ (t),
That is, if it is between the upper limit value SX ₂₁ (t) max. And the lower limit value SX ₂₁ (t) min.

The crystal size X ₃₁ is obtained by averaging all the numbers of the diameter lengths of the black portions (crystals C1 ...) Obtained by the above-described method in a certain direction.

FIG. 9 is a graph showing an example of the change over time of the crystal size X ₃₁ . The lapse of time t corresponds to the progress of the manufacturing process. It can be seen that the crystals C1 ... FIG. 10 is a graph showing an example of the change over time of the reference value of the crystal size X ₃₁ . Detection value X
₃₁ (t) is within the reference value SX ₃₁ (t), that is, the upper limit value SX ₃₁ (t) ma
If it is between x. and the lower limit value SX ₃₁ (t) min., it is judged as normal, and if not, it is judged as abnormal. Since the crystal size X ₃₁ can be recognized, the occurrence of force grain F 1 as shown in FIG. 4 can be immediately determined. The end of the manufacturing process can be determined by recognizing that the crystal size X ₃₁ has become a certain size. It is also possible to recognize the color or concentration of the crystal, and it is possible to judge the color change or the like of the crystal.

The crystal size variation X ₃₂ is obtained as the standard deviation of the crystal size X ₃₁ .

FIG. 11 is a graph showing an example of time variation of crystal size variation X ₃₂ . The lapse of time t corresponds to the progress of the manufacturing process. The variation in the size of the crystals C1 ... With the passage of time t can be seen. FIG. 12 is a graph showing an example of the change over time in the reference value of the crystal size variation X ₃₂ . If the detected value X ₃₂ (t) is within the reference value SX ₃₂ (t), that is, below the upper limit value SX ₃₁ (t) max., It is determined as normal, and if not, it is determined as abnormal. Further, it is determined in quality due to variations X _{3 2} degree of at the end of the manufacturing process. The smaller the variation X _{32, the} higher the quality.

FIG. 13 is an explanatory view showing the crystal shape X ₄₁ and the rating of the shape. If the shape is normal, the score is 1 point, and the higher the abnormality, the higher the score, and the maximum is 10. The crystals C1 ... Are recognized by the above-described method, the template for each shape is set according to the size X ₃₁ of the crystal C1 ..., and template matching is performed to classify each crystal C1. The shape thus recognized is given a score according to each shape as shown in FIG. 13, and the average value of these is the value of the shape X ₄₁ .

FIG. 14 is a graph showing an example of the change over time of the crystal shape X ₄₁ . The lapse of time t corresponds to the progress of the manufacturing process. The degree of normality of the shape of the crystals C1 ... The detected value X ₄₁ (t) is the reference value SX ₄₁ (t)
In other words, the upper limit SX ₄₁ (t) max. And the lower limit SX ₃₁ (t) min.
If it is between 1 and 1, it is determined to be normal, and if not, it is determined to be abnormal.
Further, the quality can be judged by the degree of the shape X ₄₁ at the end of the manufacturing process. The smaller the shape X _{41, the} higher the quality.

FIGS. 15 to 18 are graphs showing an example of changes with time of the ratios X ₄₂₁ , X ₄₂₂ , X ₄₂₃ , and X _{424 for} respective crystal shape types. X ₄₂₁ , X ₄₂₂ , X ₄₂₃ , and X ₄₂₄ correspond to the shapes with scores 1, 2, 3, and 10, respectively. The lapse of time t corresponds to the progress of the manufacturing process. Detection value X ₄₂₁ (t), X ₄₂₂ (t)
, X ₄₂₃ (t), X ₄₂₄ (t) are the reference values SX ₄₂₁ (t), SX
If it is within ₄₂₂ (t), SX ₄₂₃ (t), or SX ₄₂₄ (t), it is determined as normal, and if not, it is determined as abnormal.

The crystal density X ₅₁ is the ratio of the crystals C1, C2, ... To the entire area of the white bottom 72 shown in FIG. Crystal C1
The area of ... Is obtained by obtaining the black portion (crystal C1 ...) By the method described above and summing those areas.

FIG. 19 is a graph showing an example of the change over time in the crystal density X ₅₁ . The lapse of time t corresponds to the progress of the manufacturing process. It can be seen that the area occupied by the crystals C1 ... Increases with the lapse of time t, and the growth proceeds. The density X ₅₁ finally indicates the production volume. FIG. 20 is a graph showing an example of the change over time of the reference value of the crystal density X ₅₁ . Detection value X ₅₁ (t)
Is within the standard value SX ₅₁ (t), that is, between the upper limit value SX ₅₁ (t) max. And the lower limit value SX ₅₁ (t) min. Since it calculates the total amount of readily crystallized from density X ₅₁ of the crystal, by density X ₅₁ of the crystal has reached the a predetermined amount, it can determine the end of the manufacturing process.

Next, an example of a method of monitoring a crystal growth by extracting a plurality of parameters will be described.

Table 1 shows important parameters in the concentration process.
Shown in. The sugar solution is sucked into the crystal can, and the concentration is continued to a supersaturated concentration by vacuum heating concentration. At this stage, no crystals are formed, so the brightness X ₁₁ , X _21, that is, the concentration of the solution is detected to judge the progress. If there is abnormality in the brightness X _11, X _21, occurrence of the force grain, abnormality such as contamination of solid impurities is determined. Further, abnormalities such as generation of force grains and mixing of solid impurities are also judged by the crystal size X ₃₁ .

Table 2 shows important parameters immediately after the crystallization and immediately thereafter. A seed crystal is put into a solution having a supersaturated concentration, and this is used as a nucleus to grow a crystal. This is called crystal. In this case, the occurrence, normality, and abnormality of crystallites are determined based on the crystal size X ₃₁ , the crystal size variation X _{32, and the} like. Immediately after the crystallization, the concentration of the solution decreases due to crystal growth, but the concentration gradually increases and the concentration of the solution increases again. In addition, since the crystal nuclei adhere to each other immediately after the crystallization,
Add water as judged by the brightness X ₁₁ , X ₂₁ , crystal size X ₃₁ , variation in crystal size X _32, etc.

Table 2 shows important parameters in the aligning process.
Shown in. Since there is an upper limit to the concentration of the solution in which force grain does not occur, the average supersaturated concentration is maintained by intermittent operation (supplying water or sugar solution by dividing it into fixed amounts). When force grain occurs because force grain is smaller than the normal crystal, especially crystal size X ₃₁
Immediately determined by variation in crystal size X _32, etc., an operation of adding water (diffusion) is performed in order to crush the sprouting of force grains. The timing of this difference water is also determined by parameters such as brightness X ₁₁ and X ₂₁ indicating the concentration of the solution.

Table 2 shows the important parameters at and immediately after the conversion. In the third difference of water, add a large amount of water to completely dissolve the force grains and concentrate again. This is called conversion. The concentration of the solution, the force grain, the solid impurities, and the like are determined by the brightness X ₁₁ , X ₂₁ , the crystal size X ₃₁ , the crystal size variation X _{32, and the} like.

Table 3 shows important parameters at the end of the crystal growth process and the manufacturing process. Crystal density from around conversion
As X ₅₁ increases, the upper limit of the solution concentration at which no force grain is generated rises. This is because the crystal surface area increases as the crystal grows and the sprouting of force grains is taken into the crystal surface. Therefore, the crystal growth progresses rapidly, the volume in the crystal can increases, and the crystal size X ₃₁ , the crystal density X _51, etc. reach a predetermined amount, and the process ends. At this stage, the crystal size X ₃₁ , the crystal size variation X ₃₂ , the crystal shape X ₄₁ , and the crystal shape type are used to judge the crystal quality.
Parameters such as the ratio for each X ₄₂₁ , X ₄₂₂ ... Are important.

[Table 1]

[Table 2]

[Table 3]

The image of FIG. 4 and the graphs of FIGS. 5 to 20 (excluding FIG. 13) are one or a plurality of CRTs 3 shown in FIG.
Displayed by 6.

In the above embodiment, sugar is used as an example,
The crystal growth monitoring device according to the present invention can be used for anything produced by precipitating crystals in a solution, for example, seasonings such as L-glutamate monosodium and aspirin, ascorbic acid and the like. It can also be suitably used for medicines.

[0039]

According to the crystal growth monitoring apparatus of the present invention, since the crystal growth state is directly determined by the parameters extracted from the crystal image data, the number and size of crystals, the occurrence of force grains, Abnormalities in crystal shape can be detected immediately and accurately, and progress, quality, abnormalities and other states can be accurately determined.

[Brief description of drawings]

FIG. 1 is a functional block diagram of a crystal growth monitoring device according to the present invention.

FIG. 2 is an overall configuration diagram specifically showing one embodiment of the crystal growth monitoring device according to the present invention.

FIG. 3 is a flowchart showing the operation of an embodiment of the crystal growth monitoring device according to the present invention.

FIG. 4 is an explanatory diagram showing an image below white in an embodiment of the crystal growth monitoring apparatus according to the present invention.

FIG. 5 is a graph showing an example of changes over time in parameters of the crystal growth monitoring apparatus according to the present invention.

FIG. 6 is a graph showing an example of a change over time in parameters of the crystal growth monitoring apparatus according to the present invention.

FIG. 7 is a graph showing an example of temporal changes in parameters of the crystal growth monitoring device according to the present invention.

FIG. 8 is a graph showing an example of a change over time in parameters of the crystal growth monitoring apparatus according to the present invention.

FIG. 9 is a graph showing an example of the change over time in the parameters of the crystal growth monitoring device according to the present invention.

FIG. 10 is a graph showing an example of a change over time in parameters of the crystal growth monitoring apparatus according to the present invention.

FIG. 11 is a graph showing an example of a change over time in parameters of the crystal growth monitoring apparatus according to the present invention.

FIG. 12 is a graph showing an example of a change over time in parameters of the crystal growth monitoring apparatus according to the present invention.

FIG. 13 is a graph showing an example of parameters of the crystal growth monitoring apparatus according to the present invention.

FIG. 14 is a graph showing an example of a change over time in parameters of the crystal growth monitoring apparatus according to the present invention.

FIG. 15 is a graph showing an example of a change with time of parameters of the crystal growth monitoring apparatus according to the present invention.

FIG. 16 is a graph showing an example of a change over time in parameters of the crystal growth monitoring apparatus according to the present invention.

FIG. 17 is a graph showing an example of a change over time in parameters of the crystal growth monitoring apparatus according to the present invention.

FIG. 18 is a graph showing an example of the change over time in the parameters of the crystal growth monitoring apparatus according to the present invention.

FIG. 19 is a graph showing an example of a change with time of parameters of the crystal growth monitoring apparatus according to the present invention.

FIG. 20 is a graph showing an example of a change over time in parameters of the crystal growth monitoring apparatus according to the present invention.

[Explanation of symbols]

10 ... Crystal growth monitoring device 12 ... Input device 14 ... Parameter extraction means 16 ... Detected value storage means 18 ... Reference value storage means 20 ... Judgment means 22 ... Output equipment

Claims (9)

[Claims] 1. A parameter extracting means for extracting a parameter for determining a crystal growth state from image data of the crystal, a detection value storing means for storing the extracted parameter as a detection value, and the crystal has grown. In the case of reference value storage means for storing in advance a reference value consisting of the above parameters and a growth state corresponding to this reference value, and comparing the detected value with the reference value to determine the growth state corresponding to the detected value. And a crystal growth monitoring device. 2. An input device for imaging a growing crystal to obtain image data, a parameter extracting means for extracting a parameter for determining a growth state of the crystal from the image data, and the extracted parameter. Detected value storage means to store as a detected value, reference value storage means pre-stored reference value and growth state corresponding to the reference value consisting of the parameter when the crystal is normally grown, and the detected value A crystal growth monitoring apparatus comprising: a determination unit that compares the reference value with a growth state corresponding to the detected value; and an output device that outputs at least the determined growth state. 3. The crystal growth monitoring apparatus according to claim 1, wherein the parameter is the total brightness of the crystal and the background thereof. 4. The crystal growth monitoring device according to claim 1, wherein the parameter is the brightness of the background of the crystal. 5. The parameter is a crystal size.
Alternatively, the crystal growth monitoring device according to item 2. 6. The crystal growth monitoring apparatus according to claim 1 or 2, wherein the parameter is variation in crystal size. 7. The crystal growth monitoring device according to claim 1, wherein the parameter is the crystal shape. 8. The crystal growth monitoring apparatus according to claim 1 or 2, wherein the parameter is a ratio for each type of crystal shape. 9. The crystal growth monitoring device according to claim 1, wherein the parameter is the density of crystals.