JP2000060350A - Production of pearl - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce pearls shining beautifully in a specific hue in high yield. SOLUTION: A light source 61 such as a light emitting diode for irradiating pearl oysters during culture with light is installed and a monitoring means 71 such as a photodiodide for monitoring the intensity of the light for irradiating the pearl oysters is provided. The flashing of the light source 61 or the quantity of projected light or both are controlled on the basis of results of the monitoring with the monitoring means 71 so as to irradiate the pearl oysters with the light at a prescribed intensity according to a predetermined prescribed time schedule. The pearl oysters may be moved to a shallow place to provide a bright state or moved to a deep place to afford a dark state. Thereby, the pearl oysters during the culture can be irradiated with the light at the prescribed intensity according to the predetermined prescribed time schedule regardless of the day and night and independently of the weather and the irradiation can be stopped. As a result, pearls containing a laminated structure of nacreous layers created therein can be produced.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to pearls and a method for producing pearls.

[0002]

BACKGROUND OF THE INVENTION Pearls include natural products and cultured products, but most of the pearls offered on the market are pearl pearl cultured products. The cultivation of pearl oysters (pearl oysters) begins with the breeding of juvenile oysters, and when they grow into mother oysters, the pearl nucleus is "introduced". After that, in the process of being returned to the sea and cultured, the nacre itself "rolls" the surface of the pearl nucleus. This "rolling" creates spherical pearls, which are taken from the pearl oysters and shipped after being fried at the beach.

By the way, the pearls produced from pearl oysters generally shine white or cream-colored pearls (pearls). Pearls are also produced. Pearls with a particular shade,
In particular, pink pearl pearl pearls are difficult to obtain, so they tend to be expensive in general.

In order to artificially give a specific color to a pearl, for example, it is conceivable to give a special chemical substance to a cultured pearl oyster to color the nacre itself. It is also considered that the pearls produced by aquaculture are extracted from the pearl oysters and then colored with a certain chemical substance.

[0005]

However, in the artificially colored pearls as described above, the original shine inherent in the pearls is lost, and the value as a decorative article is significantly reduced. For this reason, attempts to artificially give a specific shade have been commercially unsuccessful to date.

Therefore, an object of the present invention is to provide a pearl production method capable of producing a pearl artificially having a specific color tone with good reproducibility without damaging the original shine of the pearl.

[0007]

[Means for Solving the Problems] The present invention provides a pearl that forms a pearl layer by culturing a pearl oyster containing a pearl nucleus in water and solidifying the secretion of the pearl oyster on the surface of the pearl nucleus. In the production method, the cultured pearl oysters are irradiated with light of a predetermined intensity for a period of time T1, and the subsequent period of time:
During T2, a unit layer having a predetermined layer thickness is formed by irradiating light having a sufficiently lower intensity than the predetermined intensity, or by substantially not irradiating the light, during a period of time T = T1 + T2. The pearl layer in which the unit layers are laminated is formed by repeating the switching of the intensity of light irradiation periodically at a cycle of time: T.

According to the present invention, a thick first layer having a low refractive index is formed during the irradiation time of light of a predetermined intensity (high intensity): T1, and a sufficiently low intensity of light is irradiated, or Alternatively, a thin second layer having a high refractive index is formed during the time T2 when light is not substantially irradiated, and the first and second layers form a unit layer of the nacre. Then, since the formation of the unit layer is repeated according to the periodic change of the intensity of the irradiated light, the nacre layer in which the unit layers having a predetermined layer thickness are laminated is formed. Therefore, the pearl layer of the produced pearls has a different refractive index for a given visible light from the inner side to the outer side, so that when the white light enters the pearl layer, the visible light preferably interferes. , Will have a particular hue. At this time, since no special substance is artificially introduced into the nacre, the unique beautiful shine inherent in pearl is not lost at all.

In the method for producing pearls according to the present invention, a unit layer having a layer thickness substantially equal to a predetermined half wavelength of visible light may be formed during the time T. By doing so, the refractive index of the nacre for the predetermined visible light will be different from the inner side to the outer side at a cycle equivalent to a half wavelength of the predetermined visible light, so that white light is incident on the nacre. Then, the above-mentioned predetermined visible light preferably interferes with each other, and has a predetermined shade of visible light.

Further, the present invention provides a method for producing pearls, wherein a pearl oyster containing a pearl nucleus is cultured in water, and the secretion of the pearl oyster is solidified on the surface of the pearl nucleus to form a pearl layer. A light source that irradiates the inner pearl oyster with light is installed, and a monitor means that monitors the intensity of the light that irradiates the pearl oyster is installed, and the pearl oyster has a predetermined intensity according to a predetermined time schedule. It is characterized in that the blinking of the light source and / or the amount of projected light is controlled based on the monitoring result of the monitoring means so that the above light is emitted.

According to the present invention, regardless of whether it is day or night, and regardless of the weather, the pearl oysters being cultivated are irradiated with light of a predetermined intensity according to a predetermined time schedule, and the pearl oysters are irradiated. As a result, the pearls having the desired laminated structure of the nacre can be produced.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Prior to the description of the embodiments, the principle of the present invention will be described with reference to FIGS. Figure 1 is a cross-sectional view of pearls produced from cultured pearl oysters (especially pearl oysters).
FIG. 2 is a schematic cross-sectional view of a nacre for explaining a mechanism of pearl glittering.

As shown in FIG. 1, a pearl produced by pearl oyster culture has a pearl nucleus 1 at the center, and a pearl layer 2 containing calcium as a main component is formed on the outside thereof. More specifically, the nacre 2 contains about 5% of a hard protein (conchiolin), but structurally an extremely thin interlayer substrate (conchiolin film) and a large number of thin plate-like crystals (aragonite-type carbonic acid). Calcium crystals) form a layered structure in which they are alternately stacked. The size of the thin plate crystal is about 2 to 8 μm, and the thickness is about 0.3 to 0.6 μm (Akira Machii, Pearl Story). The present inventor has made a process of forming the pearl layer 2 constituting such a pearl,
By studying the mechanism by which the unique brilliance occurs, we obtained the knowledge that the hue can be freely controlled.

A pearl oyster (pearl pearl oyster) that is being cultured wraps a pearl layer 2 around a pearl nucleus 1 in the process of inhabiting in the sea. The winding speed, that is, the formation rate of the pearl layer 2 is It becomes faster when exposed to light. Specifically, the forming speed is fast in a bright environment and slow in a dark environment. The volume density and light refractive index of the pearl layer 2 formed by solidifying the secretions of pearl oysters are low and low in a bright environment, and high and low in a dark environment.

The rate of nacre formation in cultured pearl oysters is
It varies considerably depending on the health and nutritional status of the pearl oysters, especially the intake of calcium etc. from seawater. In particular, it varies greatly depending on the season: 60 microns / month in September, 1
40 micron / month in October, 15 micron / month in November
Data of 5 microns / month are reported in the month and December. Therefore, from the early autumn to the late autumn, the thickness of the pearl layer 2 formed per day is about 0.5 to 2 μm, which is thick on a sunny day and thin on a cloudy or rainy day.
Then, the formation of the pearl layer 2 almost stops at night, and the layer having a high refractive index is formed extremely thin on the thick layer having a low refractive index formed in the daytime.

FIG. 2 schematically shows this, in which a thick first layer 21 having a low refractive index and a second thin layer 22 having a high refractive index are periodically repeated, that is, the first layer 21. A plurality of unit layers 20 each including the second layer 22 are stacked to form the pearl layer 2. Figuratively speaking, the nacreous layer 2 in which layers 21 and 22 having different densities are periodically laminated is formed like a tree ring appearing on a tree stump. Therefore, when white light is incident on the pearl layer 2, reflection occurs at the interface between the unit layers 20 and light interference occurs. In addition to the reflection, absorption and scattering of light by the nacre itself and the reflection, absorption and scattering of light by the substances contained in the nacre, the above-mentioned interference light plays an important role in the beautiful shine of pearls.

Especially, compared with the nacre formed in summer,
The nacre formed in the late autumn when the water temperature drops from 20 ° C to 12 ° C has large and regularly-overlapped calcium carbonate crystals, and therefore interference is more remarkable than light scattering, and brightness is increased. Therefore, pearl oysters are fried at the farm generally in late autumn and early winter.

By the way, the interference of the reflected light by the interference film is
It is strengthened when the film thickness is half the wavelength of light, or an odd multiple thereof, and weakened when it is an even multiple of the half wavelength. If expressed by a mathematical expression, the thickness of the interference film is D and the wavelength of light is λ, and D = (2n + 1) λ / 2 (1) (where n = 0,
1, 2, 3, ...), the hue of the wavelength λ appears strongly. Therefore,
For example, with red light having a wavelength of 0.6 micron, the refractive index of the nacre is 0.3 micron, 0.9 micron, 1.5
Assuming that they are regularly repeated in the micron cycle, pearls will have a beautiful pink glow.

However, in the pearls extracted from the cultured pearl oysters, the pearl layer 2 has a repeating structure of refractive index with a constant cycle on average, but the repeating cycle differs depending on the weather at the time of stacking. For this reason, normally, only visible light of a specific wavelength is not strengthened by interference, but interference is generated by visible light of all wavelengths, and as a result, the pearl shines almost white.

Therefore, the present inventor controls the laminated structure of the pearl layer 2 by irradiating the pearl oysters in culture with light of which intensity varies greatly at a constant cycle, and enhances the specific visible light by interference, thereby identifying I decided to give it a shade. Here, the thickness of each unit layer 20 of the pearl layer 2 is, in theory, an odd multiple (1) of a half wavelength of light corresponding to a desired color shade.
2 times, 3 times, 5 times ...), but it is difficult to control the growth of the pearl layer 2 only by light irradiation so that the thickness becomes, for example, 3 times the half wavelength of visible light. . That is, the formation speed of the nacre 2 slightly varies depending on the water temperature, nutritional state, time zone, and other environment of the culture area even under the same light irradiation condition. Therefore, the larger the layer thickness, the thicker each unit layer 20 is. The difference between is large. Therefore, when the layer thickness is three times the half-wavelength or more, it becomes difficult to selectively interfere only the light of a specific color. It was decided to stack in a cycle equivalent to.

By the way, the first layer 21 formed in a bright environment has a constant thickness and a low refractive index, and the second layer 22 formed in a dark environment is thin and has a high refractive index. Conventionally, the thickness of the unit layer 20 is different for each layer, but in the present invention, the thickness of the unit layer 20 is about 0.3 μm for the pearl which gives a red tint, and is 0. Pearls with a blue hue of about 25 microns are about 0.2 microns in size and are almost uniform.

The pearls according to the present invention not only have a specific shade, but also have a beautiful shine inherent in pearls. That is, as described above, the interference of light in the nacre layer 2 plays an important role in the peculiar brilliance of pearls, but this mechanism is not lost in the present invention. Therefore, it is possible to achieve a beautiful pearl shine that is completely different from the pearl colored with a chemical substance or the like.

In the pearl of the present invention, it is not necessary to form all of the pearl layer 2 with the unit layer 20 having a thickness equivalent to a half wavelength of visible light, and only a part of the layers is equivalent to a half wavelength of visible light. You may laminate with. For example, only a few layers of the outermost layer may be laminated at a cycle equivalent to a half wavelength of visible light, or only a few layers slightly inside the outermost layer may be laminated at a cycle equivalent to a half wavelength of visible light. To achieve unique color and brilliance. Further, the number of laminated layers may be two or more, but if the number of layers is large, the specific color tone becomes strong.

Next, an embodiment of the above-mentioned pearl production method will be described.

Culture of pearl oysters is carried out throughout the year,
As one embodiment, an environment is selected in which the nacreous layer 2 is thickened by about 100 microns in the three months (90 days) from the beginning of September to the beginning of December. 6 month growth thickness for September
If it is 0 micron, the forming thickness per day is 60/30
= 2 microns, and assuming that the time when it is brightened by sunlight is 11 hours per day, the formed thickness per hour is about 0.18 micron, and the formed thickness per 10 minutes is about 0.03 micron. . It should be noted that since the formation proceeds only slightly in the dark state at night, the formation thickness at night is assumed to be zero for convenience of description.

Therefore, in the first embodiment, the light irradiation for 70 minutes (bright state) and the dark state for 10 to 20 minutes are alternately repeated several times to several tens of times. Then, 0.03 × 7 = 0.21 micron nacre 2 in the bright state for 70 minutes
(Low refractive index first layer 21) is formed, and a very thin second layer 22 having a high refractive index is formed in a dark state for 10 to 20 minutes. In this case, the thickness of the unit layer 20 of the pearl layer 2 is 0.21.
Light having a wavelength of 0.42 μm is 0.42 μm.

Next, in the second embodiment, 90 minutes of light irradiation (bright state) and 10 to 20 minutes of dark state are alternately repeated several times to several tens of times. Then, a nacreous layer 2 (first layer 21 having a low refractive index) of 0.03 × 9 = 0.27 micron is formed in a bright state for 90 minutes, and a very high refractive index is very thin in a dark state for 10 to 20 minutes. The second layer 22 is formed. In this case, the thickness of the unit layer 20 of the pearl layer 2 is 0.27 μm, and the light whose half wavelength is equal to this is 0.2.
It is 54 micron green light.

Further, in the third embodiment, the light irradiation for 110 minutes (bright state) and the dark state for 10 to 20 minutes are alternately repeated several times to several tens of times. Then, a nacreous layer 2 (first layer 21 having a low refractive index) of 0.03 × 11 = 0.33 micron is formed in a bright state for 110 minutes, and an extremely thin high refractive index is formed in a dark state for 10 to 20 minutes. The second layer 22 is formed. In this case, the thickness of the unit layer 20 of the pearl layer 2 is 0.33.
Light having a wavelength of 0.66 micron, which is equivalent to a half wavelength, is red light having a wavelength of 0.66 micron.

In the above embodiment, the repetition of the bright state and the dark state can be realized by periodically changing the water depth of the pearl oyster in the daytime environment. That is, the depth of water is 4, 5
A shallow field of m or less produces a bright state, and a deep field of 10 m or more produces a dark state. Further, a lamp may be installed in a nighttime environment and may be caused to blink periodically. If such night lighting equipment is also used, the growth of the nacre 2 is promoted.

Next, an automatic pearl production apparatus capable of controlling the formation of a pearl layer by using artificial lighting equipment and a pearl production method applied here will be described. FIG. 3 is a schematic diagram showing the configuration.

The aquaculture raft 3 floats above the sea by a float 31, and a vertical drive device 40 is installed on the aquaculture raft 3. Two suspending ropes 41 that can be wound and unwound by the device 40 extend from the vertical drive device 40 into the sea. The aquaculture cage 5 for the hanging rope 41
The light source 61 connected to the power supply device 60 on the aquaculture raft 3 is installed in the vicinity of the position where the aquaculture cage 5 is moved to the uppermost position. Has been done. An optical sensor 71 is fixed to the upper surface of the aquaculture raft 3, and the optical sensor 71 is connected to a control box 70 on the aquaculture raft 3 via a signal line 72. A reel 73 is fixed to the control box 70, and the signal line 72 is wound or unwound according to the vertical movement of the aquaculture cage 5.

Here, the optical sensor 71 monitors the amount of irradiation light to the aquaculture cage 5, and is composed of, for example, a photodiode. Further, the vertical drive device 40 is adapted to detect the length of the suspension rope 41 that is extended, and the detected value is sent to the control box 70 as a culture cage position signal at any time. The control box 70 has a built-in microcomputer, and based on a pre-stored program, a monitor signal from the optical sensor 71, and an aquaculture cage position signal from the vertical drive unit 40, the operation of the vertical drive unit 40 and the lighting of the light source 61, Control the turning off. Hereinafter, this will be specifically described.

For example, 70 minutes in a bright state and 20 in a dark state.
It is assumed that the program is set so that the cycle of minutes is repeated 20 times in total. Then, assuming that the control box 70 is activated at 5 o'clock in the morning before sunrise, the microcomputer determines, based on the monitor signal from the optical sensor 71, whether or not the aquaculture cage 5 is irradiated with light having a light amount equal to or higher than a predetermined level. Naturally, since the light amount is insufficient because it is before sunrise, the microcomputer issues a command to wind the hanging rope 41 to the vertical drive device 40. As a result, the aquaculture cage 5 moves from the deep area to the shallow area, but even after the aquaculture cage 5 reaches the uppermost position, the monitor signal from the optical sensor 71 is in a state of insufficient light quantity because it is before sunrise. Therefore, the microcomputer issues a command to the power supply device 60 to turn on the light source 61. This artificial lighting brings the aquaculture cage 5 into a bright state and promotes the formation of the nacre.

At 6:10 after 70 minutes have passed, the control is switched from the bright state to the dark state, and the light source 61 is turned off by the command from the microcomputer. However, the soft light of the morning shines under the sea, and this alone does not provide sufficient darkness. Therefore, the microcomputer issues a command to the up-and-down drive device 40 to let out the hanging rope 41. As the aquaculture basket 5 descends in the sea, the monitor light amount of the optical sensor 71 decreases, and when the aquaculture basket 5 falls below a predetermined level, the suspension rope 41 is commanded to be stopped. As a result, the aquaculture cage 5
Goes dark and begins to form a thin layer of high refractive index on the outermost layer of nacre. Since the sunlight in this time zone is still weak, the aquaculture cage 5 is located in a slightly shallow depth in the sea, and therefore the power consumption of the vertical drive device 40 is saved.

At 20:30, at 6:30, the control switches from the dark state to the bright state, the suspension rope 41 is wound up by the command of the microcomputer, and the aquaculture cage 5 moves toward the sea surface. Reach the top position. However, the morning light is still weak, and this alone is not enough bright light. Then, the light source 61 is turned on by the command from the microcomputer. This artificial auxiliary lighting brings the aquaculture cage 5 into a predetermined bright state and promotes the formation of the nacre. Thereafter, as the sun rises, the sea becomes brighter and the amount of light monitored by the sunlight sensor 71 exceeds a predetermined level. Then, the light source 61 is turned off by the command from the microcomputer, and the control of the amount of the nacre formed by only natural light is started. The nacre formed in this bright state has a low refractive index but is thick.

At 70:40 after 70 minutes, the control is switched from the bright state to the dark state, and the light source 61 is turned off by the command from the microcomputer. However, the bright light of the morning shines in the sea, and this alone does not make it dark. Therefore, the microcomputer issues a command to the up-and-down drive device 40 to let out the hanging rope 41. As the aquaculture basket 5 descends in the sea, the monitor light amount of the optical sensor 71 decreases, and when the aquaculture basket 5 falls below a predetermined level, the suspension rope 41 is commanded to be stopped. As a result, the aquaculture cage 5
Goes dark and begins to form a thin layer of high refractive index on the outermost layer of nacre. In addition, since the sunlight in this time zone is quite strong, the aquaculture cage 5 will be located in a slightly deeper place in the sea.

By repeating the same process,
A multi-layered nacre is formed. In winter, the thickness of the nacre formed in one day may not reach half the wavelength of visible light.In such a case, light is turned on by turning on the light source in the morning and evening. The time is controlled to be longer than the daytime.

[0038]

As described above, according to the present invention, since the formation of the unit layer is repeated according to the periodical change in the intensity of the irradiated light, the pearl layer formed by laminating the unit layers having a predetermined layer thickness is formed. To be done. Therefore, the pearl layer of the produced pearls has a different refractive index for a given visible light from the inner side to the outer side, so that when the white light enters the pearl layer, the visible light preferably interferes. , Will have a particular hue.
At this time, since no special substance is artificially introduced into the nacre, the unique beautiful shine inherent in pearl is not lost at all.

Further, in the method for producing pearls according to the present invention, the pearl layer may have a refractive index with respect to a predetermined visible light that varies from the inner side to the outer side at a cycle equivalent to a half wavelength of the predetermined visible light. For example, when white light is incident on the nacre, the above-mentioned predetermined visible light interferes favorably with the predetermined visible light.

Further, according to the method for producing pearls of the present invention, the light source for irradiating the pearl oyster under cultivation with light is installed, and the monitor means for monitoring the intensity of the light irradiating the pearl oyster is installed. Then, so that the pearl oysters are irradiated with light of a predetermined intensity according to a predetermined time schedule,
Since the blinking of the light source and / or the projected light amount is controlled based on the monitoring result of the monitoring means, the predetermined time schedule is set for the pearl oyster under cultivation regardless of day or night and the weather. Since it is possible to irradiate light of a predetermined intensity and to stop the irradiation, there is an excellent effect that pearls having a desired laminated structure of nacre can be produced.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a cultured pearl.

FIG. 2 is a schematic sectional view illustrating the principle of pearl shining.

FIG. 3 is a diagram illustrating a method for culturing pearls according to an example.

[Explanation of Codes] 1 ... Pearl nucleus, 2 ... Pearl layer, 21 ... Low refractive index and thick first layer, 22 ... High refractive index and thin second layer, 3 ... Aquaculture raft, 31 ...
Float, 40 ... Vertical drive device, 41 ... Suspended rope, 5 ... Aquaculture cage, 60 ... Power supply device, 61 ... Light source, 70 ...
Control box, 71 ... Optical sensor, 72 ... Signal line.

Claims (3)

[Claims] 1. A method for producing pearls, wherein a pearl shell containing a pearl nucleus is cultured in water, and the secretion of the pearl shell is solidified on the surface of the pearl nucleus to form a pearl layer. The pearl oysters are irradiated with light of a predetermined intensity during a time T1 and are irradiated with light of a sufficiently lower intensity than the predetermined intensity during a subsequent time T2, or the light is substantially irradiated. By not irradiating, a unit layer having a predetermined layer thickness is formed during the time: T = T1 + T2, and the switching of the intensity of the light irradiation is periodically repeated at a cycle of the time: T to stack the unit layers. The method for producing pearls, wherein the pearl layer is formed. 2. The method for producing a pearl according to claim 1, wherein the unit layer having a layer thickness substantially equal to a predetermined half wavelength of visible light is formed during the time T. 3. A method for producing pearls, wherein a pearl oyster containing a pearl nucleus is cultured in water, and the secretion of the pearl oyster is solidified on the surface of the pearl nucleus to form a pearl layer. A light source that irradiates the pearl oyster with light is installed, and a monitor unit that monitors the intensity of light radiated to the pearl oyster is installed, and the pearl oyster has a predetermined intensity according to a predetermined time schedule. The method for producing pearls is characterized in that the blinking of the light source and / or the amount of projected light is controlled on the basis of the monitoring result of the monitoring means so that the above light is emitted.