JP6687259B2 - Light energy time sharing device - Google Patents

Description

  The present invention provides a light energy time-division distribution device, a plant factory, a building, a light energy time-division distribution method for distributing the light energy of concentrated sunlight or the light energy of an artificial light source such as a lamp in a time-division manner. More particularly, the present invention relates to a light energy time division distribution device having a structure for distributing incident light energy at high speed, a plant factory, a building, a light energy time division distribution method, and a rotation tube.

  Due to the recent tendency to prevent global warming, the need for using renewable energy is increasing more than ever. Above all, sunlight is often used for power generation using a solar power generation panel and a solar heat collector, or for hot water generation. In addition, sunlight has been applied for use in daylighting systems in buildings such as houses or offices.

  On the other hand, when cultivating a positive plant that requires strong light in a plant factory, the positive plant is irradiated with light such as sunlight or a high-intensity lamp. In order to save energy, the light from the sunlight or high-intensity lamp may be blinked in a pulsed manner at high speed or may be time-divided to distribute light. Further, Patent Documents 1 to 3 disclose that photosynthesis of a plant is accelerated when the plant is irradiated with light in pulses.

  In this way, in addition to buildings such as houses and offices, plant factories (including solar combined type, complete artificial light type), wards, educational facilities and other buildings, or for a wide range of other purposes and purposes, It is desired to develop a time-division distribution device for light energy and a time-division distribution method for light energy.

JP, 03-059610, A Japanese Patent Publication No. 05-019129 Japanese Patent Publication No. 62-006785 Japanese Patent No. 4280456

Plant Factory Research Institute, “Influence of pulsed light on photosynthetic rate of plants”, [online], August 17, 2014, [December 3, 2015 search], Internet <URL: http: // www .sasrc.jp / pulse.htm>

As described above, strong light such as sunlight or high-brightness artificial light (light with high photosynthetic photon flux density, hereinafter referred to as high PPFD light) blinks at high speed or is time-divided and distributed. Despite the desire for technology, such technology has not yet been established. Here, high photon flux density (high PPFD) means about one-tenth or more (≧ about 200 μmol / s) of about 2000 micromoles per square meter per second (unit: μmol / m ² / s), which corresponds to the maximum PPFD of natural light. m ² / s) PPFD light energy. In addition, the term "high speed" as used herein refers to a state in which the light blinking frequency is, for example, several tens of hertz or higher and light and dark are repeated, and a time width for distributing light is, for example, about 100 microseconds or less.

  For example, Patent Documents 1 to 3 disclose a structure of time division distribution by a light distribution function by a rotating tilted mirror and a physical switching function of a joint surface between an incident side optical fiber and an exit side optical fiber. However, since these structures are complicated, it is difficult to increase the speed. In addition, it is difficult to time-divisionally distribute high PPFD light because the light reflection surface is narrow.

  On the other hand, when the light source itself uses a light emitting diode (hereinafter, referred to as an LED) capable of blinking at high speed, light can be intentionally blinked at high speed. By using LEDs, it is possible to save energy and extend the life of plant factories. However, it is not possible to accelerate the photosynthesis of tomatoes, melons, and other positive plants that require strong light, using the blinking of LED light in a fully artificial light plant factory. The LED light source does not have sufficient brightness and PPFD for photosynthesis of positive plants.

  There is also a method to increase the number of LEDs per irradiation area to increase the brightness. However, it is necessary to take measures against the heat generated by the loss of electricity-light conversion of LEDs. In addition, a large amount of power is required to drive the light emission of many LEDs including this loss. For this reason, increasing the number of LEDs is not practical considering profitability.

  Temporarily, not only for accelerating photosynthesis but also for energy saving, heat generation and power consumption are problems in fluorescent lights including LEDs, sodium lamps, metal halide lamps and other artificial lights. As described above, due to the problems of heat generation and power consumption, the method using LEDs cannot sufficiently increase the brightness and PPFD.

  Generally, in a fully artificial light type plant factory, the cultivation of semi-negative plants and negative plants such as lettuce and spinach increases, and thus PPFD can be easily raised due to the trade-off between heat generation and power consumption. Because there is no.

Generally, natural sunlight is used to grow positive plants. If the sunlight is too strong, it is blocked. Even if the light is shielded to about 40%, the PPFD is about 1000 (unit: μmol / m ² / s). This is a PPFD that is at least four times as high as the irradiation from the LED light source for plant factories, which is generally used, from about 20 cm above the sky.

  Therefore, in the cultivation of positive plants, in order to perform high-speed blinking control of pulsed light emission, it is necessary to have a structure that blinks the high PPFD light such as sunlight or high-brightness artificial light at high speed or distributes it in time division. It However, even for plant factories and applications other than plant factories, at present, there is no technique for blinking high PPFD light at high speed or for time-sharing distribution. This is a challenge.

  Further, as another problem, as disclosed in Patent Document 1, there is a problem of heat generated on the light reflecting surface when the high PPFD light is time-divided and distributed.

  When a high PPFD light is applied to a narrow area on the reflection surface, the material forming the reflection surface may be deformed or burned by heat if the reflection surface does not have a function of exhausting heat. That is, when the high PPFD light condensed in a narrow range is reflected using, for example, a rotating tilt mirror or a polygon mirror, the light energy is converted into heat by the reflection loss of the material used for the reflecting surface. The converted heat causes deformation or burning of the material forming the reflecting surface.

  As a measure to prevent the influence of this heat generation, a cooling function such as air cooling or water cooling for the purpose of discharging heat is required. For example, the light energy obtained from the light concentrating function toward the sun in an area of 1 square meter on the ground surface in fine weather near 35 degrees north latitude is about 1 kilowatt second (= 1000 joules) at the maximum in all wavelength ranges. is there. It is assumed that the light energy collected with almost no loss is lost by about 2% on the reflecting surface, and that this loss energy is entirely converted to heat on the material side. Then, the thermal energy at this time is equivalent to about 20 watt seconds (= 20 joules).

  More specifically, in an aluminum cube having 5 cm on all sides, one surface having a reflectance of 98% is defined as a reflecting surface. Then, the entire surface is irradiated with light energy of about 1 kilowatt second. Then, if there is no wind around the aluminum cube and the temperature is about 20 ° C, 2% of the energy loss is generated. As a result, theoretically, the surface temperature of aluminum reaches 160 degrees Celsius or higher about 100 minutes after irradiation. When the temperature of aluminum rises 140 degrees, the volume expands by about 1%. Therefore, the reflecting surface is deformed, which also affects the light reflecting performance.

  As described above, when the high PPFD light is time-divided and distributed, the heat generated at the light reflection surface is a problem.

  Furthermore, another problem is that the structure for distributing the high PPFD light in a time division manner is complicated.

  Patent Document 1 discloses that a light guide path is mechanically switched by rotating a reflecting mirror, a light guiding rod used together with the reflecting mirror, or an optical fiber. However, as disclosed in Patent Document 1, as the number of time-divided distributions increases, the number of components increases. Therefore, the accuracy required for processing becomes high.

  Furthermore, as the speed of the time division is increased, the swinging of the rotating member becomes larger, so that it becomes necessary to increase the accuracy of the shaft machining. This makes it difficult to balance the arrangement and mass of the components. Further, processing accuracy and assembly accuracy of many members such as the cross-sectional shapes of the light guide path and the optical fiber are required.

  The present invention has been made in order to solve such a problem, in a device that time-divisionally distributes high PPFD light such as concentrated sunlight and lamps, suppresses the influence of heat generation on the reflecting surface. While simplifying the structure of the device, it is an object to provide a light energy time-division distribution device, a plant factory, a building, a light energy time-division distribution method, and a rotary cylinder, which are capable of time-division distribution of light energy at high speed. To do.

  A light energy time-sharing distribution device according to an embodiment is a rotary cylinder that has an outer peripheral surface and that rotates about a central axis as a rotation axis, and that reflects incident light that is incident from one direction in a first direction. A rotating cylinder having the outer peripheral surface including a reflecting surface and a second reflecting surface that reflects the incident light in a second direction different from the first direction, and the light reflected in the first direction in a predetermined space. A first reflected light guide path that guides the light in one illumination range, and a second reflected light guide path that guides the light reflected in the second direction to a second illumination range in a predetermined space different from the first illumination range. , And the cross-sectional shapes of the first reflecting surface and the second reflecting surface orthogonal to the rotation axis each include a predetermined part of a logarithmic spiral curve about the rotation axis.

  Moreover, the plant factory which concerns on one Embodiment uses the said light energy time division distribution apparatus.

  Furthermore, the building which concerns on one Embodiment uses the said light energy time division distribution apparatus.

  A light energy time-sharing distribution method according to an embodiment is a rotary cylinder that has an outer peripheral surface and rotates about a central axis as a rotation axis, and that reflects incident light incident from one direction in a first direction. A step of causing light to be incident from the one direction to a rotating cylinder having the outer peripheral surface including a reflective surface and a second reflective surface that reflects the incident light in a second direction different from the first direction; and in the first direction The reflected first reflected light is guided to a first illumination range in a predetermined space, and the second reflected light reflected in the second direction is changed to a second in a predetermined space different from the first illumination range. And a step of guiding light to an illumination range, wherein the cross-sectional shapes of the first reflecting surface and the second reflecting surface orthogonal to the rotation axis are each a predetermined part of a logarithmic spiral curve about the rotation axis. including.

  Further, the rotary cylinder according to one embodiment is a rotary cylinder that has an outer peripheral surface and rotates about a central axis as a rotation axis, and a first reflecting surface that reflects incident light incident from one direction in a first direction. And the outer peripheral surface including a second reflection surface that reflects the incident light in a second direction different from the first direction, and the cross-sectional shape of the first reflection surface and the second reflection surface orthogonal to the rotation axis is , Each containing a predetermined portion of a logarithmic spiral curve about the axis of rotation.

  According to one embodiment, while suppressing the influence of heat generation, the structure of the device is simplified, and the light energy time division distribution device capable of distributing the light energy at high speed in a time division manner, a plant factory, a building, a light energy time division device. A method for dividing and distributing and a rotating cylinder are provided.

It is a figure which illustrated the rotary cylinder for optical energy time division distribution which concerns on Embodiment 1, (a) is a perspective view, (b) and (c) are sectional drawings orthogonal to a rotating shaft. (A) is the figure which illustrated the incident light and reflected light with respect to the reflective surface which has the logarithmic spiral curve and cross-sectional shape which are logarithmic spiral curves based on Embodiment 1, and (b) and (c) shows It is a figure which illustrated a part of logarithmic spiral curve used for the reflective surface which concerns on the form 1 of FIG. (A) And (b) is sectional drawing which illustrated the rotary cylinder which concerns on the modification of Embodiment 1. As shown in FIG. It is the figure which illustrated the light energy time division distribution device concerning Embodiment 2. FIG. 8 is a diagram exemplifying transitions of light and darkness of an irradiation range by the light energy time division distribution device in the second embodiment. FIG. 9 is a diagram exemplifying elements for calculating received light energy and irradiation energy in an irradiation range in the light collector according to the second embodiment. FIG. 7 is a flowchart diagram illustrating a light energy time division distribution method using the light energy time division distribution device according to the second embodiment. FIG. 11 is a diagram illustrating a light energy time division distribution device according to a modification of the second embodiment. FIG. 9 is a diagram illustrating a light energy time division distribution device according to a third embodiment. It is the figure which illustrated the light energy time division distribution device concerning Embodiment 4.

(Embodiment 1)
Hereinafter, embodiments of the present invention will be described with reference to the drawings. The first embodiment relates to a rotary cylinder used for time division sharing of light energy. First, the rotary cylinder according to the first embodiment will be described with reference to FIGS.

  1A and 1B are views exemplifying a rotary cylinder for time division distribution of light energy according to Embodiment 1, where FIG. 1A is a perspective view, and FIGS. 1B and 1C are cross-sections orthogonal to a rotation axis. It is a figure. As shown in FIGS. 1A to 1C, the rotary cylinder 1 is a substantially cylindrical member. The shaft 2 is provided at a position corresponding to the central axis of the cylindrical shape. The shaft 2 is a member that extends linearly. The direction along the axis 2 is defined as the axial direction. The direction of rotation about the axis 2 is the direction of rotation.

  The outer peripheral surface 3 of the rotary cylinder 1 includes a plurality of reflecting surfaces 4, for example, a plurality of first reflecting surfaces 4a and a plurality of second reflecting surfaces 4b. The plurality of first reflecting surfaces 4a and the plurality of second reflecting surfaces 4b extend in the axial direction from one end in the axial direction of the rotary cylinder 1 to the other end. The 1st reflective surface 4a and the 2nd reflective surface 4b arrange the outer peripheral surface 3 by turns along the rotation direction. Therefore, the outer peripheral surface 3 has a striped pattern in which the first reflecting surfaces 4a and the second reflecting surfaces 4b elongated in the axial direction are alternately arranged along the outer circumference. The widths of the first reflecting surface 4a and the second reflecting surface 4b in the rotation direction are equal, for example. The first reflecting surface 4a and the second reflecting surface 4b are adjacent to each other in the rotation direction of the outer peripheral surface 3.

  For example, six first reflecting surfaces 4a are arranged at equal intervals in the rotation direction of the outer peripheral surface 3. Six second reflection surfaces 4b are arranged between the first reflection surfaces 4a arranged at equal intervals. In the cross section orthogonal to the axis 2, each reflecting surface 4 is arranged in a circular arc portion corresponding to an angle of 30 °.

  The plurality of spokes 5 are provided so as to extend radially from the shaft 2 to the inner peripheral surface of the rotary cylinder 1. The shaft 2 and the rotary cylinder 1 are fixed by a plurality of spokes 5. The shaft 2 is connected to a motor (not shown). By driving the motor, the rotary cylinder 1 can be rotated with the shaft 2 as the rotary shaft. Thus, the rotary cylinder 1 has the outer peripheral surface 3 and rotates about the central axis. The motor is connected to a power source via a controller, for example. Further, the controller controls the rotation of the motor while sensing the rotation of the rotary cylinder 1 by the sensor.

  Light 6, for example, linear light 6 extending in the axial direction is incident on the rotary cylinder 1. Incident light is incident on the outer peripheral surface 3 of the rotary cylinder 1 from one direction, for example, from above. The outer peripheral surface 3 rotates as the rotary cylinder 1 rotates. As a result, the light 6 incident on the outer peripheral surface 3 is alternately incident on the first reflecting surface 4a and the second reflecting surface 4b. The first reflecting surface 4a reflects the incident light 6 in the first direction 7a. The second reflecting surface 4b reflects the incident light 6 in the second direction 7b.

  As described above, the rotary cylinder 1 has an outer circumference including the first reflecting surface that reflects the incident light that is incident from one direction in the first direction and the second reflecting surface that reflects the incident light in the second direction different from the first direction. Has a face. The light 8a reflected by the first reflecting surface 4a travels in the first direction 7a. The light 8b reflected by the second reflecting surface 4b proceeds in the second direction 7b. The light 6 is preferably high PPFD light, but is not limited to this. LED light may be used. The cross-sectional shapes of the first reflecting surface 4a and the second reflecting surface 4b orthogonal to the rotation axis include a part of a logarithmic spiral curve centered on the rotation axis. The first reflecting surface 4a and the second reflecting surface 4b have a shape obtained by translating the cross-sectional shape in the axial direction.

  With reference to FIG. 2, a logarithmic spiral curve used for the first reflecting surface 4a and the second reflecting surface 4b according to the first embodiment will be described. FIG. 2A is a diagram exemplifying incident light and reflected light with respect to a reflecting surface having a logarithmic spiral curve and a cross-sectional shape of a logarithmic spiral curve according to the first embodiment, and (b) and (c) of FIG. FIG. 5 is a diagram illustrating a part of a logarithmic spiral curve used for the reflecting surface according to the first embodiment.

  The logarithmic spiral curve is also called an equiangular spiral curve, and is generally represented by the following mathematical formula (θ, b unit: radian).

  Here, the length r indicates the distance from the origin, the angle θ indicates the rotation angle of the spiral, and the coefficient a indicates the distance from the origin at the rotation angle θ = 0. As shown in FIG. 2, the curvature is constant at any point on the logarithmic spiral curve 9 depending on the angle b. The angle formed by the tangent lines t1 and t2 on the logarithmic spiral curve 9 and the lines R11 and R21 connecting the center O is always the angle b. Therefore, considering the incident / reflection of light on the logarithmic spiral curve 9, the angle formed by the incident light I11 and the perpendicular S1 of the tangent t1 and the angle formed by the reflected light I12 and the perpendicular S1 of the tangent t1, that is, the incident angle and The reflection angle φ is derived as follows (unit of φ: radian), and is always constant at any point on the logarithmic spiral curve 9.

  Note that, although the incident angle and the reflection angle from the outside of the logarithmic spiral curve 9 are shown in FIG. 2, the properties which are constant also in the incident angle and the reflection angle from the inside are the same.

  As shown in FIG. 2B, the cross-sectional shape of the first reflecting surface 4a orthogonal to the rotation axis includes a part 9a of a logarithmic spiral curve whose center is the rotation axis O. Further, as shown in FIG. 2C, the cross-sectional shape of the second reflection surface 4b orthogonal to the rotation axis includes a part 9b of a logarithmic spiral curve with the rotation axis as the center O. As described above, the cross-sectional shapes of the first reflection surface 4a and the second reflection surface 4b orthogonal to the rotation axis each include a part of a logarithmic spiral curve with the rotation axis as the center O.

  A function utilizing this property of the logarithmic spiral curve 9 is, for example, Patent Document 4. Patent Document 4 utilizes that the distances r1 and r2 of the line connecting the origins in FIG. 2 are different. Since the optical path length including the reflected light when the incident light is fixed and the logarithmic spiral curve side is rotated changes according to the rotation angle, the reflection of the logarithmic spiral curve is used to change the delay time of the optical path. Is the usage.

  In the present invention, the incident light is fixed, and the place where the light is incident on the line connecting the origin is the same, but for the purpose of reflecting in a plurality of directions using a plurality of logarithmic spiral curves of different curvatures, There is a clear difference in the usage of logarithmic spiral curves.

  As shown in FIGS. 1 (b) and 1 (c), when viewed from the axial direction, the outer peripheral surface 3 is divided into 12 parts each divided by 30 degrees with the axis 2 as the origin, and a part of the logarithmic spiral curve 9 is divided. Are arranged. In the 12 parts, adjacent parts are arranged such that the positive and negative of the curvature of the logarithmic spiral curve 9 are opposite to each other. That is, for example, the positive curvature portion of the logarithmic spiral curve 9 is the first reflecting surface 4a, and the negative curvature portion of the logarithmic spiral curve 9 is the second reflecting surface 4b. As described above, the logarithmic spiral curve of the cross-sectional shape of the second reflecting surface 4b has the positive and negative signs of the curvature of the logarithmic spiral curve of the cross-sectional shape of the first reflecting surface 4a.

  The cross-sectional shape of the outer peripheral surface 3 is formed with gentle peaks and valleys. The expression "gradual" means that the logarithmic spiral curve 5 has a relatively small curvature. When the curvature is small, the absolute value of the angle b is relatively close to 90 °. That is, it can be said that the incident / reflection angle φ is small.

  1B and 1C, when the light 6 is incident on the rotary cylinder 1 from one direction, for example, from above, the rotary cylinder 1 is rotating, and therefore the light 6 is reflected by the first reflecting surface 4a. And alternately enter the second reflecting surface 4b. While the light 6 is incident on the first reflecting surface 4a, it is reflected in the first direction 7a regardless of which portion of the first reflecting surface 4a is incident. Then, when the incidence of the light 6 is switched from the first reflecting surface 4a to the second reflecting surface 4b with the rotation of the rotary cylinder 1, the light 6 is reflected in the second direction 7b. While the light 6 is incident on the second reflecting surface 4b, it is reflected in the second direction 7b regardless of which part of the second reflecting surface 4b is incident.

  In this way, since the logarithmic spiral curve is used for the cross-sectional shapes of the first reflecting surface 4a and the second reflecting surface 4b, the light 6 incident on the outer peripheral surface 3 is not reflected by the first reflecting surface 4a or the second reflecting surface. It reflects in either the first direction 7a or the second direction 7b determined by the curvature of 4b. At this time, even if the luminous flux of the incident light has a certain width, the width of the angle difference between the incident and reflected angles φ when the curvature is relatively small is small. Therefore, the angular spread of the light 8 reflected by the reflection within the same reflection surface is small. Therefore, the light flux heads as a bundle in a certain fixed direction. Therefore, in accordance with the rotation angle of the rotary cylinder 1 that rotates at a constant speed, for example, it is distributed in a time-division manner so as to switch to two directions of the first direction 7a and the second direction 7b.

  In the example shown in FIGS. 1B and 1C, the first reflection surface 4a and the second reflection surface 4b are arranged so that each of them has six during one rotation. Therefore, every one rotation of the rotary cylinder 1, the distribution is performed 6 times in the two directions of the first direction 7a and the second direction 7b. At this time, for example, when the rotary cylinder 1 is viewed from the first direction 7a, it seems that the light flashes six times each time the rotary cylinder 1 makes one rotation. The mirror surfaces of the logarithmic spiral curve 9 are all divided at the same angle of 30 °. Therefore, when the rotary cylinder 1 is rotating at a constant speed, the light time or dark time in the light-dark cycle of light is equal. The duty ratio is 50%.

  According to the rotating cylinder 1 of the present embodiment, it is possible to time-distribute the high PPFD light such as sunlight. By changing the rotation speed of the rotary cylinder 1, the time division cycle can be controlled. Also, by increasing the rotation speed, it is possible to distribute high PPFD light at high speed in a time division manner.

  Further, since the rotary cylinder 1 is rotating at a high speed, the heat generated by the reflected light is dissipated. Therefore, the deformation and damage of the rotary cylinder 1 due to heat can be suppressed. Furthermore, since the time-divisional distribution can be performed simply by rotating the tubular member, the structure can be simplified.

(Modification)
Next, a modified example of the first embodiment will be described.
3A and 3B are cross-sectional views illustrating a rotary cylinder according to a modification of the first embodiment. As shown in FIG. 3A, instead of the first reflecting surface 4a and the second reflecting surface 4b of the rotary cylinder 1, a third reflecting surface 4c and a fourth reflecting surface 4d having different curvatures may be arranged. The third reflecting surface 4c and the fourth reflecting surface 4d reflect incident light in different directions.

  Further, as shown in FIG. 3B, in addition to the first reflecting surface 4a and the second reflecting surface 4b, a fifth reflecting surface 4e that reflects the incident light in the third direction and a sixth reflecting surface 4e that reflects the incident light in the fourth direction. The reflecting surface 4f may be added. That is, the outer peripheral surface 3 includes a fifth reflection surface and a sixth reflection surface that reflect incident light in a third direction and a fourth direction different from the first direction and the second direction, and the fifth reflection surface and the sixth reflection surface. The cross-sectional shape orthogonal to the rotation axis in may include a portion other than the part 9a and the part 9b of the logarithmic spiral curve centered on the rotation axis.

  According to this modification, in addition to the two directions of the first direction 7a and the second direction 7b, the light energy can be distributed at high speed in three or more directions, such as the third direction and the fourth direction. it can. Other effects are similar to those of the first embodiment.

(Embodiment 2)
Next, a second embodiment will be described. The second embodiment relates to a light energy time division distribution device. The configuration of the optical energy time-division distribution device according to the second embodiment will be described with reference to FIG. FIG. 4 is a diagram illustrating a light energy time division distribution device according to the second embodiment.

  As shown in FIG. 4, the light energy time division distribution device 20 includes a condenser 11, an incident light guide path 12, a rotary cylinder 1, light receiving portions 16a and 16b, a housing 17, reflected light guide paths 13a and 13b, and an illuminator 14a. And 14b.

  The light collector 11 collects the light 6, for example, sunlight. The condenser 11 converts the condensed light 6 into a line shape. The condenser 11 converts the condensed light 6 into continuous line-shaped light 6 or discrete line-shaped light 6. By making the incident light 6 linear, heat generation can be reduced. Further, by making the light 6 linear, it is possible to suppress the unevenness of the time-divided light.

  The incident light guide path 12 is, for example, an optical fiber cable. The incident light guide path 12 guides the light 6 condensed by the condenser 11 to the rotary cylinder 1. The incident light guide path 12 guides the linear light 6 converted by the condenser 11 to the rotary cylinder 1.

  The rotary cylinder 1 time-divisionally distributes the light 6 guided to the rotary cylinder 1 by the incident light guide path 12. The rotating cylinder 1 time-divisionally distributes the light 6 in the first direction 7a and the second direction 7b, as described in the first embodiment. The rotary cylinder 1 is arranged inside the housing 17.

  The reflected light guide paths 13a and 13b are, for example, optical fiber cables. Light receiving portions 16a and 16b are provided in the reflected light guide paths 13a and 13b. The reflected light guide paths 13a and 13b guide the light received by the light receiving portions 16a and 16b. The reflected light light guide path 13a (first reflected light light guide path) guides the light 8 reflected in the first direction 7a by the first reflection surface 4a of the rotary cylinder 1 to the illumination range 15a (first illumination range). The reflected light light guide path 13b (second reflected light light guide path) guides the light 8 reflected in the second direction 7b by the second reflection surface 4b of the rotary cylinder 1 to the illumination range 15b (second illumination range).

  The light guided to the illumination ranges 15a and 15b by the reflected light guide paths 13a and 13b is applied to the illumination ranges 15a and 15b via the illuminators 14a and 14b.

  In this way, the incident light is reflected in any direction (the first direction 7a and the second direction 7b) according to the reflecting surface 4 (the first reflecting surface 4a and the second reflecting surface 4b) of the rotary cylinder 1. . Therefore, the incident light is guided to either the reflected light guide path 13a-illuminator 14a-irradiation range 15a or the reflected light guide path 13b-illuminator 14b-irradiation range 15b. It is also possible to increase the number of reflecting surfaces having different curvatures and guide light in three or more directions.

  FIG. 5 is a diagram exemplifying a transition of brightness and darkness of an irradiation range by the light energy time division distribution device according to the second embodiment. As shown in FIG. 5, in the irradiation ranges 15a and 15b on the first direction 7a side and the second direction 7b side when the rotary cylinder 1 makes one rotation, "bright" and "dark" are alternately repeated. There is. The "bright" time is when the light is guided and illuminated, and the "dark" is when the light is not guided. In reality, the incident light 6 has a slight width. Therefore, when the rotating cylinder 1 rotates, when the incident light straddles the reflecting surface 4 different from each other, the switch is not clearly switched as shown in FIG. Here, for convenience, an ideal thin light 6 distribution state is shown.

  In FIG. 5, if the irradiation area on the reflecting surface 4 is the same, the photon flux density (PPFD) is at the same level. This is also the case when the rotary cylinder 1 performs time division distribution in two or more directions.

  The light energy time-division distribution device 20 of the present embodiment makes it possible to irradiate the area of the light receiving area or more with the light of the PPFD depending on conditions. On the contrary, by irradiating an area smaller than the light receiving area, it is possible to make the photon flux density higher than the original light and irradiate depending on the conditions. This will be described below.

  FIG. 6 is a diagram exemplifying elements for calculating the received light energy of the condenser and the irradiation energy of the irradiation range according to the second embodiment. As shown in FIG. 6, the light 6 received by the light receiving surface of the light collector 11 passes through the light collector 11, the rotary cylinder 1, the reflected light guide paths 13a and 13b, and the illuminators 14a and 14b to generate two irradiation ranges 15a. And 15b. The irradiation ranges 15a and 15b at this time repeat light and dark according to the rotation of the rotary cylinder 1. Let η1 and η2 be the transmission rates in consideration of the loss of light from the condenser 11 to the irradiation ranges 15a and 15b, respectively. The duty ratio of the time of irradiation to the irradiation ranges 15a and 15b is 50%.

  As shown in FIG. 6, the light receiving area in the condenser 11 is S0, the photon flux density is D0, the light receiving energy is P0, and the average light energy coefficient is A. The irradiation area in the irradiation range 15a is S1, the photon flux density is D1, the irradiation energy is P1, and the average light energy coefficient is A. The irradiation area in the irradiation range 15b is S2, the photon flux density is D2, the irradiation energy is P2, and the average light energy coefficient is A. At this time, the following formula is established.

  The coefficient A represents the average light energy per one photon flux depending on the wavelength band distribution of light. Here, it is assumed that the wavelength band distribution does not change from light reception to irradiation. The same average light energy coefficient A is used on the light receiving side and all the irradiation sides. At this time, as shown in FIG. 5, it is assumed that the time-sharing distribution is switched from 100% to 0%, or from 0% to 100%, in an ideal state. Then, P1 and P2 do not have energy simultaneously on the time axis. Note that η0 is the overall pass rate.

  Next, for the sake of simplicity, it is assumed for the sake of convenience that the irradiation areas are equal in the irradiation ranges 15a and 15b, and that the photon flux density and the passage rate when they are time-divisionally distributed in either one are equal in both light guide paths. To do. In that case, the following equation is derived.

When the equations (3) to (9) are applied and rearranged, the following three equations are finally obtained.

  Specifically, in the case of the purpose of making the photon flux density D0 of the light-receiving surface and the photon flux density D of the irradiation side the same photon flux density, for example, the passage rate η was any transmission rate of 50% or more. To do. Then, D0 = D, and 50% ≦ η ≦ 100%. Therefore, when the equation (13) is applied, the following is obtained.

  It can be seen that it is possible to irradiate a wide range of irradiation area (S1 + S2) over the original light receiving area S0. In the above description, the case of two distributions based on FIG. 1 was considered. Here, N is newly defined as a variable representing the number of light guide paths. The conditions of the expressions (10) to (12) are expanded to the number N of light guide paths, and the expressions (13) to (15) are generalized.

  Here, the area Sm of each irradiation surface and the suffix m of the light energy Pm indicate the light guide path number, and take an integer of 1 to N. In addition, here, for simplification of explanation, assuming that the time widths of time-divided light irradiation to the respective irradiation surfaces are all equal, the duty ratio on the time axis of the pulsed light irradiation surface is 1 / Let N. In addition, for the sake of convenience, the conditions of equations (10) to (12) are expanded so that the passage ratios η1 to ηN of all light guide paths are represented as η, and the irradiation surfaces S1 to SN are all equal. .

  The effects of the present embodiment will be described using equations (17) and (18). When it is desired to make the photon flux density D on the irradiation side equal to the photon flux density D0 on the light receiving surface for a certain purpose, the following equation may be applied to equation (17).

As a result, the following equation is obtained.

From this relational expression, it can be seen that time-division distribution can be made possible to the total irradiation area ΣSm of (N × η) times the light receiving area S0. In other words, it can be said that the light-receiving area S0 that is (1 / (N × η)) times the total irradiation-side area ΣSm is sufficient. Explaining the latter concretely, assuming that the photon flux density D on the irradiation side is equal to the photon flux density D0 on the light receiving surface, assuming a system with two distributions and a passage rate η of 60%, the total irradiation area ΣSm It can be seen that about 83.3% of the light receiving area S0 is sufficient.
On the other hand, when the irradiation side total area ΣSm and the light receiving area S0 are made equal, the following equation may be applied to the equation (17).

As a result, the following equation is obtained.

  From this relational expression, it can be seen that the irradiation-side photon flux density D that is (N × η) times the photon flux density D0 of the light-receiving surface can be obtained. The irradiation-side photon flux density D is the photon flux density in the time zone in which the light emitted as pulsed light by time division distribution is applied within one cycle. The irradiation-side photon flux density D indicates a peak photon flux density, not an average photon flux density.

  Thus, in equation (17), the ratio of the total area ΣSm on the irradiation side to the light receiving area S0 (ΣSm / S0), the ratio of the photon flux density D0 on the light receiving surface to the light quantum flux density D on the irradiation side (D0 / D), and By adjusting the relationship of the product (N × η) of the number N of light guides and the transmission rate η of the light guides, it is possible to configure a light energy time divisional distribution device that can be applied to various purposes and purposes. Then, this means that there is a certain degree of freedom in the range where the relationship between the original light receiving area S0 of the incident light 6 and the irradiation side total area ΣSm irradiated at the tip of the reflected light 8 in FIG. It is possible because it is.

  As described above, according to the equation (17), it is possible to irradiate light having the same peak photon quantum flux density (D0 = D) to the irradiation side total area ΣSm of the light receiving area S0 or more depending on the conditions. On the other hand, by irradiating the irradiation side total area ΣSm that is less than the light receiving area S0, it is possible to make the peak photon flux density higher than the original light, that is, (D> D0) depending on the conditions. effective.

  According to the present embodiment, it is possible to irradiate light having a photon flux density onto an area equal to or larger than the light receiving area. On the contrary, by irradiating an area smaller than the light receiving area, the photon flux density can be made higher than that of the original light.

  Further, the condenser 11 converts the condensed light 6 into linear light. Thereby, heat generation can be reduced. Further, by making the light 6 linear, it is possible to suppress unevenness of each time-divisional distributed light.

  Furthermore, the light energy can be distributed at high speed in a time division manner only by making the light incident on the rotated rotary cylinder 1. Therefore, it is possible to provide a simple method of time-divisionally distributing light energy. Other effects are similar to those of the first embodiment.

  Next, a light energy time division distribution method using the light energy time division distribution device 20 will be described.

  FIG. 7 is a flowchart diagram illustrating a light energy time division distribution method using the light energy time division distribution device according to the second embodiment. First, as shown in step S10 of FIG. 7, light is condensed. For example, the light collector 11 collects sunlight. The condenser 11 converts the condensed light 6 into a line shape.

  Next, as shown in step S20, the condensed light is made incident on the rotary cylinder 1. For example, the incident light guide path 12 causes the light 6 collected by the light collector 11 to enter the rotary cylinder 1.

  Next, as shown in step S30, the rotating cylinder 1 time-divisionally distributes the incident light. The rotary cylinder 1 has a first reflecting surface 4a and a second reflecting surface 4b. The first reflecting surface 4a reflects the incident light entering from one direction in the first direction 7a. The second reflecting surface 4b reflects the incident light in the second direction 7b different from the first direction 7a. In this way, the incident light 6 is time-divisionally distributed in the first direction 7a and the second direction 7b.

  Next, as shown in step S40, the light time-divided by the rotary cylinder 1 is guided to the irradiation range, for example, the irradiation ranges 15a and 15b. The light reflected in the first direction is guided to the irradiation range 15a, and the light reflected in the second direction is guided to the irradiation range 15b. Each of the guided light irradiates the irradiation areas 15a and 15b. In this way, the light energy can be time-divided by using the light energy time-division distribution device 20.

(Modification)
Next, a modified example of the second embodiment will be described.
FIG. 8 is a diagram illustrating a light energy time division distribution device according to a modification of the second embodiment. As shown in FIG. 8, in the light energy time divisional distribution device 20a of the present modification, the light time-divisionally distributed by the rotary cylinder 1 is guided to the irradiation range 15 via the reflected light guide path 13, and the artificial light source is used. The light from 30 is guided to the irradiation range 15 via the light guide path 31. The artificial light source 30 is, for example, an LED or a metal halide lamp.

  With such a configuration, it is possible to broaden the options of methods for irradiating the illumination range 15. That is, when strong light is required, the irradiation range 15 can be illuminated by time-divisionally distributing the sunlight by the rotary cylinder 1. When weak light is required, the irradiation range 15 can be irradiated with the light of the artificial light source 30.

(Embodiment 3)
Next, a third embodiment will be described. The present embodiment is an example of a plant factory using a light energy time division distribution device.

  FIG. 9 is a diagram exemplifying the light energy time division distribution device according to the third embodiment. As shown in FIG. 9, the light energy time divisional distribution device 30 arranges plants 40a and 40b in the irradiation ranges 15a and 15b. Then, the light 6 time-divided by the rotary cylinder 1 is applied to the plants 40a and 40b through the illuminators 14a and 14b. Other configurations and operations of the light energy time division distribution device 20 are similar to those of the second embodiment.

  Currently, LED light sources, fluorescent lamps, sodium lamps, metal halide lamps, and other artificial lights used in fully artificial light type plant factories cannot sufficiently raise the brightness and PPFD due to the problems of heat generation and power consumption.

  On the other hand, in the present embodiment, it is possible to cultivate the plant at a photon flux density (PPFD) equivalent to that near the equator, even though the plant is cultivated in Japan. Therefore, it is possible to cultivate a positive plant, which has been difficult with conventional artificial light.

  When the light-receiving surface is to obtain an irradiation-side photon flux density equal to or higher than the irradiation-side photon flux density D, the irradiation-side total area ΣSm is equal to the light-reception area S0, and the passage ratio η is 2 distributions. It is assumed that 60% time-divisional distributed lighting will be performed. In this case, the following expressions (23) to (25) are applied to the expression (17).

As a result, the following equation is obtained.

  Therefore, the photon flux density D on the irradiation side is 1.2 times the photon flux density D0 on the light receiving surface. The result will be described with a more realistic example. If the light receiving place is on the surface of the earth in the vicinity of 35 degrees north latitude, it means that the irradiation side can perform light irradiation with a photon flux density near the equator. That is, when the light energy time-sharing distribution device 30 is applied to a plant factory, it is possible to cultivate plants at a photon flux density (PPFD) having a peak illuminance equivalent to that near the equator even though the plants are cultivated in Japan. .

  However, to supplement, when applying to plant cultivation, it is necessary to assume that the photosynthetic rate of the plant in the blinking light of a specific cycle and a specific duty ratio by time division distribution is equal to or higher than the photosynthetic rate of the plant in continuous light. To do. In more specific cases, Non-Patent Document 1 discloses cultivation of salad vegetables. There, when intermittently irradiating light in a light-dark cycle with a short interval of about 200 microseconds, the rate of photosynthesis and the growth rate per unit amount of light can increase by 20 to 25% compared to continuous light. It is disclosed.

In this way, accelerating the photosynthesis of plants also fixes CO ₂ in the atmosphere to organic matter, which is effective in preventing global warming.

  As mentioned above, the LED light source cannot set the brightness and PPFD sufficiently, so the LED light source is set near the plant. However, in this case, the heat generated by the LED light source has an effect such as burning the plant. In the light energy time-division distribution device 30 in the present embodiment, the positions of the condenser 11 and the rotary cylinder 1 can be kept away from the plant. Therefore, it does not hinder the growth of plants.

  According to the light energy time-sharing distribution device 30 of the present embodiment, even in a plant factory using sunlight, cultivation can be performed in the same area as a plant factory using artificial light. Consider the case where this device is used in a plant factory. In order to realize a light-dark cycle of 200 microseconds, which is said to accelerate the growth of salad vegetables, the rotary cylinder 1 consisting of 60 pairs of two logarithmic spiral curves with different curvatures must be rotated about 83 times per second. I won't. Therefore, high speed rotation of the rotary cylinder 1 is required.

  In order to reduce the number of rotations of the rotary cylinder 1, it is necessary to increase the number of the reflection surfaces 4 per one rotation. If an attempt is made to increase the number of reflecting surfaces 4 without changing the size of the rotary cylinder 1, the area of each reflecting surface 4 becomes smaller. Therefore, the precision of the reflecting surface 4 at the time of manufacturing is required. However, a plant factory can secure a sufficient area. Therefore, it is possible to deal with the problem by increasing the size of the rotary cylinder 1 and increasing the area of the reflecting surface 4 per surface.

(Embodiment 4)
Next, a fourth embodiment will be described. The present embodiment is an example of a building using the light energy time division distribution device 40. That is, in a building such as a house or an office building, natural light 6 is taken in from a condenser 11 installed on a rooftop or the like and distributed to a plurality of rooms, thereby reducing the power consumption of electric lighting.

  FIG. 10 is a diagram illustrating a light energy time division distribution device 40 according to the fourth embodiment. As shown in FIG. 10, the light energy time division distribution device 40 is provided, for example, in a house. The light collector 11 is provided on the roof of the residential area. The light 6 collected by the light collector 11 is time-divisionally distributed by, for example, the rotary cylinder 1 provided on the back of the ceiling, and is guided to a plurality of rooms in the house. Rooms 18a and 18b are provided in the illumination ranges 15a and 15b. Then, the rooms 18a and 18b are illuminated by the illuminators 14a and 14b.

  In addition, a solar power generation panel 23 is provided on the roof. The electric power generated by the solar power generation panel 23 is transmitted to the storage battery 25 through the cable 24. Thereby, the electric power stored by the storage battery 25 can be used as needed.

  Here, how the people in the rooms 18a and 18b feel the brightness of the emitted light when the rotation speed of the rotary cylinder 1 is sufficiently high will be examined. The human eye is unaware that fluorescent or incandescent bulbs are blinking at a rate of about 100 hertz or faster. When the blinking speed of light and dark in FIG. 10 is fast enough, human eyes do not notice the blinking. Therefore, the human eye has the illusion that it is continuously illuminated.

  As described above, the characteristic that a person recognizes the brightness when the blinking speed is sufficiently fast follows "Talbot's law". That is, it is approximately proportional to the product of the luminance of the light source and the duty ratio. The brightness of the light source in this case is the photon flux density D on the irradiation side. The duty ratio is (TL / T) in FIG. The duty ratio is (1 / N) when the TLs of the respective light guide paths are all the same time.

  Therefore, the brightness perceived by a person is proportional to (D / N). That is, when the brightness of light that a person feels on the irradiation side of blinking light is defined as illuminance Dp (where the unit is the same as the photon flux density), the illuminance Dp is as follows.

Here, the equation (17) is solved for the photon flux density D 1 on the irradiation side.

This is applied to the equation (27).

  Thus, the illuminance Dp does not depend on the number N of light guide paths, but is proportional to the photon flux density D0 on the light receiving side. Here, the ratio of the photon flux density D0 on the light receiving side to the brightness illuminance Dp that a person feels on the irradiation side is defined as an illuminance ratio B. It is assumed that the light wavelength spectral distribution does not change between the light receiving side and the irradiation side. Then, since the ratio of illuminance and the ratio of photon flux density are the same, the following is obtained.

By applying this to the equation (29) and arranging it, the following relationship can be derived.

  Here, before the specific description of the industrial effect, the presupposed event will be further described. The illuminance of electrical lighting in offices etc. is generally set between 750 and 1500 lux. On the other hand, the illuminance of sunlight at around 10:00 am in latitudes near Japan exceeds 10,000 lux. It is said that the illuminance at the brightest time of summer and snowy mountains is over 100,000 lux.

  In other words, the illuminance of sunlight is about 10 to 100 times higher than that required for offices. Description will be given on the premise of this phenomenon. For example, the illuminance ratio B, which is the ratio of the brightness on the light-receiving surface to the brightness on the irradiation side, is set to 1/10 (= 0.1). Consider the relationship between the light-receiving surface area S0 and the irradiation-side total area ΣSm in a system that performs time-divisional distributed illumination with a transmittance η of 60%. The transmittance η is set to 0.6 and the illuminance ratio B is set to 0.1, which is applied to the equation (31). Then, ΣSm / S0 is obtained as 6.

  That is, it is possible to perform time-division distribution to the irradiation side total area ΣSm which is 6 times the area S0 of the light receiving surface. In other words, the area S0 of the light receiving surface is 1/6 of the total irradiation side area ΣSm.

  The result of this trial calculation will be described using a more specific example of a house. Using such a time-sharing distributed lighting system, when the time-sharing distributed lighting is applied to three rooms with 20 square meters (about 12 tatami mats) per room, the irradiation side total area ΣSm is 60 square meters (approximately It is 36 tatami mats). The area S0 of the light receiving surface of the concentrator installed on the rooftop or roof required for this is 10 square meters (about 6 tatami mats), which is 1/6 of the area.

  From the above specific example of the application to the lighting of the building, the industrial effect will be described again by further dividing it into two points.

  If the mechanism of time-divisional distributed illumination is applied to a plurality of rooms in a space where people are active as in the above example, the light collector 11 having a light-receiving area sufficiently smaller than the total area of each room can cover it. Therefore, it is possible to save space and reduce the size of the condenser 11. Therefore, it is possible to reduce the material cost and the construction cost related to the installation of the condenser 11 and the condenser 11.

  In addition, by enabling the space-saving and downsizing of the condenser 11 in this way, let's collect solar energy at a place where sunlight can be collected, such as a rooftop of a building, a roof, a balcony, a wall surface, or a garden. In that case, there is no need to reduce the space for installing other solar light-using equipment such as a solar panel or a solar heat collector.

  Furthermore, the time-divided light makes it possible to suppress the electric lighting in the living space. As a result, electricity used for electric lighting can be saved. This is effective in all rooms where the light at the tip of the light guide is irradiated. Therefore, depending on the number N of light guide paths, it is possible to realize a relatively large energy saving due to the power saving of the electric lighting as a whole.

  As a supplementary note, in the practical implementation of such a system that performs time-divisional distributed illumination, it is necessary to take measures against the change in the illuminance of sunlight depending on the time, season, and weather. For example, the illuminance around noon on a clear day in midsummer is about 1000 to 10,000 times the illuminance around 10 am on cloudy days. Therefore, if it is too bright, a mechanism for dimming is required. On the contrary, when it is dark, a mechanism to supplement the illuminance with electric lighting is necessary.

  It is desirable that these illuminance adjustments be automatically adjusted while sensing the illuminance on the light receiving side, the irradiating side, or both. In addition, in order to realize the dimming function for the purpose of suppressing the brightness, it is possible to regenerate even more if a mechanism for irradiating the light on the removed side to the panel for solar power generation and converting it into electric energy It has the effect of contributing to the promotion of energy use.

  In addition, the place where the dimming function is installed will be done somewhere between the light receiving surface and the passage route of the irradiator, and the installation, purpose, method of use, and operation of such a system that performs time-divisional distributed illumination. It is desirable to carry out at one or more places suitable for the maintenance method.

  Here, as a further supplement, when clouds or a flying object obstruct direct sunlight, the illuminance may change momentarily and greatly. Therefore, it is desirable that the mechanism of dimming and the mechanism of supplementary light be able to sufficiently follow the assumed change rate of the illuminance.

  The present invention is not limited to the above-mentioned embodiments, but can be modified as appropriate without departing from the spirit of the present invention. For example, the rotation speed of the rotary cylinder 1, the size of the rotary cylinder 1, the number of reflection surfaces, the shape, etc. can be adjusted to optimal conditions. Further, the rotary cylinder 1 is not limited to being used for a light energy time division distribution device. It may be used for a device that distributes light, such as a projection device and a video device. Furthermore, the light energy time divisional distribution device is not limited to application to plant factories and buildings. It can be applied wherever light needs to be distributed.

DESCRIPTION OF SYMBOLS 1 rotary cylinder 2 shaft 3 outer peripheral surface 4 reflective surface 4a first reflective surface 4b second reflective surface 4c third reflective surface 4d fourth reflective surface 4e fifth reflective surface 4f sixth reflective surface 5 spokes 6, 8, 8a, 8b Light 7a 1st direction 7b 2nd direction 9 Logarithmic spiral curve 9a, 9b Part 20, 20a, 30, 40 Light energy time division | segmentation apparatus 11 Condenser 12 Incident light light guide 13, 13a, 13b Reflected light light guide 14a, 14b Illuminator 15a, 15b Irradiation range 16a, 16b Light receiving part 17 Housing 18a 18b Room 21 Light 23 Solar power generation panel 24 Cable 25 Storage battery 30 Artificial light source 31 Light guide path 40a, 40b Plant I11, I21 Incident light I12, I22 Reflected light t1, t2 tangent lines r1, r2 distances S1, S2 perpendicular lines R11, R21 line O center

Claims (2)

A rotary cylinder having an outer peripheral surface and rotating about a central axis as a rotation axis, comprising: a first reflecting surface that reflects incident light incident in one direction in a first direction; A rotating cylinder having the outer peripheral surface including a second reflecting surface that reflects in two directions;
A first reflected light guide path for guiding the light reflected in the first direction to a first illumination range in a predetermined space;
A second reflected light guide path for guiding the light reflected in the second direction to a second illumination range in a predetermined space different from the first illumination range;
Equipped with
A light energy time division distribution device using sunlight as the incident light . The light energy time division distribution device according to claim 1, further comprising a light guide path that guides light of an artificial light source to the first illumination range or the second illumination range.