JP5158660B2 - Illumination device for plant cultivation with insect repellent effect and illumination cultivation method for plants - Google Patents

Description

  The present invention relates to a plant lighting cultivation method (method for producing a product) having an effect of avoiding pests and a plant cultivation lighting device.

  Nocturnal moths such as Tobacco moth and Spodoptera litura that have eaten flowers have acquired drug resistance and are therefore very difficult to control with insecticides. In carnations and roses, as an alternative control method, the use of night illumination with a yellow fluorescent lamp for antifungal activity is highly advanced against adult worms flying to the field for spawning.

  Further, there is a yellow LED insect-proof light system provided with a yellow light-emitting diode (hereinafter referred to as a yellow LED) instead of a yellow fluorescent lamp, which has a pest repellent effect enhanced by blinking the yellow LED (patent) Reference 1).

  In addition, a technique for delaying the flowering time by irradiating red LED light to short-day plants such as chrysanthemum, kalanchoe, cactus cactus, poinsettia, ligers begonia, red gypsophila, perilla and strawberry is known (patent document). 2).

JP 2003-284482 A JP-A-8-228599

  Such an anti-lighting illumination may cause unintended flowering suppression for short-day plants. A pest repellent effect is obtained by irradiating the emitted light of the yellow LED to the chrysanthemum, and the effect is higher as the irradiation time is longer. On the other hand, chrysanthemum, which is a short-day plant, has a problem that the flowering is suppressed by the illumination and the flowering time is delayed. The longer the irradiation time, the higher the degree of flowering suppression. As described above, the pest repellent effect and the flowering inhibitory effect are usually associated with each other.

  An object of the present invention is to provide a cultivation method having an insect repellent effect such as fungi control while controlling flowering suppression of short-day plants such as chrysanthemum, and to provide a lighting device suitable for such cultivation. It is.

  The lighting device for plant cultivation of the present invention includes a light emitting unit, a drive unit that is connected to the light emitting unit and supplies predetermined pulsed power, and a power supply unit that supplies power to the drive unit, The light emitting unit is a plant cultivation lighting device including a plurality of LED chips, and the light emitted from the light emitting unit has a light emission peak wavelength in a green to yellow region, and the driving unit sets the LED chip to a predetermined level. It blinks in a blinking pattern of light period width and dark period width, and the blinking is that duty = light period width / (light period width + dark period width) is 9% to 50%, and flowering of short-day plants A lighting device for plant cultivation characterized by having an insect repellent effect with almost no suppression.

In the plant cultivation lighting device of the present invention, the duty is preferably 30% or less.
In the plant cultivation lighting device of the present invention, the dark period width is preferably 200 ms or less.

  In the plant cultivation lighting device of the present invention, the LED chip is preferably an AlGaInP-based LED.

  In the lighting device for plant cultivation of the present invention, the light emitting unit includes an LED chip made of a nitride semiconductor, and a phosphor that absorbs part of the light emitted from the LED chip and emits yellow light. Is preferred.

  In the plant cultivation lighting device of the present invention, it is preferable that the waveform of the blinking pattern is further pulse-width modulated within the light period width.

  The lighting cultivation method for plants of the present invention is a cultivation method for illuminating plants at night or in an environment not exposed to light, using any one of the above plant cultivation lighting devices, and controls the flowering of short-day plants. This is a lighting cultivation method for a plant having an insect repellent effect that hardly occurs.

  According to the cultivation method of the present invention, it is possible to obtain an insect-repellent effect such as a fungicide effect while controlling the flowering suppression by illumination cultivation of short-day plants such as asteraceae plants.

  Moreover, by using the lighting device for plant cultivation of the present invention for cultivation of short-day plants such as asteraceae plants, it is possible to obtain an insecticidal effect such as a fungicide effect while controlling the flowering inhibition.

It is a block diagram which shows the method of evaluating the flowering response characteristic of a chrysanthemum with respect to the night illumination from which a wavelength differs. It is a spectrum distribution map of the emitted light of the illuminating device which tests the wavelength dependence with respect to the flowering of chrysanthemum. It is a figure which shows the influence which the illumination by LED from which spectral distribution differs has on the flower arrival day of an autumn witch. It is a spectrum distribution map of the illuminating device of the yellow LED and the yellow fluorescent lamp for comparison in the first embodiment. 6 is a diagram illustrating a pulse waveform of emitted light from the illumination device according to Embodiment 1. FIG. FIG. 3 is a circuit configuration diagram of the lighting device in the first embodiment. 3A is a top view and a cross-sectional view of a light emitting unit in Embodiment 1. FIG. It is a figure which shows the influence which the blinking pattern by the night illumination by yellow LED in Embodiment 1 and the difference in illumination intensity have on the arrival number of flowers of autumn cherries. 4 is a graph showing the relationship between duty in night illumination with yellow LEDs and the number of flower arrival days in the first embodiment. It is a figure which shows the cultivation method of chrysanthemum in Embodiment 2. FIG. It is a figure which shows the cultivation procedure of chrysanthemum in Embodiment 2. FIG. It is a figure which shows the cultivation procedure of the other chrysanthemum in Embodiment 2. FIG. FIG. 5 is a circuit configuration diagram of a lighting device in a second embodiment. FIG. 10 is a diagram illustrating a waveform of a light emission pulse of a lighting device according to Embodiment 3. FIG. 10 is a schematic diagram showing chrysanthemum growth in the fourth embodiment. FIG. 6 is a circuit configuration diagram of a lighting device according to a fourth embodiment. It is explanatory drawing of the conversion table in the illuminating device of Embodiment 4. FIG. It is the upper side figure and sectional drawing of yellow fluorescent LED in Embodiment 5. FIG. It is a spectrum distribution map of yellow fluorescent LED in Embodiment 5, and yellow LED for a comparison. It is a figure which shows the response characteristic of the emitted light of yellow fluorescent LED in Embodiment 5, and the AlGaInP type | system | group yellow LED for a comparison.

(Evaluation of visual characteristics of firewood for lighting)
The following reports have been made on the visual characteristics of acupuncture lighting. When light is applied to the compound eye of a night moth adult, a weak voltage is generated. With the retinal potential measurement system that amplifies and analyzes this voltage, it is possible to determine whether or not the night moth adults are strongly recognizing the light. This retinal potential measurement system analyzed the visible wavelength and the visible blinking frequency of adult moths, and it was shown that the wavelength was 450 to 600 nm and the frequency was 40 to 60 Hz (JSAM64 ( 5): 76-82, 2002, plant environmental engineering 19 (1), 2007).

  The activity of night moths is suppressed when the compound eye is brightly adapted by lighting, and conversely, the activity becomes active when darkly adapted in the dark. With the retinal potential measurement system, focusing on the magnitude of the retinal potential generated by illumination and its duration, an illumination method effective for maintaining the bright adaptation state for a long time was studied. As a result, it has been confirmed that the flashing pattern is effective under a lighting period of approximately 20 ms and the light intensity is illuminance of 1 lux or more.

  In addition, we investigated the antifungal effect of nighttime lighting using yellow LEDs in the cabbage field, and the number of parasite larvae of night moths such as Tobacco moth and Spodoptera spp. It has been shown to be suppressed from 1/7 to 1/8 (Plant Environmental Engineering 19 (1), 2007). This is the knowledge that is the basis for the action of night owls with flashing light as well as continuous light.

(Evaluation of wavelength dependence of chrysanthemum flowering response)
FIG. 1 shows a method for evaluating the flowering response characteristics of chrysanthemum to night illumination with different wavelengths. The lighting device 100 was installed at a position of 170 cm above the planter 50 where the autumn chrysanthemum “Shima” 60 was planted.

  The wavelength of the lighting device 100 was changed for the experiment. FIG. 2 is a spectrum distribution diagram of the emitted light of the illumination device for experimenting the wavelength dependency of chrysanthemums. Each illuminating device uses an LED as a light source, and each emission color and peak wavelength are blue (463 nm), green (519 nm), yellow-green (576 nm), yellow (597 nm), and red (646 nm).

  Illumination was performed at night from 22:00 to 2pm under different conditions for each treatment section shown in Table 1, and the effects of irradiance and wavelength on flowering were investigated.

  Table 1 shows the configuration of the treatment area.

  The treated area was 3 repeats per 3 wards, that is, 3 sets of 3 plants per planter were planted as 1 ward, and the non-pinching cultivation was performed. Each planter 50 has a volume of 6 liters (width 15 cm × length 32 cm × depth 13 cm).

  The lighting period was adjusted from November 20, 2007 to January 7, 2008, from 8 days after planting until the end of night lighting, once a week so as to adjust the growth point to the predetermined irradiance according to the growth. In addition, for comparative evaluation, a planter equivalent to the above was prepared (no treatment) placed under natural daylight without performing night illumination.

  FIG. 3 is a diagram showing the effect of illumination by LEDs having different spectral distributions on the number of days when flowers arrive in autumn. According to this, the number of flower arrival days (the number of days from the night illumination end date to the flowering date) is larger in all treatment areas except blue-100 and green-10, and the set value of irradiance is higher than that of no treatment. There were so many. For LEDs except blue, if the irradiance is the same, the number of days to reach red is generally the largest, and then decreases in the order of yellow, yellowish green, and green.

  That is, the flowering suppression effect of chrysanthemum is that red is the strongest, followed by weakness in the order of yellow, yellow-green, green, and blue. In addition to blue (green to red), the larger the irradiance setting value, the same effect Has been verified to be strong.

<Embodiment 1>
The present embodiment relates to a lighting cultivation method in which flowering of chrysanthemum is controlled and a lighting device using a yellow LED therefor.

(Chrysanthemum lighting device)
FIG. 1 shows a method for evaluating the flowering response characteristics of chrysanthemum to night illumination with different wavelengths. The lighting device 100 equipped with a yellow LED as a semiconductor light emitting device is installed at a position 170 cm above the planter 50 where the autumn giku “Shinma” 60 is planted, and the influence of the irradiance and pulse lighting conditions of the lighting device 100 on the chrysanthemum investigated.

  FIG. 4 is a spectrum distribution diagram of the illumination device of the AlGaInP yellow LED and the comparative yellow fluorescent lamp used in this illumination device. Hereinafter, in the present embodiment, the AlGaInP yellow LED is simply referred to as a yellow LED. According to this, the emitted light of the yellow LED is a narrow band having a peak wavelength of 597 nm and a half-value width of 20 nm or less, and the red light component having a wavelength of 600 to 700 nm is considered to have the strongest flowering suppression effect. Since there are few fluorescent lamps, there is little suppression of flowering.

  FIG. 5 is a diagram illustrating a pulse waveform of the emitted light of the present illumination device. This illumination device drives a yellow LED with a rectangular pulse current, but the emitted light follows the drive current, blinks with a rectangular wave consisting of a light period width and a dark period width, and the duty is light period width / ( Light period width + dark period width).

  FIG. 6 is a circuit configuration diagram of the lighting device. The illuminating device 100 includes a light emitting unit 110, a driving unit 120 that is connected to the light emitting unit, supplies a predetermined pulsed power, and a power supply unit 140 that supplies power to the driving unit. It is configured to obtain pulsed emitted light. The drive unit 120 includes a pulse generation circuit 121 that converts power supplied from the power supply unit 140 into predetermined pulse-shaped power, a relay 122, and a timer 123, and contacts the relay 122 at a time set in advance in the timer 123. Are opened and closed, and the driving power generated by the pulse generation circuit 121 is supplied to the light emitting unit 110 for a predetermined period.

  FIG. 7 is a top view and a cross-sectional view of the light emitting unit 110. The light emitting unit 110 includes a substrate 111 and a yellow LED 112 in which a total of 32 pieces, 8 in length and 4 in width, are mounted on the substrate in a grid pattern. An electrode and a wiring pattern (not shown) are formed in advance on the substrate, and each yellow LED 112 is configured to be connected in series.

  According to the present lighting device, the yellow LED 112 mainly emits a spectrum necessary for prevention, and emits less unnecessary spectrum.

  Note that the configuration of the illumination device shown in the present embodiment is an example, and any configuration may be used as long as the emission wavelength and the pulsed emission light can be obtained, and the configuration is not necessarily limited to the above configuration. For example, a configuration in which the setting conditions of the pulse and timer are controlled by a microcomputer, and a configuration in which the relay 122 and the timer 123 include a solid state relay that is a non-contact point may be used. The number, arrangement method, or wiring of the yellow LEDs 112 can be appropriately selected. Further, the light emission pulse may be changed without making the amplitude and the pulse width constant. The waveform of the power supplied to the light emitting unit is not limited to a rectangular wave, and a triangular wave, a sine wave, or the like can be selected.

(Evaluation of chrysanthemum flowering response to flashing lighting at night)
Next, night illumination was performed between 16:30 and 7:30 under different conditions for each treatment section shown in Table 1, and the effects of illuminance and dark period width on flowering were investigated.

  Table 2 shows the configuration of the treatment area.

  The treated area was 3 repeats per 3 wards, that is, 3 sets of 3 plants per planter were planted as 1 ward, and the non-pinching cultivation was performed. Each planter 50 has a volume of 6 liters (width 15 cm × length 32 cm × depth 13 cm).

  The illumination period was adjusted from November 20, 2007 to March 4, 2008, from 8 days after planting until the end of the experiment, once a week so as to adjust the growth point to the predetermined illuminance according to the growth. The illuminance is a value measured with an illuminometer after the yellow LED is continuously turned on temporarily. In addition, for comparative evaluation, a planter equivalent to the above was prepared (no treatment) placed under natural daylight without performing night illumination.

  FIG. 8 is a diagram showing the influence of the difference between the blinking pattern and the illuminance in the night illumination by the yellow LED on the number of flower arrival days of autumn cherries. According to this, the number of flower arrival days (the number of days from the planting date to the flowering date) is larger in all the continuous lighting sections (3-0, 5-0, 10-0) and the set illuminance is higher than in the case of no treatment. There were so many. In addition, the number of flower arrival days from the planting date decreased in the blinking section as compared to the continuously illuminated section within the same set illuminance. The degree of decrease in the number of flower arrivals due to blinking was the largest at 10 lux with the highest set illuminance, then 5 lux, and a slight decreasing trend at 3 lux.

  FIG. 9 is a graph summarizing the case of 10 lux in the result of FIG. 8 with the horizontal axis as the duty. The dotted line is the number of days without flowering (no lighting). From this figure, it can be seen that the suppression of flowering is less at 50% or less than that when the duty is 100%, and that the suppression of flowering hardly occurs when the duty is 30% or less.

  In this way, in the night illumination with yellow LED, when the illuminance near the chrysanthemum growth point is 3, 5, 10 lux, by using any flashing illumination, the effect on the number of flower arrivals compared to continuous illumination It became clear that it could be reduced.

  Based on the knowledge as described above, the inventors have focused on the fact that one of the advantageous characteristics of an LED, which is easy to drive at high speed, and led to the invention of the present lighting cultivation method and lighting device. It was.

  In addition, this lighting cultivation method is applicable also to plants, such as a carnation, a rose, an eustoma and a tomato which were not badly recognized for growth by the illumination by the conventional yellow fluorescent lamp.

<Embodiment 2>
The present embodiment relates to a cultivation method for dividing a farm field into several areas and performing night illumination under different irradiation conditions for each area, and an illumination device therefor. Chrysanthemum is a short-day plant that does not bloom unless the length of the day is reduced. Utilizing this property, electric cultivation is carried out to control the flowering date according to the chrysanthemum shipping date. In the present embodiment, the night illumination of the electric cultivation is performed with a yellow LED, and the illumination having both effects of flowering control and insect repellent effect on the cocoon is provided, and the LED is easy to control blinking. It was made paying attention to the point.

  Hereinafter, an example of electric lighting cultivation will be described. The chrysanthemum is illuminated at night for a predetermined period after planting, and when the height is grown from 50 to 60 cm in the ring giku, the lighting is stopped when the height is grown from 20 to 25 cm in the spray giku. Furthermore, cultivation is continued for about 50 days under untreated conditions (short day conditions), and when the height grows to about 90 cm, it is flowered and harvested. Therefore, in actual cultivation, a flowering date is first determined, and a fixed planting date is determined by calculating backward from here.

  FIG. 10 is a diagram showing a chrysanthemum cultivation method according to the present embodiment. Chrysanthemum is planted in three rows of ridges in the field 70, and the ridges are named areas A, B, and C, respectively. Corresponding to each area, the light emitting units 210A, 210B, and 210C of the illumination devices 200A, 200B, and 200C are installed so as to irradiate chrysanthemum from above. Since the directivity of the emitted light from the LED is stronger than that of the fluorescent lamp, each of the lighting devices 200A, 200B, and 200C can irradiate each of the areas A, B, and C independently.

  FIG. 11 is a diagram showing a chrysanthemum cultivation procedure. Usually, after planting, night illumination is performed and no treatment is made about 50 days before the scheduled flowering date. In the case of no treatment, flowering is not suppressed, and the flowering occurs about 50 days later.

  In the present embodiment, after planting, after performing illumination cultivation in the flowering control mode described later in the first lighting cultivation period, the flowering / switching mode (described later) is switched to the flowering non-suppression mode (described later) in the second lighting cultivation period. Harvest. At that time, for each of the areas A, B, and C, the degree of flowering suppression during the first lighting cultivation period can be changed by changing the duty, thereby shifting the flowering / harvest time.

  Here, the flowering control mode and the flowering non-suppression mode will be described (the flowering control mode in a broad sense includes the flowering non-suppression mode). As shown in FIG. 9, the number of chrysanthemum flower arrival days varies depending on the duty, and the greater the duty, the higher the flowering suppression effect. By paying attention to this characteristic and setting different duty for each area, flowering dates can be dispersed.

  The lighting device 200 in FIG. 10 is configured to be able to switch the duty of night lighting. For example, each lighting device 200 has an illuminance of 10 lux, and the dark period width of the flowering control mode in the first lighting cultivation period is 0 for the lighting device 200A (continuous lighting), 20 ms for the lighting device 200B (duty 50%), and lighting. The device 200C sets 100 ms (duty 17%). In any lighting device, the light period width is 20 ms. In this way, as shown in FIG. 9, the shorter the dark period width, that is, the larger the duty, the longer the number of flower arrival days, so the flowering date can be changed for each area.

  Alternatively, the flowering date can be postponed by sequentially postponing the timing for switching the night illumination mode for each area. As shown to Fig.12 (a), night illumination is implemented with the illuminating device 400 mentioned later, and the flowering non-suppression mode (dark period width 200ms (duty 9) is carried out from the flowering control mode (continuous lighting) about 50 days before the scheduled flowering date. %)). At this time, when the mode switching time is shifted in the order of areas A, B, and C, the flowering date can be postponed for each area.

  Moreover, a flowering day can be disperse | distributed only by postponing a fixed planting date for every area. As shown in FIG. 12 (b), the conditions (light period width, dark period width, illumination period) of the flowering control mode and the non-flowering suppression mode for each area are made the same, and the fixed planting date is postponed by several days. Thus, the flowering date can be postponed by several days.

  When the flowering date can be controlled for each area, the flowering date is dispersed, which is convenient for harvesting. The problem of concentrating flowering days and being extremely busy with harvesting as before is solved.

  Also, conventionally, since the period from the end of the night illumination period to flowering was untreated, it was unavoidable that the night moth adult flies, but according to the present embodiment, even in this period, the flowering non-suppression mode The anti-glare effect can be obtained by the illumination. In addition, conventionally, in order to perform flowering control, complicated operations such as partitioning between areas with a light-shielding curtain were involved. However, according to the present embodiment, since the setting of the lighting device can be changed, the convenience is high. .

  FIG. 13 is a circuit configuration diagram of the illumination device 400. The lighting device 400 includes light emitting units 410A, 410B, and 410C, and is connected to the driving unit 120 via switches 401A, 401B, and 401C, respectively. The drive unit 120 includes a drive unit 120A for a flowering control mode and a drive unit 120B for a flowering non-suppression mode. The drive unit 120A is a continuous lighting drive, the light period width of the drive unit 120B is 20 ms, and the dark period width is 200 ms. (Duty 9%). According to this configuration, the mode can be switched by switching the switch. Further, even if the number of light emitting units is increased, only two driving units are required, which is advantageous in reducing the manufacturing cost of the lighting device.

  In addition, although the flowering control mode was set to continuous lighting, in order to adjust the illuminance, as described in Embodiment 3, it is felt that continuous lighting is performed for insects and plants to be cultivated even during the continuous lighting period. Such pulse width modulation may be performed.

<Embodiment 3>
In the present embodiment, the waveform of the light emission pulse is further subjected to pulse width modulation within the light period width.

  As shown in FIG. 14, the waveform of the light emission pulse in this embodiment has a light period width of 20 ms. During this period, for example, a light-in period light-on period of 1 ms and a light-in period light-out period of 1 ms are alternately 10 In other words, the light duty is set to 50%. The light period width duty means the light period width lighting period / (light period width lighting period + light period width lighting period).

  According to this, it is estimated that the night moth adults are difficult to recognize the light-in period light-on period and the light-in period light-out period as blinking in the light period width, as if they were continuous light.

  According to this embodiment, it is possible to reduce the total lighting time while maintaining the light period width effective for maintaining the light adaptation state of the night moth adult for a long time, the lower limit value of 20 ms. Therefore, it is possible to reduce power consumption and reduce the effect of suppressing chrysanthemum flowering without significantly impairing the antifungal effect.

<Embodiment 4>
This embodiment has a configuration in which the intensity of illumination is changed depending on the height of chrysanthemum.

  FIG. 15 is a schematic diagram showing chrysanthemum growth. If the height from the floor surface to the light emitting unit 110 is constant, the distance h from the chrysanthemum growth point to the light emitting unit 110 gradually approaches as chrysanthemum grows. At this time, if the intensity of the emitted light from the illumination device 100 is constant, the amount of light may be unnecessarily increased for the reasons described above. In view of this problem, as chrysanthemum grows, when the distance h from the chrysanthemum growth point to the light emitting unit 110 approaches, there is provided a means for reducing the light duty width duty of the lighting device 100 so that the light quantity is within a certain range. It is configured to be maintained.

  FIG. 16 is a circuit configuration diagram of the illumination device 300. The lighting device 300 includes a pulse generation circuit 121 having a variable duty within the light period width, a distance sensor 310 that measures the distance h from the emission surface of the light emitting unit 110 to the chrysanthemum growth point, and an appropriate brightness according to the distance h. A distance-light period width duty conversion table 311 (hereinafter referred to as a conversion table) for calculating the period width duty is provided, and a pulse of the light period width duty corresponding to the distance h is output. .

  As the distance sensor 310, for example, a known sensor such as one that includes a light emitting element and a PSD (position detecting light receiving element) and measures the distance by triangulation can be used. In addition, a sensor including a light receiving element that measures the intensity of light that is reflected from the light emitted from the light emitting unit 110 and is reflected back can be used.

  FIG. 17 is an explanatory diagram of a conversion table. The distance h from the light emitting unit 110 to the measurement position and the amount of light at the measurement position are plotted in advance in a scatter diagram, and the correlation is obtained. For example, as shown in FIG. 17A, it is assumed that the light quantity gradually increases in the order of A, B, and C in correspondence with the case where the distance h is gradually decreased in the order of a, b, and c. On the basis of this correlation, as shown in FIG. 17B, the light period width duty is set to A, A / B, and A / C corresponding to the case where the distance h is a, b, and c.

  According to this, the distance h from the growth point of chrysanthemum to the light emitting part 110 is a at the time of chrysanthemum planting, but the light amount is within a certain range even if b, c, etc. gradually become smaller as it grows. Can be maintained.

  When adjusting the amount of light according to the growth of chrysanthemum, it is necessary for humans to make adjustments using a luminometer, and it is generally considered to be adjusted uniformly within the field, but according to this embodiment, Since it is easy to automatically adjust the light quantity of the lighting device according to the growth of each chrysanthemum, the energy saving effect and convenience are high.

<Embodiment 5>
The present embodiment relates to a plant cultivation lighting device in which the AlGaInP-based yellow LED 112 in the lighting device 100 according to the first embodiment is replaced with a yellow fluorescent LED 115.

FIG. 18 is a top view and a cross-sectional view of the yellow fluorescent LED 115 in the fifth embodiment. In the yellow fluorescent LED 115, an LED chip 116 made of a nitride semiconductor that emits blue light and a phosphor 118 made of BOSE (Ba, O, Sr, Si, Eu) are dispersed, and the LED chip 116 is sealed. A stop resin 117 is provided. The phosphor 118 absorbs part of the blue light and emits a large amount of yellow light. Therefore, according to the yellow fluorescent LED 115, the blue light emitted from the LED chip 116 and the large amount of yellow light emitted from the phosphor 118 are mixed to emit yellow light.

  Table 3 compares the characteristics of the yellow fluorescent LED and the AlGaInP-based yellow LED used in the first embodiment.

  The comparative AlGaInP yellow LED does not contain a phosphor, and the chip itself emits yellow light. Comparing the luminous efficiencies in Table 3, it can be seen that the luminous efficiency of the yellow fluorescent LED is superior to that of the AlGaInP yellow LED.

  FIG. 19 is a spectrum distribution diagram of the yellow fluorescent LED and the comparative AlGaInP yellow LED in the present embodiment. Both the yellow fluorescent LED and the comparative yellow LED are driven with the same current value.

  In FIG. 19, when the luminous efficiency of the yellow fluorescent LED 115 and the comparative AlGaInP-based yellow LED are compared in a wavelength where night moths are visible, that is, in the region of 450 to 600 nm, the luminous efficiency of the yellow fluorescent LED 115 is high. Therefore, when the lighting device 100 includes the yellow fluorescent LED 115, the effect of energy saving can be further enhanced.

  Note that a blue light component of about 500 nm or less in the spectrum distribution of FIG. 19 may cause an attracting effect depending on the type of night owl. In order to eliminate this influence, it is preferable to provide a filter that suppresses transmission of the blue light component, for example, a filter that cuts 500 nm or less, between the lighting device 100 and the autumn chrysanthemum 60.

  Further, as the phosphor 118, in addition to BOSE, SOSE (Sr, Ba, Si, O, Eu), YAG (Ce activated yttrium, aluminum, garnet), α sialon ((Ca), Si, Al, O, N, Eu) and the like can be preferably used. Further, the emission efficiency can be further improved by changing the LED chip 116 from one emitting blue light to, for example, an ultraviolet (near ultraviolet) LED having an emission peak wavelength of 390 nm to 420 nm.

  FIG. 20A is a diagram showing response characteristics of the emitted light of the yellow fluorescent LED, where the horizontal axis represents time (1 ms / div), and the vertical axis represents emission intensity. As shown in FIG. 20A, the emitted light is pulse-driven not only in the case of the light period width 20 ms and the dark period width 20 ms (duty 50%) but also in the case of the light period width 1 ms and the dark period width 1 ms. Follow the current. The phosphor has the property that it emits afterglow for a while after the excitation light is extinguished and gradually attenuates with the lapse of time. However, if the dark period width is longer than 1 ms, the phosphor has a characteristic of the driving pulse current waveform. Since the afterglow time is extremely short, it is considered that the emitted light can follow the drive pulse current.

  Thus, using the yellow fluorescent LED, predetermined blinking can be obtained accurately in the blinking cycle (light period width 20 ms, dark period width 20 ms (duty 50%) or more) as shown in the first embodiment.

  FIG. 20B is a diagram showing response characteristics of emitted light of a comparative AlGaInP-based yellow LED. Needless to say, the AlGaInP yellow LED has a response waveform equivalent to that of the yellow fluorescent LED (theoretically, a faster response than that), and the predetermined blinking can be obtained accurately.

  In each embodiment described in the present application, an LED is mounted as the light source of the illumination device. However, if the light source has at least the emission spectrum of the emitted light and the high-speed response characteristics equivalent to those of the LED, Similarly, the effect of insect control and flowering control can be obtained. As such a light source, for example, a light source such as a discharge lamp or EL (electroluminescence) can be used.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

100, 300, 400 Illumination device, 401A, 401B, 401C switch, 110, 410A, 410B, 410C Light emitting unit, 310 Distance sensor, 311 conversion table, 112 Yellow LED, 115 Yellow fluorescent LED, 116 LED chip, 117 Sealing resin , 118 phosphor, 120, 120A, 120B drive unit, 121 pulse generation circuit, 122 relay, 123 timer, 140 power supply unit.

Claims (7)

A light emitting unit, a drive unit connected to the light emitting unit and supplying predetermined pulsed power, and a power supply unit supplying power to the drive unit, the light emitting unit including a plurality of LED chips A lighting device for plant cultivation,
The light emitted from the light emitting part has an emission peak wavelength in a green to yellow region,
The drive unit blinks the LED chip in a blink pattern of a predetermined light period width and dark period width,
The blinking is characterized in that duty = light period width / (light period width + dark period width) is 9% or more and 50% or less, and has an insect repellent effect without substantially suppressing the flowering of short-day plants. Lighting equipment for plant cultivation.   The plant cultivation lighting device according to claim 1, wherein the duty is 30% or less.   The lighting device for plant cultivation according to claim 1 or 2, wherein the dark period width is 200 ms or less.   The plant LED lighting device according to any one of claims 1 to 3, wherein the LED chip is an AlGaInP-based LED.   The light emitting unit includes an LED chip made of a nitride semiconductor, and a phosphor that absorbs a part of light emitted from the LED chip and emits yellow light. The lighting apparatus for plant cultivation of any one of these.   The lighting device for plant cultivation according to any one of claims 1 to 5, wherein a waveform of the blinking pattern is further pulse-width modulated within the light period width. A lighting method for plant cultivation according to any one of claims 1 to 6, wherein the plant is illuminated at night or in an environment not exposed to light,
A lighting cultivation method for a plant having an insect-repellent effect with almost no flowering suppression of short-day plants.

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