JP7617545B2 - Light irradiation method, lighting device, and lighting system for plant growth - Google Patents

Description

This disclosure relates to a light irradiation method for plant growth, a lighting device, and a lighting system.

Patent document 1 discloses a lighting device for growing plants that includes an illumination means for irradiating light onto plants and a control means for controlling the irradiation energy of the light emitted by the illumination means.

Patent No. 5335721

However, with conventional light irradiation methods for plant growth using lighting devices for plant growth, it is not possible to adjust the optimal light irradiation range and irradiation time according to the size and shape of the plant, making it difficult to adjust the growth of the plant by light irradiation. This makes it difficult to grow the plant into a desired shape. In addition, because the appearance of a plant irradiated with light does not change, people may become bored of looking at the plant.

The present disclosure therefore aims to provide a light irradiation method, lighting device, and lighting system for plant growth that can grow plants, maintain their vigor, and improve the appearance of the plants.

A light irradiation method for plant growth according to one aspect of the present disclosure includes using a white light-emitting diode that emits white light and a red light-emitting diode or a red phosphor that emits red light to irradiate the white light and the red light to a plant, controlling a radiant energy of the red light emitted from the red light-emitting diode or the red phosphor to be half or less of the radiant energy of the white light emitted from the white light-emitting diode, controlling at least one of an irradiation range, an irradiation direction, and an illuminance of the white light and the red light in accordance with at least one of a size, a shape, and a growth stage of the plant, and controlling at least one of an irradiation range, an irradiation direction, and an illuminance of the white light and the red light to execute a mode for promoting growth of the plant and a mode for suppressing leaf drop in the plant, The method includes controlling at least one of an irradiation range, an irradiation direction, and an illuminance to execute at least one of a mode for maintaining the vigor of the plant and a mode for maintaining the vigor of the plant and suppressing the occurrence of defoliation in the plant ; when executing the mode for promoting plant growth, irradiating the white light and the red light at 1200 lx or more and less than 3000 lx to a growth point of the plant including a top portion of the plant; when executing the mode for maintaining the vigor of the plant, irradiating the white light and the red light at 600 lx or more and 1000 lx or less to the growth point of the plant; and when executing the mode for maintaining the vigor of the plant and suppressing the occurrence of defoliation in the plant, irradiating the white light and the red light to a portion of 1/2 or less of the height H of the plant .

Moreover, an illumination device according to an aspect of the present disclosure includes a light source having a white light-emitting diode that emits white light and a red light-emitting diode or a red phosphor that emits red light, and irradiating a plant with the white light and the red light; and a control unit that controls a radiant energy of the red light emitted from the red light-emitting diode or the red phosphor to be half or less of a radiant energy of the white light emitted from the white light-emitting diode, and controls at least one of an irradiation range, an irradiation direction, and an illuminance of the white light and the red light in accordance with at least one of a size, a shape, and a growth stage of the plant, and the control unit executes a mode for promoting growth of the plant and a mode for suppressing leaf drop of the plant by controlling at least one of the irradiation range, an irradiation direction, and an illuminance of the white light and the red light. At least one of a mode for maintaining the vigor of the plant and a mode for maintaining the vigor of the plant and suppressing the occurrence of defoliation of the plant is executed by controlling at least one of the irradiation range, irradiation direction, and illuminance of the white light and the red light, and when executing the mode for promoting growth of the plant, the light source irradiates the white light and the red light at a growth point of the plant including the top of the plant with 1200 lx or more and less than 3000 lx, when executing the mode for maintaining the vigor of the plant, irradiates the white light and the red light at a growth point of the plant including the top of the plant with 600 lx or more and 1000 lx or less, and when executing the mode for maintaining the vigor of the plant and suppressing the occurrence of defoliation of the plant, irradiates the white light and the red light to a portion of the plant that is 1/2 or less of the height H of the plant .

Moreover, an illumination system according to an aspect of the present disclosure includes an illumination device having a white light-emitting diode that emits white light and a red light-emitting diode or a red phosphor that emits red light, and irradiating the white light and the red light to a plant; and a control unit that controls a radiant energy of the red light emitted from the red light-emitting diode or the red phosphor to be half or less of a radiant energy of the white light emitted from the white light-emitting diode, and controls at least one of an irradiation range, an irradiation direction, and an illuminance of the white light and the red light in accordance with at least one of a size, a shape, and a growth stage of the plant, and the control unit executes a mode for promoting growth of the plant and a mode for suppressing leaf drop of the plant by controlling at least one of an irradiation range, an irradiation direction, and an illuminance of the white light and the red light. and by controlling at least one of an irradiation range, an irradiation direction, and an illuminance of the white light and the red light, at least one of a mode for maintaining the vigor of the plant and a mode for maintaining the vigor of the plant and suppressing the occurrence of defoliation of the plant is executed , and when executing the mode for promoting growth of the plant, the lighting device irradiates a growth point of the plant including a top portion of the plant with the white light and the red light of 1200 lx or more and less than 3000 lx, when executing the mode for maintaining the vigor of the plant, the lighting device irradiates the growth point of the plant with the white light and the red light of 600 lx or more and 1000 lx or less, and when executing the mode for maintaining the vigor of the plant and suppressing the occurrence of defoliation of the plant, the lighting device irradiates a portion of the plant that is equal to or less than ½ of the height H of the plant with the white light and the red light .

The light irradiation method for plant growth disclosed herein can help plants grow, maintain their vigor, and improve their appearance.

FIG. 1 is a schematic diagram showing how a lighting device of a lighting system according to a first embodiment irradiates light onto a plant. FIG. 2 is a block diagram of the lighting system according to the first embodiment. FIG. 3 is a diagram showing the spectrum of white light emitted by a white light emitting diode, red light emitted by a red light emitting diode, or red light emitted by a red phosphor in the lighting system according to the first embodiment. FIG. 4A is a schematic diagram showing how the lighting device controls light distribution to change the irradiation range and illuminance, and FIG. 4B is a schematic diagram showing how the lighting device controls light distribution to change the irradiation direction. FIG. 5A is a schematic diagram showing how the lighting device controls light distribution to irradiate 1200 lx of light onto the growth point and 600 lx of light onto the lower leaves of the plant, and FIG. 5B is a schematic diagram showing how the lighting device controls light distribution to irradiate 600 lx to 1000 lx of light onto the growth point and 600 lx of light onto the lower leaves of the plant. FIG. 6 is a diagram showing the relationship between the elongation of a plant and the number of days when the lighting device of the lighting system according to the first embodiment irradiates the plant with light. FIG. 7 is a diagram showing the relationship between the number of fallen leaves of a plant and the number of days when the lighting device of the lighting system according to the first embodiment irradiates the plant with light. FIG. 8 is a flowchart showing the processing of the lighting system according to the first embodiment. FIG. 9A is a schematic diagram showing how light is emitted when the lighting devices of the lighting system according to the second embodiment are disposed above and below a plant. FIG. 9B is a schematic diagram showing the appearance when the upper lighting device irradiates light onto a plant and the appearance when the lower lighting device irradiates light onto a plant. FIG. 10 is a diagram showing the relationship between plant elongation and illuminance, the relationship between the number of fallen leaves and illuminance, and the relationship between photosynthetic sensitivity and illuminance when a lighting device of a lighting system according to embodiment 2 irradiates light onto the growth point of the plant. FIG. 11 is a diagram showing the relationship between plant elongation and illuminance, the relationship between the number of fallen leaves and illuminance, and the relationship between photosynthetic sensitivity and illuminance when a lighting device of a lighting system according to embodiment 2 irradiates light onto the lower leaves of a plant. FIG. 12 is a block diagram of a lighting system according to the third embodiment. FIG. 13 is a flowchart showing the processing of the lighting system according to the third embodiment. FIG. 14 is a diagram showing the relationship between the photosynthetic sensitivity and the irradiation angle, and the relationship between the luminance and the irradiation angle when the first lighting device on the upper side irradiates light onto a plant. FIG. 15 is a diagram showing the relationship between the photosynthetic sensitivity and the irradiation angle, and the relationship between the luminance and the irradiation angle when the second lighting device on the lower side irradiates light onto a plant.

The embodiments described below are all comprehensive or specific examples. The numerical values, shapes, materials, components, component placement and connection forms, steps, and order of steps shown in the following embodiments are merely examples and are not intended to limit the present disclosure. Furthermore, among the components in the following embodiments, components that are not described in an independent claim are described as optional components.

The following describes the embodiment in detail with reference to the drawings.

(Embodiment 1)
<Configuration: Lighting system 1>
FIG. 1 is a schematic diagram showing how a lighting device 10 of a lighting system 1 according to a first embodiment irradiates light onto a plant.

As shown in FIG. 1, lighting system 1 irradiates light to a target plant for growth and appreciation, thereby improving the growth and appearance of the plant. For example, in this lighting system 1, lighting device 10 irradiates light to a plant placed in a poorly lit location, such as indoors. The light irradiated to the plant is white light and red light. In this embodiment, white light and red light are sometimes collectively referred to as light. Furthermore, white light is a color of light that humans can recognize as white. Furthermore, red light is a color of light that humans can recognize as red, for example, light with a wavelength of 610 nm to 750 nm.

The plant is, for example, an ornamental plant. Ornamental plants are, for example, potted plants that mainly bear flowers, non-flowering herbs or foliage plants, vegetables such as tomatoes and eggplants, and fruit-bearing plants such as mandarin oranges and grapes. Furthermore, the plant is not limited to these examples and may be other plants.

Figure 2 is a block diagram of the lighting system 1 according to the first embodiment.

As shown in FIG. 2, the lighting system 1 includes one or more lighting devices 10, a control unit 20, a memory unit 30, an operation unit 40, and a power supply unit 50.

[Lighting device 10]
Each of the one or more lighting devices 10 irradiates a plant with white light and red light. In the present embodiment, unless otherwise specified, one lighting device 10 is used to irradiate a plant with light, and therefore, one lighting device 10 will be mainly described.

The lighting device 10 is capable of changing the light distribution and brightness of the emitted light. The light distribution is the direction and range of light emitted by the lighting device 10. For example, when changing the direction of light emission, the lighting device 10 rotates or the light source 10a of the lighting device 10 rotates, and the lighting device 10 changes the direction of light emission and changes the location of the plant that is irradiated. When changing the range of light emission, for example, the lighting device 10 can vary the light distribution from a narrow angle to a wide angle by changing the position of the light distribution control lens relative to the light source 10a.

The lighting device 10 includes a light source 10a having a white light-emitting diode 11 that emits white light and a red light-emitting diode 12 or a red phosphor that emits red light.

The light source 10a irradiates the plants with white light and red light. The lighting device 10 is placed on the ceiling, wall, etc. in a position that irradiates the plants with light. The lighting device 10 is mainly placed at a position higher than the plants.

Light source 10a emits light with a Feeling of Contrast Index (FCI), an index indicating the vividness of color, of, for example, about 120. FCI is based on 100. Light source 10a also emits at least white light and red light as light of two or more colors.

Figure 3 shows the spectrum of the white light emitted by the white light-emitting diode 11, the red light emitted by the red light-emitting diode 12, or the red light emitted by the red phosphor in the lighting system 1 according to embodiment 1.

As shown in Figures 2 and 3, the white light emitted by the white light emitting diode 11 has a maximum peak wavelength in the blue region (blue light). The blue region is, for example, a wavelength region of light that humans can recognize as blue, for example, light with a wavelength of 430 nm to 490 nm. In addition, in this embodiment, the color temperature of the white light is approximately 5000 K.

The red light emitting diode 12 or red phosphor of the light source 10a emits monochromatic red light (red light). The red light emitting diode 12 of the light source 10a may emit red light by wavelength conversion of laser light to the red phosphor. The red light emitted by the red light emitting diode 12 or red phosphor has peak wavelengths in the blue and red regions (red light), and has a maximum peak wavelength in the red region in particular. A narrow-band phosphor with a half-width of 50 nm or less is used as the red phosphor. Note that, although FIG. 2 shows an example using the red light emitting diode 12, it goes without saying that a red phosphor may also be used.

The white light emitting diode 11 of the light source 10a is composed of a COB (chip on board) type LED element, and has multiple blue LEDs that are bare chips (LED chips) mounted on a board, and a sealing material that seals the blue LEDs and contains a yellow phosphor. The white light emitting diode 11 emits white light by combining blue light with light whose wavelength has been converted by the yellow phosphor. The white light emitting diode 11 of the light source 10a is an RGB three-color LED light source 10a, and may emit three monochromatic lights of red light, blue light, and green light, or may emit white light obtained by dimming these three monochromatic lights.

The light source 10a may be a surface mount device (SMD) type LED element in which the LED is packaged, and may have a container (package), multiple LED chips mounted in the container, and a sealing member that seals the multiple LED chips. The sealing member is a translucent insulating resin material such as silicone resin. The sealing member may contain a light diffusing material such as silica and a filler dispersed therein.

[Control unit 20]
2, the control unit 20 has a dimming circuit and a color adjustment circuit for controlling an increase or decrease in the radiant energy emitted from the white light emitting diode 11 and the red light emitting diode 12 or the red phosphor. Specifically, the control unit 20 controls the current flowing through the white light emitting diode 11 and the red light emitting diode 12 and the number of light emitting diodes through which the current flows in order to control the radiant energy of the light to be irradiated to the plants.

As shown in Figs. 2 and 3, the control unit 20 controls the radiation energy of the red light emitted from the red light emitting diode 12 or red phosphor to be 1/2 or less of the radiation energy of the white light emitted from the white light emitting diode 11. This is to promote photosynthesis in plants and to suppress discoloration of plants, which occurs when the intensity of red light is too high compared to the intensity of white light in the light spectrum, making white plants look red and green plants look black. It is preferable that the control unit 20 controls the radiation energy of the red light to about 1/2 of the radiation energy of the white light.

The control unit 20 controls at least one of the irradiation range, irradiation direction, and illuminance of the white light and red light according to at least one of the size, shape, and growth stage of the plant.

The control unit 20 also acquires first information indicating at least one of the size, shape, and growth stage of the plant to be irradiated with the white light and red light. In other words, the control unit 20 acquires the first information indicating at least one of the size, shape, and growth stage of the plant by inputting it via the operation unit 40.

Figure 4a is a schematic diagram showing how the lighting device 10 controls light distribution to change the illumination range and illuminance, and Figure 4b is a schematic diagram showing how the lighting device 10 controls light distribution to change the illumination direction.

As shown in Figs. 2 and 4, for example, the control unit 20 controls the irradiation range and irradiation direction of the white light and red light (i.e., light) to irradiate the light to the growing point of the plant. The growing point is the crown part of the plant, the top part, and the vicinity thereof. Note that the vicinity may be an area of a few percent of the height H of the plant based on the growing point. The control unit 20 may also control the light to be irradiated to a part of the plant that is 1/2H or less of the height H of the plant (also called the lower leaves).

The control unit 20 controls the irradiation range and irradiation direction of the light emitted by the lighting device 10, thereby irradiating the light to the growth point of the plant. In other words, the control unit 20 controls the irradiation range of the light irradiated to the plant by controlling the light distribution angle of the light emitted by the lighting device 10. Specifically, the control unit 20 controls the irradiation range of the emitted light by adjusting the distance between the light distribution control lens mounted on the lighting device 10 and the light source 10a.

The control unit 20 also controls the light irradiation direction by irradiating the light emitted by the lighting device 10 onto the growth point of the plant. The irradiation direction is, for example, the optical axis direction of the light emitted by the lighting device 10, or the luminous intensity direction of the maximum luminous intensity of the light emitted by the lighting device 10. Specifically, as shown in FIG. 4b, the control unit 20 controls the irradiation direction by adjusting the posture of the lighting device 10 as shown by the two-dot chain line and solid line by driving and controlling an actuator (not shown). The irradiation direction may also intersect the growth point of the plant, or may substantially intersect the growth point of the plant.

The control of the illumination range and illumination direction may be achieved by a person replacing the light distribution control lens of the lighting device 10 or by a person adjusting the illumination direction of the lighting device 10.

The control unit 20 has a first mode, a second mode, a third mode, a fourth mode, and a fifth mode.

The first mode is a mode that is expected to have the effect of promoting plant growth by irradiating light to the growth point of the plant. In the first mode for promoting plant growth, the control unit 20 controls the illuminance of the light emitted by the lighting device 10 to irradiate the growth point of the plant with white light and red light of 1200 lx or more. The upper limit of the illuminance irradiated to the growth point of the plant is, for example, approximately 10,000 lx.

The second mode is a mode that is expected to have the effect of maintaining grass vigor by irradiating light to the growth point of the plant. In the second mode for maintaining grass vigor, the control unit 20 controls the illuminance of the light emitted by the lighting device 10 to irradiate the growth point of the plant with white light and red light of 600 lx or more and 1000 lx or less.

The third mode is a mode that is expected to have the effect of maintaining the vigor of the plant and suppressing the occurrence of leaf fall by irradiating light to a portion of the plant that is less than 1/2 of its height H. In the third mode for maintaining the vigor of the plant, the control unit 20 controls the irradiation range and irradiation direction of the white light and red light emitted by the lighting device 10 to irradiate the white light and red light to a portion of the plant that is less than 1/2 of its height H.

Figure 5a is a schematic diagram showing how the lighting device 10 controls light distribution to irradiate 1200 lx of light onto the growing point and 600 lx of light onto the lower leaves of the plant, and Figure 5b is a schematic diagram showing how the lighting device 10 controls light distribution to irradiate 600 lx to 1000 lx of light onto the growing point and 600 lx of light onto the lower leaves of the plant.

The fourth mode is a mode that is expected to promote plant growth like the first mode, while suppressing leaf drop like the third mode. In the fourth mode, which simultaneously executes both the first and third modes, the control unit 20 controls the irradiation range, irradiation direction, and illuminance of the white light and red light emitted by the lighting device 10 to irradiate the growth point of the plant with white light and red light of 1200 lx or more, and to irradiate a portion of the plant that is less than 1/2 of the height H of the plant with white light and red light of 600 lx or more, but less than the illuminance irradiated to the growth point of the plant.

The fifth mode is a mode that is expected to maintain the plant's vigor and suppress the occurrence of leaf fall by irradiating the growth point of the plant with light and irradiating a portion of the plant that is less than 1/2 of the plant's height H. As the fifth mode for maintaining the plant's vigor and suppressing the occurrence of leaf fall, the control unit 20 controls the irradiation range, irradiation direction, and illuminance of the white light and red light emitted by the lighting device 10 to irradiate the growth point of the plant with white light and red light of 600 lx or more and 1000 lx or less, and to irradiate a portion of the plant that is less than 1/2 of the plant's height with white light and red light of 600 lx or more.

In this way, in the fourth and fifth modes, light is irradiated over the range from the upper leaves to the lower leaves of the plant.

As shown in FIG. 2, the control unit 20 also has one or more timers 21. Each timer 21 corresponds one-to-one with one or more lighting devices 10, and is a timer for controlling the lighting time of each lighting device 10. For example, when a predetermined time has elapsed, the timer 21 turns the corresponding lighting device 10 on or off, or changes the illuminance to a preset value.

In addition, the control unit 20 reads the lighting schedule stored in the memory unit 30 and controls each lighting device 10 according to the lighting schedule.

[Memory unit 30]
The storage unit 30 stores a lighting schedule for turning on or off each of the lighting devices 10. The storage unit 30 also stores first information indicating at least one of the size, shape, and growth stage of the plant to be irradiated with light. The storage unit 30 is configured with a hard disk drive (HDD), a semiconductor memory, or the like.

[Operation unit 40]
The operation unit 40 controls the operation of each lighting device 10 via the control unit 20. The operation unit 40 receives input by a user's operation or an input from an external device other than the lighting system 1, and outputs an instruction according to the received input to the control unit 20. In other words, the operation unit 40 controls the operation of each lighting device 10 according to the received input.

The operation unit 40 may be a sensor such as an imaging device that captures an image of a plant to obtain information indicating at least one of the size, shape, and growth stage of the plant, or may be an operation terminal that obtains information through input by a user's operation.

[Power supply unit 50]
The power supply unit 50 is a power supply module having a lighting circuit that supplies power for lighting the lighting device 10. The power supply unit 50 converts AC current supplied from an external power source such as a commercial power source via a ceiling hook and an adapter into DC power of a predetermined level by rectifying, smoothing, stepping down, etc. The power supply unit 50 supplies the converted DC current to the lighting device 10 via a lead wire, etc. The power supply unit 50 may be combined with a dimming circuit, a boost circuit, etc. The power supply unit 50 may be mounted on the lighting device 10, in which case the power supply unit 50 of the present embodiment may not supply power to the lighting device 10.

<Experimental Results>
The following are the results of an experiment evaluating the plant growth, the effect of maintaining plant vigor, and the total number of fallen leaves when the first, second, and third lights were irradiated on the plant. In this experiment, a jasmine plant with a height of 1 m was used.

The first lighting is a case where the light of the base lighting by the normal lighting device 10 installed indoors is irradiated to the plant, regardless of the light irradiation method for plant growth, the lighting device 10, and the lighting system 1 of this embodiment. The second lighting is a case where the fourth mode is further executed on the base lighting. That is, the second lighting is a case where, in addition to the irradiation of the light by the base lighting, the growth point of the plant is irradiated with 1200 lx of white light and red light, and 600 lx of white light and red light is irradiated to a part of the plant that is 1/2 or less of its height. The third lighting is a case where the fifth mode is further executed on the base lighting. That is, in addition to the irradiation of the light by the base lighting, the third lighting is a case where, in addition to the irradiation of the light by the base lighting, the growth point of the plant is irradiated with 600 lx to 1000 lx of white light and red light, and 600 lx of white light and red light is irradiated to a part of the plant that is 1/2 or less of its height.

The experimental results under these conditions are shown in Figure 6.

Figure 6 is a diagram showing the relationship between plant elongation and the number of days when the lighting device 10 of the lighting system 1 according to embodiment 1 irradiates the plant with light. In Figure 6, the horizontal axis represents the number of days (hours) that the plant is irradiated with light, and the vertical axis represents the plant elongation when the plant is irradiated with light. The case of the first lighting is shown by a solid line, the case of the second lighting is shown by a dashed line, and the case of the third lighting is shown by a dashed line.

Figure 6 shows that the second lighting had the greatest effect on plant growth compared to the first and third lighting, with the plants growing taller as the days went by. It was also found that the first and third lighting did not significantly affect plant growth, and the plants grew taller as the days went by, but this was not as noticeable as when the plants were illuminated with the second lighting.

Figure 7 is a diagram showing the relationship between the number of leaves that fall from a plant and the number of days when the lighting device 10 of the lighting system 1 according to embodiment 1 irradiates the plant with light. In Figure 7, the horizontal axis is the number of days that the plant is irradiated with light, and the vertical axis is the total number of leaves that fall when the plant is irradiated with light.

Figure 7 shows that the first lighting increases the total number of fallen leaves more than the second and third lighting. It was also found that the number of fallen leaves does not increase significantly over time with the second and third lighting.

<Processing>
Hereinafter, a light irradiation method for growing a plant, and processing of the lighting device 10 and the lighting system 1 according to the present embodiment will be described.

Figure 8 is a flowchart showing the processing of the lighting system 1 according to embodiment 1.

First, as shown in FIG. 8, the control unit 20 of the lighting system 1 acquires first information indicating at least one of the size, shape, and growth stage of the plant to be irradiated with light (S11). The first information is stored in, for example, the storage unit 30.

Next, the control unit 20 determines the irradiation range, irradiation direction, and illuminance of the light emitted by the lighting device 10 according to at least one of the size, shape, and growth stage of the plant indicated in the first information (S12). For example, the control unit 20 determines the irradiation range, irradiation direction, and illuminance of the light by reading a table stored in the storage unit 30. In other words, the control unit 20 determines the mode for controlling the lighting device 10 from among the first mode to the fifth mode. In the table, modes corresponding to the irradiation range, irradiation direction, and illuminance of the light corresponding to at least one of the size, shape, and growth stage of the plant are preset.

Next, the control unit 20 controls the lighting device 10 according to the determined mode (S13). As a result, the lighting device 10 irradiates the target plant with light having an irradiation range, irradiation direction, and illuminance according to the determined mode. Then, the control unit 20 ends the process.

<Action and effect>
Next, the effects of the light irradiation method for plant growth, the lighting device 10, and the lighting system 1 according to the present embodiment will be described.

As described above, the light irradiation method for plant growth in this embodiment includes irradiating a plant with white light and red light using a white light-emitting diode 11 that emits white light and a red light-emitting diode 12 or a red phosphor that emits red light, controlling the radiant energy of the red light emitted from the red light-emitting diode 12 or the red phosphor to be half or less of the radiant energy of the white light emitted from the white light-emitting diode 11, and controlling at least one of the irradiation range, irradiation direction, and illuminance of the white light and the red light according to at least one of the size, shape, and growth stage of the plant.

This allows the plant to be irradiated with red light, which is effective for plant photosynthesis and flower bud formation, and light irradiation can be performed that is more effective for plant growth and maintaining plant vigor than when only white light is irradiated to the plant. In other words, the light irradiation method for plant growth can bring the plant into the desired state.

In addition, by making the radiation energy of red light half or less of that of white light, plants illuminated with the light do not appear reddish to people. In other words, this light irradiation method for plant growth is unlikely to impair the appearance of the plants.

Therefore, this method of applying light for plant growth can help plants grow, maintain their vigor, and improve their appearance.

The lighting device 10 in this embodiment includes a light source 10a that has a white light-emitting diode 11 that emits white light and a red light-emitting diode 12 or a red phosphor that emits red light, and irradiates the white light and red light to the plant, and a control unit 20 that controls the radiant energy of the red light emitted from the red light-emitting diode 12 or the red phosphor to be half or less of the radiant energy of the white light emitted from the white light-emitting diode 11, and controls at least one of the irradiation range, irradiation direction, and illuminance of the white light and red light according to at least one of the size, shape, and growth stage of the plant.

This lighting device 10 also provides the same effects as the light irradiation method for plant growth described above.

The lighting system 1 in this embodiment includes a lighting device 10 having a white light-emitting diode 11 that emits white light and a red light-emitting diode 12 or a red phosphor that emits red light, and irradiating the white light and red light to the plant, and a control unit 20 that controls the radiant energy of the red light emitted from the red light-emitting diode 12 or the red phosphor to be half or less of the radiant energy of the white light emitted from the white light-emitting diode 11, and controls at least one of the irradiation range, irradiation direction, and illuminance of the white light and the red light according to at least one of the size, shape, and growth stage of the plant.

This lighting system 1 also provides the same effects as the light irradiation method for plant growth described above.

In addition, the light irradiation method for plant growth in this embodiment controls the irradiation range and irradiation direction of the white light and red light to irradiate the growth point of the plant with the white light and red light.

This will help promote plant growth and allow the plant to reach the desired condition.

In addition, in the lighting device 10 of this embodiment, the control unit 20 controls the irradiation range and irradiation direction of the white light and red light to irradiate the white light and red light onto the growth point of the plant.

This lighting device 10 also provides the same effects as the light irradiation method for plant growth described above.

In addition, in the light irradiation method for plant growth in this embodiment, the irradiation range and direction of the white light and red light are controlled to irradiate an area of the plant that is less than half its height.

This makes it easier to maintain the plant's vigor in the desired condition, which extends the plant's viewing period (the period during which it looks good). It also helps prevent the plant from losing its leaves.

In addition, the light irradiation method for plant growth in this embodiment irradiates the growth point of the plant with white light and red light of 1200 lx or more, and irradiates a portion of the plant up to 1/2 of its height with white light and red light of 600 lx or more, which is less than the illuminance of the white light and red light irradiated to the growth point of the plant.

This promotes plant growth and inhibits defoliation. This prevents the plant's appearance from being marred by defoliation and reduces the need to clean up defoliation more frequently.

In addition, the light irradiation method for plant growth in this embodiment irradiates the growth point of the plant with white light and red light of 600 lx to 1000 lx, and irradiates a portion of the plant up to 1/2 of its height with white light and red light of 600x or more.

This allows the plant's vigor to be maintained while preventing defoliation. This makes it easier to maintain the plant in the desired condition, and extends the plant's viewing period (the period during which it looks good).

In addition, the light irradiation method for plant growth in this embodiment irradiates the plant growth point with white light and red light of 1200 lx or more when promoting plant growth, and irradiates the plant with white light and red light when maintaining plant vigor, irradiates the plant growth point with white light and red light of 600 lx to 1000 lx, and irradiates a portion of the plant that is less than 1/2 of its height with white light and red light.

This allows you to encourage plant growth and maintain plant vigor at the desired time. This makes it easier to keep the plant in the desired condition, and extends the plant's viewing period (the period during which it looks good).

(Embodiment 2)
<Configuration>
The light irradiation method for plant growth, the configuration of the lighting device 10, and the lighting system 1 in the present embodiment will be described.

Fig. 9A is a schematic diagram showing how the lighting devices 10 of the lighting system 1 according to embodiment 2 are placed above and below a plant and how they irradiate the plant with light. Fig. 9B is a schematic diagram showing the appearance of the plant when the lighting device 10 on the upper side irradiates the plant with light and the appearance of the plant when the lighting device 10 on the lower side irradiates the plant with light.

This embodiment differs from embodiment 1 in that multiple lighting devices 10 are used.

Unless otherwise specified, other configurations in this embodiment are the same as those in embodiment 1, and the same components are given the same reference numerals and detailed descriptions of the components are omitted.

In this embodiment, as shown in Figures 2, 9A, and 9B, a first lighting device 10b1, which is a lighting device 10, is placed at a position higher than the plant, and a second lighting device 10b2, which is a lighting device 10, is placed at a position equal to or less than 1/2 the height H of the plant.

The first lighting device 10b1 is positioned so that it irradiates the plant with white light and red light from above to below. Specifically, the first lighting device 10b1 is positioned so that the irradiation direction of the irradiated white light and red light forms an angle θ of 25° to 60° with respect to the horizontal direction. The first lighting device 10b1 is supported by, for example, a ceiling, a wall, a stand, etc.

The second lighting device 10b2 is positioned so that it irradiates the plant with white light and red light from below to above. Specifically, the second lighting device 10b2 is positioned so that the irradiation direction of the irradiated white light and red light forms an angle θ of 30° to 70° with respect to the horizontal direction. The second lighting device 10b2 is supported by, for example, a floor, a wall, etc.

In this way, by shining light on the plant from above and below, the light is also irradiated onto the leaves deep inside the plant. In other words, the light is also irradiated onto the leaves deep inside the plant. Also, as shown in Figure 9B, because light is irradiated onto each of the plant's leaves, the light is reflected by each leaf, making the entire plant appear to be shining.

The control unit 20 controls the first lighting device 10b1 and the second lighting device 10b2 to change the direction of irradiation of the white light and red light according to the size and shape of the plant.

The control unit 20 also uses the first lighting device 10b1 and the second lighting device 10b2 to control the illuminance and on/off of the white light and red light irradiated onto the plants.

<Experimental Results>
The following are the results of an experiment evaluating plant growth, plant vigor maintenance effect, total number of fallen leaves, and photosynthetic sensitivity when light is irradiated to the growing point and lower leaves of the plant. In this experiment, jasmine plants with a height H of 1 m were used as plants, and the illuminance was changed from 300 lx to 1500 lx and the plants were grown for 30 days. In addition, a measuring device for Meiwafosis (LI-6400XT) was used as a means for measuring photosynthetic sensitivity. The photosynthetic sensitivity was calculated as the average of 20 leaves.

Fig. 10 is a diagram showing the relationship between plant elongation and illuminance, the relationship between the number of fallen leaves and illuminance, and the relationship between photosynthetic sensitivity and illuminance when the first lighting device 10b1 of the lighting system 1 according to embodiment 2 irradiates light to the growing point of the plant. Fig. 10 shows the case where light is irradiated to the growing point. In Fig. 10, the horizontal axis is the illuminance of light irradiated to the plant, the vertical axis (corresponding to the solid line) is the grown length of the plant (elongation cm), the vertical axis (corresponding to the dashed line with small intervals) is the total number of fallen leaves of the plant, and the vertical axis (corresponding to the dashed line with large intervals) is the photosynthetic sensitivity of the plant (μmol CO ₂ m ^-2 s ^-1 ).

It was found that the higher the illuminance applied to the plant, the greater the plant's growth, and therefore that it has the effect of promoting plant growth. It was also found that the total number of fallen leaves from the plant decreased as the illuminance increased, with the total number of fallen leaves at an illuminance of 600 lx or more being dramatically lower than the total number of fallen leaves at an illuminance of less than 600 lx. It was also found that the higher the illuminance, the greater the photosynthetic sensitivity of the plant.

In particular, at illuminance levels of 600lx to 1000lx (illuminance sufficient to maintain plant vigor), plant growth slowed, fewer leaves fell, and the rate of increase in photosynthetic sensitivity was slower than at illuminance levels below 600lx, demonstrating the effectiveness of maintaining plant vigor.

In addition, it was found that at illuminance levels of 1200 lx or more (growth illuminance), plants grew faster, there was less leaf fall, and the photosynthetic sensitivity was higher than at illuminance levels below 1200 lx, which was effective in promoting plant growth.

Fig. 11 is a diagram showing the relationship between plant elongation and illuminance, the relationship between the number of fallen leaves and illuminance, and the relationship between photosynthetic sensitivity and illuminance when the second lighting device 10b2 of the lighting system 1 according to embodiment 2 irradiates light to the lower leaves of the plant. Fig. 11 shows the case where light is irradiated to the lower leaves. The scale of the vertical axis in Fig. 11 is the same as that of the vertical axis in Fig. 10. In Fig. 11, the horizontal axis is the illuminance of light irradiated to the plant, the vertical axis (corresponding to the solid line) is the grown length of the plant (elongation cm), the vertical axis (corresponding to the dashed line with small intervals) is the total number of fallen leaves of the plant, and the vertical axis (corresponding to the dashed line with large intervals) is the photosynthetic sensitivity of the plant (μmol CO ₂ m ^-2 s ^-1 ).

It was found that the higher the illuminance applied to the plant, the slightly greater the plant's growth. When light was applied to the lower leaves, it did not have the same effect on plant growth as when light was applied to the plant's growing point, but it was found that the plant's vigor was maintained. In addition, it was found that the total number of fallen leaves from the plant also decreased as the illuminance increased, with the total number of fallen leaves at an illuminance of 600 lx or more decreasing more dramatically than the total number of fallen leaves at an illuminance of less than 600 lx. It was also found that the higher the illuminance, the higher the photosynthetic sensitivity of the plant. However, when light was applied to the lower leaves, the effect of increasing photosynthetic sensitivity was more gradual than when light was applied to the plant's growing point, and it was found to have the effect of maintaining the plant's vigor.

<Action and effect>
Next, the effects of the light irradiation method for plant growth, the lighting device 10, and the lighting system 1 according to the present embodiment will be described.

As described above, the light irradiation method for plant growth in this embodiment changes the irradiation direction of the white light and red light depending on the size and shape of the plant. When the lighting device 10 having the white light emitting diode 11 and the red light emitting diode 12 or the red phosphor is placed at a position higher than the plant, the irradiation direction of the white light and red light emitted by the lighting device 10 has an angle of 25° to 60° with respect to the horizontal direction, and when the lighting device 10 is placed at a position less than 1/2 the height of the plant, the irradiation direction of the white light and red light emitted by the lighting device 10 has an angle of 30° to 70° with respect to the horizontal direction.

By irradiating the plant with light from above and below, it is possible to irradiate the light even to leaves deep inside the plant. In other words, the leaves deep inside the plant can more easily carry out photosynthesis, which can prevent defoliation. Also, as shown in FIG. 9B, because light is irradiated onto each of the plant's leaves, the light is reflected by each leaf, making the plant appear to be shining as a whole, improving its appearance.

In addition, the light irradiation method for plant growth in this embodiment uses multiple lighting devices 10 placed at a position higher than the plant and at a position less than half the height of the plant to control the illuminance and on/off of the white light and red light irradiated to the plant.

By irradiating the plant with light from above and below, the plant can efficiently carry out photosynthesis.

It is also possible to control the on/off of the lighting device 10 and the illuminance of the light emitted by the lighting device 10. This allows plants to grow and maintain their vigor efficiently, while also improving the appearance of the plants.

This embodiment also provides the same effects as embodiment 1.

(Embodiment 3)
<Configuration>
The configuration of a lighting system 1a according to the present embodiment will be described.

Figure 12 is a block diagram of a lighting system 1a according to embodiment 3.

As shown in FIG. 12, this embodiment differs from the first embodiment in that it has a first detection unit 61 and a second detection unit 62 that detect the state of the plant.

Unless otherwise specified, other configurations in this embodiment are the same as those in embodiment 1, and the same components are given the same reference numerals and detailed descriptions of the components are omitted.

The lighting system 1a includes one or more lighting devices 10, a control unit 20, a memory unit 30, an operation unit 40, and a power supply unit 50, as well as a first detection unit 61 and a second detection unit 62.

The first detection unit 61 detects the state of the plant and obtains first information indicating at least one of the size, shape, and growth stage of the plant. The first detection unit 61 is, for example, an imaging device, a brightness sensor, etc., and recognizes at least one of the size, shape, and growth stage of the plant by capturing an image of the plant, and obtains first information indicating at least one of the size, shape, and growth stage of the plant. The first detection unit 61 outputs the detected first information to the control unit 20. The first detection unit 61 is an example of a detection unit.

The second detection unit 62 obtains second information indicating the photosynthetic sensitivity of the plant due to the light irradiated by the lighting device 10. The second detection unit 62 is, for example, a photosynthetic sensor that measures the intensity of the plant's chlorophyll fluorescence. The second detection unit 62 outputs the detected second information to the control unit 20.

The control unit 20 controls at least one of the light distribution, irradiation direction, and illuminance of the white light and red light irradiated to the plant based on the acquired first information and second information.

For example, the control unit 20 can determine whether or not the plant is growing based on the first information. If the control unit 20 determines that the plant is growing, it executes the third mode, the third mode, or the fifth mode to maintain the plant's vigor. Furthermore, if the control unit 20 determines that the plant is not growing based on the first information, it executes the first mode or the fourth mode to promote the plant's growth.

The control unit 20 can also determine whether the degree of photosynthesis of the plant is greater than a predetermined value based on the second information. When the degree of photosynthesis of the plant is greater than the predetermined value, the control unit 20 executes the third mode or the fifth mode if it wants to maintain the plant's vigor, and executes the first mode or the fourth mode or executes the current control process if it wants to promote plant growth. When the degree of photosynthesis of the plant is less than the predetermined value, the control unit 20 executes the second mode, the third mode, or the fifth mode if it wants to maintain the plant's vigor, and executes the first mode or the fourth mode if it wants to promote plant growth.

<Processing>
The light irradiation method for growing plants, the lighting device 10, and the lighting system 1a according to the present embodiment will be described below.

Figure 13 is a flowchart showing the processing of lighting system 1a according to embodiment 3.

First, as shown in FIG. 13, the first detection unit 61 detects the state of the plant. That is, the first detection unit 61 detects at least one of the size, shape, and growth stage of the plant to obtain first information indicating at least one of the size, shape, and growth stage of the plant (S21). The first detection unit 61 outputs the detected first information to the control unit 20. Then, from step S12 onwards, the same process as in FIG. 8 is performed.

<Experimental Results>
The following are experimental results evaluating plant growth, vigor maintenance, total number of fallen leaves, and photosynthetic sensitivity when light was irradiated to the growing point and lower leaves of the plant. In this experimental result, a jasmine plant with a height of 1 m was used, and light was irradiated by changing the irradiation angle of the optical axis of the lighting device 10 with respect to the horizontal plane from 0° to 80°. In addition, a measuring device from Meiwafosis (LI-6400XT) was used as a means for measuring photosynthetic sensitivity, and a measuring device from Komica Minolta (CA-2500) was used as a means for measuring luminance. In addition, the photosynthetic sensitivity was calculated as the average of 20 leaves.

Figure 14 shows the relationship between photosynthetic sensitivity and irradiation angle, and the relationship between brightness and irradiation angle when the first lighting device 10b1 on the upper side irradiates light onto a plant.

In Fig. 14, the first lighting device 10b1 was placed at a higher position than the plant to irradiate the plant with light. In Fig. 14, the horizontal axis represents the irradiation angle of the optical axis of the first lighting device 10b1 with respect to the horizontal plane when the plant is irradiated with light from above to below, the left vertical axis (corresponding to the solid line) represents the photosynthetic sensitivity of the plant (μmol CO ₂ m ^-2 s ^-1 ), and the right vertical axis (corresponding to the dashed line) represents the luminance (cd/m ² ).

For both the solid and dashed lines, it was found that the photosynthetic sensitivity and brightness increased when the irradiation angle was between 20° and 70°. In particular, it was found that the photosynthetic sensitivity and brightness increased when the irradiation angle was between 25° and 60°.

Figure 15 shows the relationship between photosynthetic sensitivity and irradiation angle, and the relationship between brightness and irradiation angle when the second lighting device 10b2 on the lower side irradiates light onto a plant.

In Fig. 15, the plant was irradiated with light using the second lighting device 10b2 placed at a position equal to or less than half the height of the plant. In Fig. 15, the horizontal axis represents the irradiation angle of the optical axis of the second lighting device 10b2 with respect to the horizontal plane when the plant was irradiated with light from below to above, the vertical axis on the left (corresponding to the solid line) represents the photosynthetic sensitivity of the plant (μmol CO ₂ m ^-2 s ^-1 ), and the vertical axis on the right (corresponding to the dashed line) represents the luminance (cd/m ² ).

For both the solid and dashed lines, it was found that the photosynthetic sensitivity and brightness increased when the irradiation angle was between 25° and 75°. In particular, it was found that the photosynthetic sensitivity and brightness increased when the irradiation angle was between 30° and 70°.

<Action and effect>
Next, the effects of the lighting system 1a according to the present embodiment will be described.

As described above, the lighting system 1a in this embodiment further includes a first detection unit 61 that detects at least one of the size, shape, and growth stage of the plant. The control unit 20 then acquires first information indicating at least one of the size, shape, and growth stage of the plant from the first detection unit 61, and controls at least one of the irradiation range, irradiation direction, and illuminance of the white light and red light irradiated to the plant based on the acquired first information.

This makes it possible to control at least one of the light distribution, irradiation direction, and illuminance of the white light and red light irradiated onto the plant based on at least one of the plant's state, which is the size, shape, and growth stage of the plant. This makes it possible to optimize the appearance of the plant and optimize the state of the plant by reducing the load on the plant.

This embodiment also provides the same effects as embodiment 1.

(Other variations, etc.)
Although the present disclosure has been described above based on the embodiments, the present disclosure is not limited to these embodiments.

For example, in the light irradiation method for plant growth, the lighting device, and the lighting system according to the above-mentioned first to third embodiments, the control unit is provided as a device separate from the lighting device, but may also be mounted on the lighting device.

The light irradiation methods for plant growth according to the above-mentioned embodiments 1 to 3 may be realized by a program using a computer, and such a program may be stored in a storage device.

Furthermore, each processing unit included in the light irradiation method for plant growth, the lighting device, and the lighting system according to the above-mentioned first to third embodiments is realized as an LSI, which is typically an integrated circuit. These may be individually implemented as single chips, or may be integrated into a single chip that includes some or all of them.

In addition, the integrated circuit is not limited to LSI, but may be realized by a dedicated circuit or a general-purpose processor. It is also possible to use an FPGA (Field Programmable Gate Array) that can be programmed after LSI manufacturing, or a reconfigurable processor that can reconfigure the connections and settings of circuit cells inside the LSI.

In the above first to third embodiments, each component may be configured with dedicated hardware, or may be realized by executing a software program suitable for each component. Each component may be realized by a program execution unit such as a CPU or processor reading and executing a software program recorded on a recording medium such as a hard disk or semiconductor memory.

Furthermore, all the numbers used above are merely examples to specifically explain this disclosure, and the embodiments of this disclosure are not limited to the numbers shown as examples.

The division of functional blocks in the block diagram is just one example, and multiple functional blocks may be realized as one functional block, one functional block may be divided into multiple blocks, or some functions may be transferred to other functional blocks. In addition, the functions of multiple functional blocks with similar functions may be processed in parallel or in a time-shared manner by a single piece of hardware or software.

The order in which each step in the flowchart is performed is merely an example to specifically explain the present disclosure, and orders other than those described above may also be used. Some of the steps may also be performed simultaneously (in parallel) with other steps.

In addition, this disclosure also includes forms obtained by applying various modifications to embodiments 1 to 3 that would come to mind by a person skilled in the art, and forms realized by arbitrarily combining the components and functions of embodiments 1 to 3 without departing from the spirit of this disclosure.

Reference Signs List 1, 1a Illumination system 10 Illumination device 10a Light source 11 White light emitting diode 12 Red light emitting diode 20 Control unit 61 First detection unit (detection unit)

Claims (16)

A white light emitting diode that emits white light and a red light emitting diode or a red phosphor that emits red light are used to irradiate the white light and the red light to the plant;
controlling the radiant energy of the red light emitted from the red light emitting diode or the red phosphor to be equal to or less than half the radiant energy of the white light emitted from the white light emitting diode;
controlling at least one of an irradiation range, an irradiation direction, and an illuminance of the white light and the red light according to at least one of a size, a shape, and a growth stage of the plant;
by controlling at least one of an irradiation range, an irradiation direction, and an illuminance of the white light and the red light, a mode for promoting growth of the plant and a mode for suppressing leaf loss of the plant are executed;
executing at least one of a mode for maintaining the vigor of the plant and a mode for maintaining the vigor of the plant and suppressing defoliation of the plant by controlling at least one of an irradiation range, an irradiation direction, and an illuminance of the white light and the red light ;
When executing a mode for promoting the growth of the plant, irradiating a growth point of the plant including a top portion of the plant with the white light and the red light at 1200 lx or more and less than 3000 lx;
When executing a mode for maintaining the vigor of the plant, irradiating a growth point of the plant with the white light and the red light at 600 lx or more and 1000 lx or less;
A light irradiation method for plant growth, comprising: irradiating a portion of the plant that is equal to or less than 1/2 of a height H of the plant with the white light and the red light when executing a mode for maintaining the plant vigor and suppressing leaf fall of the plant. The white light and the red light are irradiated to a part of the plant that is equal to or less than half of the height of the plant by controlling an irradiation range and an irradiation direction of the white light and the red light.
Irradiating the growing point of the plant with the white light and the red light at 1200 lx or more;
2. The light irradiation method for plant cultivation according to claim 1, comprising irradiating a portion of the plant that is equal to or less than 1/2 of its height with the white light and the red light of 600 lx or more, which is lower than the illuminance of the white light and the red light irradiated to a growth point of the plant. Irradiating the white light and the red light at 600 lx or more and 1000 lx or less to the growth point of the plant,
The light irradiation method for plant cultivation according to claim 1 or 2 , comprising irradiating a portion of the plant that is equal to or less than a half of its height with the white light and the red light of 600 lx or more. The light irradiation method for plant growth according to any one of claims 1 to 3, wherein the white light and the red light are irradiated to a growth point of the plant by controlling an irradiation range and an irradiation direction of the white light and the red light. Irradiating the white light and the red light at 600 lx or more and 1000 lx or less to the growth point of the plant,
The light irradiation method for plant growth according to claim 1 , wherein the white light and the red light are irradiated at 600 lx or more to a portion of the plant that is equal to or less than half of its height. When promoting the growth of the plant, the white light and the red light are irradiated at a growth point of the plant with 1200 lx or more of the white light and the red light,
When maintaining the vigor of the plant,
Irradiating the plant with the white light and the red light;
The light irradiation method for plant growth according to any one of claims 2 to 4 , wherein the white light and the red light are irradiated to a growth point of the plant with 600 lx or more and 1000 lx or less, and the white light and the red light are irradiated to a portion of the plant that is equal to or less than 1/2 of its height. changing the irradiation direction of the white light and the red light according to the size and shape of the plant;
When a lighting device having the white light emitting diode and the red light emitting diode or the red phosphor is placed at a position higher than the plant, the irradiation direction of the white light and the red light emitted by the lighting device is at an angle of 25° to 60° with respect to the horizontal direction;
7. The light irradiation method for plant growth according to claim 1, wherein, when the lighting device is disposed at a position equal to or less than ½ of the height of the plant, the irradiation direction of the white light and the red light emitted by the lighting device has an angle of 30 ° to 70° with respect to the horizontal direction. 8. The light irradiation method for plant cultivation according to claim 7, further comprising controlling an illuminance of the white light and the red light irradiated to the plant to be 600 lx or more using a plurality of the lighting devices disposed at a position higher than the plant and at a position equal to or lower than 1/2 the height of the plant, in order to cultivate the plant and maintain its vigor, and controlling the turning on and off of the white light and the red light irradiated to the plant. a light source having a white light emitting diode that emits white light and a red light emitting diode or a red phosphor that emits red light, the light source irradiating the white light and the red light to a plant;
a control unit that controls the radiant energy of the red light emitted from the red light emitting diode or the red phosphor to be half or less of the radiant energy of the white light emitted from the white light emitting diode, and controls at least one of an irradiation range, an irradiation direction, and an illuminance of the white light and the red light in accordance with at least one of a size, a shape, and a growth stage of the plant,
The control unit is
by controlling at least one of an irradiation range, an irradiation direction, and an illuminance of the white light and the red light, a mode for promoting growth of the plant and a mode for suppressing leaf loss of the plant are executed;
by controlling at least one of an irradiation range, an irradiation direction, and an illuminance of the white light and the red light, at least one of a mode for maintaining the vigor of the plant and a mode for maintaining the vigor of the plant and suppressing defoliation of the plant is executed ;
The light source is
When executing a mode for promoting the growth of the plant, the white light and the red light are irradiated at 1200 lx or more and less than 3000 lx to a growth point of the plant including a top part of the plant,
When executing a mode for maintaining the vigor of the plant, the white light and the red light are irradiated to a growth point of the plant with light of 600 lx or more and 1000 lx or less;
a lighting device which irradiates a portion of the plant that is equal to or less than half of a height H of the plant with the white light and the red light when executing a mode for maintaining the vigor of the plant and suppressing leaf fall of the plant ; The control unit controls the irradiation range and irradiation direction of the white light and the red light, so that the light source irradiates the white light and the red light to a portion of the plant that is equal to or less than half of its height,
The light source is
Irradiating the growing point of the plant with the white light and the red light at 1200 lx or more;
The lighting device according to claim 9 , wherein the white light and the red light are irradiated to a portion of the plant that is equal to or less than half of the height of the plant, and the illuminance of the white light and the red light is 600 lx or more, which is lower than the illuminance of the white light and the red light irradiated to a growth point of the plant. The light source is
Irradiating the white light and the red light at 600 lx or more and 1000 lx or less to the growth point of the plant,
The lighting device according to claim 9 or 10 , wherein the white light and the red light are irradiated at 600 lx or more to a portion of the plant that is equal to or less than half of the plant's height. The lighting device according to any one of claims 9 to 11 , wherein the control unit controls an irradiation range and an irradiation direction of the white light and the red light to irradiate the white light and the red light onto a growth point of the plant. A lighting device having a white light emitting diode that emits white light and a red light emitting diode or a red phosphor that emits red light, the lighting device irradiating the white light and the red light to a plant;
a control unit that controls the radiant energy of the red light emitted from the red light emitting diode or the red phosphor to be half or less of the radiant energy of the white light emitted from the white light emitting diode, and controls at least one of an irradiation range, an irradiation direction, and an illuminance of the white light and the red light in accordance with at least one of a size, a shape, and a growth stage of the plant,
The control unit is
by controlling at least one of an irradiation range, an irradiation direction, and an illuminance of the white light and the red light, a mode for promoting growth of the plant and a mode for suppressing leaf loss of the plant are executed;
by controlling at least one of an irradiation range, an irradiation direction, and an illuminance of the white light and the red light, at least one of a mode for maintaining the vigor of the plant and a mode for maintaining the vigor of the plant and suppressing defoliation of the plant is executed ;
The lighting device includes:
When executing a mode for promoting the growth of the plant, the white light and the red light are irradiated at 1200 lx or more and less than 3000 lx to a growth point of the plant including a top part of the plant,
When executing a mode for maintaining the vigor of the plant, the white light and the red light are irradiated to a growth point of the plant with light of 600 lx or more and 1000 lx or less;
a lighting system for irradiating a portion of the plant that is equal to or less than half of a height H of the plant with the white light and the red light when executing a mode for maintaining vigor of the plant and suppressing leaf fall of the plant . The control unit controls an irradiation range and an irradiation direction of the white light and the red light, so that the lighting device irradiates the white light and the red light to a portion of the plant that is equal to or less than half of the height of the plant;
The lighting device includes:
Irradiating the growing point of the plant with the white light and the red light at 1200 lx or more;
The lighting system according to claim 13 , wherein the white light and the red light are irradiated to a portion of the plant that is equal to or less than half of the height of the plant, and the illuminance of the white light and the red light is 600 lx or more, which is lower than the illuminance of the white light and the red light irradiated to a growing point of the plant. The lighting device includes:
Irradiating the white light and the red light at 600 lx or more and 1000 lx or less to the growth point of the plant,
The lighting system according to claim 13 or 14 , wherein the white light and the red light are irradiated at 600 lx or more to a portion of the plant that is equal to or less than half of its height. Further, a detection unit is provided that detects at least one of the size, shape, and growth stage of a plant,
The control unit obtains information indicating at least one of a size, a shape, and a growth stage of the plant from the detection unit in order to optimize a condition of the plant, and controls at least one of an irradiation range, an irradiation direction, and an illuminance of the white light and the red light to be irradiated to the plant based on the obtained information. The lighting system according to any one of claims 13 to 15 .

Images